CODES

ADOPTS WITH AMENDMENTS:

International Residential Code 2015 (IRC 2015)

Copyright

Preface

Acknowledgements

California Code of Regulations, Title 24

How to Distinguish Between Model Code Language and California Amendments

Maintenance

Code Development Committee Responsibilities (Letter Designations in Front of Section Numbers)

Effective Use of the International Residential Code

Part I Administrative

Chapter 1 Scope and Application

Part II Definitions

Chapter 2 Definitions

Part III Building Planning and Construction

Chapter 3 Building Planning

Chapter 4 Foundations

Chapter 5 Floors

Chapter 6 Wall Construction

Chapter 7 Wall Covering

Chapter 8 Roof-Ceiling Construction

Chapter 9 Roof Assemblies

Chapter 10 Chimneys and Fireplaces

Part IV Energy Conservation

Part V Mechanical

Part VI Fuel Gas

Part VII Plumbing

Part VIII Electrical

Part IX Referenced Standards

Chapter 44 Referenced Standards

Appendix A Sizing and Capacities of Gas Piping

Appendix B Sizing of Venting Systems Serving Appliances Equipped With Draft Hoods, Category I Appliances, and Appliances Listed for Use With Type B Vents

Appendix C Exit Terminals of Mechanical Draft and Direct-Vent Venting Systems

Appendix D Recommended Procedure for Safety Inspection of an Existing Appliance Installation

Appendix E Manufactured Housing Used as Dwellings

Appendix F Passive Radon Gas Controls

Appendix G Piping Standards for Various Applications

Appendix H Patio Covers

Appendix I Private Sewage Disposal

Appendix J Existing Buildings and Structures

Appendix K Sound Transmission

Appendix L Permit Fees

Appendix M Home Day Care—r-3 Occupancy

Appendix N Venting Methods

Appendix O Automatic Vehicular Gates

Appendix P Sizing of Water Piping System

Appendix Q Reserved

Appendix R Light Straw-Clay Construction

Appendix S Strawbale Construction

Appendix T RECOMMENDED PROCEDURE FOR WORST-CASE TESTING OF ATMOSPHERIC VENTING SYSTEMS UNDER N1102.4 OR N1105 CONDITIONS ≤ 5ACH 50

Appendix U Solar-Ready Provisions—detached One- And Two-Family Dwellings, Multiple Single- Family Dwellings (Townhouses)

Appendix V Swimming Pool Safety Act

Appendix W Areas Protected by the Facilities of the Central Valley Flood Protection Plan

History Note Appendix

Projects which disturb less than one acre of soil and are not part of a larger common plan of development which in total disturbs one acre or more, shall manage storm water drainage during construction in accordance with the California Green Building Standards Code, Chapter 4, Division 4.1.

Construction plans shall indicate how the site grading or drainage system will manage all surface water flows to keep water from entering buildings in accordance with the California Green Building Standards Code, Chapter 4, Division 4.1.

Buildings and structures, and parts thereof, shall be constructed to safely support all loads, including dead loads, live loads, roof loads, flood loads, snow loads, wind loads and seismic loads as prescribed by this code. The construction of buildings and structures in accordance with the provisions of this code shall result in a system that provides a complete load path that meets the requirements for the transfer of loads from their point of origin through the load-resisting elements to the foundation. Buildings and structures constructed as prescribed by this code are deemed to comply with the requirements of this section.

Existing buildings housing existing protective social care homes or facilities established prior to 1972 (see Chapter 11 of the California Fire Code and the California Existing Building Code).

As an alternative to the requirements in Section R301.1, the following standards are permitted subject to the limitations of this code and the limitations therein. Where engineered design is used in conjunction with these standards, the design shall comply with the California Building Code.

  1. AF&PAWood Frame Construction Manual (WFCM).
  2. AISIStandard for Cold-Formed Steel Framing—Prescriptive Method for One- and Two-Family Dwellings (AISI S230).
  3. ICCStandard on the Design and Construction of Log Structures (ICC 400).

The purpose of this subsection is to permit alternatives that provide minimum protection of life, limb, health, property, safety and welfare of the general public and the owners and occupants of limited-density owner-built rural dwellings as defined in Chapter 2 of this code. For additional information see Chapter 1, Subchapter 1, Article 8, of Title 25, California Code of Regulations, commencing with Section 74.

To meet compliance with the requirements of this code, provisions of Section R301.1.1.1, Items 1 though 5 may be utilized for limited-density owner-built rural dwellings when the materials, methods of construction, or appliances are determined appropriate or suitable for their intended purpose by the local enforcing agency.

  1. A limited-density owner-built rural dwelling may be of any type of construction which will provide for a sound structural condition. Structural hazards which result in an unsound condition and which may constitute a substandard building are delineated in Section 17920.3 of the Health and Safety Code.
  2. There shall be no requirements for room dimensions as required in Chapter 3, provided there is adequate light and ventilation and means of egress.
  3. There shall be no specified requirement for heating capacity or for temperature maintenance. The use of solid-fuel or solar heating devices shall be deemed as complying with the requirements of Chapter 3. If nonrenewable fuel is used in these dwellings, rooms so heated shall meet current installation standards.
  4. Pier foundations, stone masonry footings and foundations, pressure-treated lumber, poles or equivalent foundation materials or designs may be used provided that bearing is sufficient.
  5. Owner-produced or used materials and appliances may be utilized unless found not to be of sufficient strength or durability to perform the intended function. Owner-produced or used lumber, or shakes and shingles may be utilized unless found to contain dry rot, excessive splitting or other defects obviously rendering the material unfit in strength or durability for the intended purpose.
The requirements of this code are based on platform and balloon-frame construction for light-frame buildings. The requirements for concrete and masonry buildings are based on a balloon framing system. Other framing systems must have equivalent detailing to ensure force transfer, continuity and compatible deformations.
Where a building of otherwise conventional construction contains structural elements exceeding the limits of Section R301 or otherwise not conforming to this code, these elements shall be designed in accordance with accepted engineering practice. The extent of such design need only demonstrate compliance of nonconventional elements with other applicable provisions and shall be compatible with the performance of the conventional framed system. Engineered design in accordance with the California Building Code is permitted for buildings and structures, and parts thereof, included in the scope of this code.

When any portion of any structure deviates from substantial compliance with conventional framing requirements for woodframe construction found in this code, the building official shall require the construction documents to be approved and stamped by a California licensed architect or engineer for that irregular or non-conforming portion of work. Notwithstanding other sections of law, the law establishing these provisions is found in Business and Professions Code Sections 5537 and 6737.1.

The building official shall require construction documents to be approved and stamped by a California licensed architect or engineer for all dwellings of woodframe construction more than two stories and basement in height. Notwithstanding other sections of law, the law establishing these provisions is found in Business and Professions Code Sections 5537 and 6737.1.

The building official shall require floor, wall or roof-ceiling structural elements in dwellings designed of cold-formed steel, concrete, masonry or structural insulated panels prescribed by this code to be approved and stamped by a California licensed architect or engineer. Notwithstanding other sections of law, the law establishing these provisions is found in Business and Professions Code Sections 5537 and 6737.1.

Buildings shall be constructed in accordance with the provisions of this code as limited by the provisions of this section. Additional criteria shall be established by the local jurisdiction and set forth in Table R301.2(1).

TABLE R301.2(1)

CLIMATIC AND GEOGRAPHIC DESIGN CRITERIA

GROUND SNOW LOADWIND DESIGNSEISMIC DESIGN CATEGORYfSUBJECT TO DAMAGE FROMWINTER DESIGN TEMPeICE BARRIER UNDERLAYMENT REQUIREDhFLOOD HAZARDSgAIR FREEZING INDEXiMEAN ANNUAL TEMPj
Speedd (mph)Topographic effectskSpecial wind regionlWindborne debris zonemWeatheringaFrost line depthbTermitec

For SI: 1 pound per square foot = 0.0479 kPa, 1 mile per hour = 0.447 m/s.

  1. Weathering may require a higher strength concrete or grade of masonry than necessary to satisfy the structural requirements of this code. The weathering column shall be filled in with the weathering index, “negligible,” “moderate” or “severe” for concrete as determined from Figure R301.2(3). The grade of masonry units shall be determined from ASTM C34, C55, C62, C73, C90, C129, C145, C216 or C652.
  2. The frost line depth may require deeper footings than indicated in Figure R403.1(1). The jurisdiction shall fill in the frost line depth column with the minimum depth of footing below finish grade.
  3. The jurisdiction shall fill in this part of the table to indicate the need for protection depending on whether there has been a history of local subterranean termite damage.
  4. The jurisdiction shall fill in this part of the table with the wind speed from the basic wind speed map [Figure R301.2(4)A]. Wind exposure category shall be determined on a site-specific basis in accordance with Section R301.2.1.4.
  5. Temperatures shall be permitted to reflect local climates or local weather experience as determined by the building official.
  6. The jurisdiction shall fill in this part of the table with the seismic design category determined from Section R301.2.2.1.
  7. The jurisdiction shall fill in this part of the table with (a) the date of the jurisdiction’s entry into the National Flood Insurance Program (date of adoption of the first code or ordinance for management of flood hazard areas), (b) the date(s) of the Flood Insurance Study and (c) the panel numbers and dates of the currently effective FIRMs and FBFMs or other flood hazard map adopted by the authority having jurisdiction, as amended.
  8. In accordance with Sections R905.1.2, R905.4.3.1, R905.5.3.1, R905.6.3.1, R905.7.3.1 and R905.8.3.1, where there has been a history of local damage from the effects of ice damming, the jurisdiction shall fill in this part of the table with “YES.” Otherwise, the jurisdiction shall fill in this part of the table with “NO.”
  9. The jurisdiction shall fill in this part of the table with the 100-year return period air freezing index (BF-days) from Figure R403.3(2) or from the 100-year (99 percent) value on the National Climatic Data Center data table “Air Freezing Index-USA Method (Base 32°F).”
  10. The jurisdiction shall fill in this part of the table with the mean annual temperature from the National Climatic Data Center data table “Air Freezing Index-USA Method (Base 32°F).”
  11. In accordance with Section R301.2.1.5, where there is local historical data documenting structural damage to buildings due to topographic wind speed-up effects, the jurisdiction shall fill in this part of the table with “YES.” Otherwise, the jurisdiction shall indicate “NO” in this part of the table.
  12. In accordance with Figure R301.2(4)A, where there is local historical data documenting unusual wind conditions, the jurisdiction shall fill in this part of the table with “YES” and identify any specific requirements. Otherwise, the jurisdiction shall indicate “NO” in this part of the table.
  13. In accordance with Section R301.2.1.2.1, the jurisdiction shall indicate the wind-borne debris wind zone(s). Otherwise, the jurisdiction shall indicate “NO” in this part of the table.

TABLE R301.2(2)

COMPONENT AND CLADDING LOADS FOR A BUILDING WITH A MEAN ROOF HEIGHT OF 30 FEET LOCATED IN EXPOSURE B (ASD) (psf)a, b, c, d, e

ZONEEFFECTIVE WIND AREA (feet2)ULTIMATE DESIGN WIND SPEED, VULT (mph)
110115120130140150160170180
Roof 0 to 7 degrees
11010.0-13.010.0-14.010.0-15.010.0-18.010.0-21.09.9-24.011.2-27.012.6-31.014.2-35.0
12010.0-12.010.0-13.010.0-15.010.0-17.010.0-20.09.2-23.010.6-26.011.9-30.013.3-34.1
15010.0-12.010.0-13.010.0-14.010.0-17.010.0-19.08.5-22.010.0-26.010.8-29.012.2-32.9
110010.0-11.010.0-13.010.0-14.010.0-16.010.0-19.07.8-22.010.0-25.010.0-28.011.3-32.0
21010.0-21.010.0-23.010.0-26.010.0-30.010.0-35.09.9-40.011.2-46.012.6-52.014.2-58.7
22010.0-19.010.0-21.010.0-23.010.0-27.010.0-31.09.2-36.010.6-41.011.9-46.013.3-52.4
25010.0-16.010.0-18.010.0-19.010.0-23.010.0-26.08.5-30.010.0-34.010.8-39.012.2-44.1
210010.0-14.010.0-15.010.0-16.010.0-19.010.0-22.07.8-26.010.0-30.010.0-33.011.3-37.9
31010.0-33.010.0-36.010.0-39.010.0-46.010.0-53.09.9-61.011.2-69.012.6-78.014.2-88.3
32010.0-27.010.0-29.010.0-32.010.0-38.010.0-44.09.2-50.010.6-57.011.9-65.013.3-73.1
35010.0-19.010.0-21.010.0-23.010.0-27.010.0-32.08.5-36.010.0-41.010.8-47.012.2-53.1
310010.0-14.010.0-15.010.0-16.010.0-19.010.0-22.07.8-26.010.0-30.010.0-33.011.3-37.9
Roof > 7 to 27 degrees
11010.0-11.010.0-13.010.0-14.010.5-16.012.2-19.014.0-22.015.9-25.017.9-28.020.2-32.0
12010.0-11.010.0-12.010.0-13.010.0-16.011.1-18.012.8-21.014.5-24.016.4-27.018.4-31.1
15010.0-11.010.0-12.010.0-13.010.0-15.010.0-18.011.1-20.012.7-23.014.3-26.016.0-29.9
110010.0-10.010.0-11.010.0-12.010.0-15.010.0-17.09.9-20.011.2-22.012.6-25.014.2-29.0
21010.0-20.010.0-22.010.0-24.010.5-29.012.2-33.014.0-38.015.9-44.017.9-49.020.2-55.8
22010.0-19.010.0-20.010.0-22.010.0-26.011.1-31.012.8-35.014.5-40.016.4-45.018.4-51.2
25010.0-16.010.0-18.010.0-20.010.0-23.010.0-27.011.1-31.012.7-35.014.3-40.016.0-45.4
210010.0-15.010.0-16.010.0-18.010.0-21.010.0-24.09.9-28.011.2-32.012.6-36.014.2-40.9
31010.0-30.010.0-33.010.0-36.010.5-43.012.2-49.014.0-57.015.9-65.017.9-73.020.2-82.4
32010.0-28.010.0-31.010.0-34.010.0-40.011.1-46.012.8-53.014.5-60.016.4-68.018.4-77.0
35010.0-26.010.0-28.010.0-31.010.0-36.010.0-42.011.1-48.012.7-55.014.3-62.016.0-69.9
310010.0-24.010.0-26.010.0-28.010.0-33.010.0-39.09.9-44.011.2-51.012.6-57.014.2-64.6
Roof > 27 to 45 degrees
11011.9-13.013.1-14.014.2-15.016.7-18.019.4-21.022.2-24.025.3-27.028.5-31.032.0-35.0
12011.6-12.012.7-13.013.8-14.016.2-17.018.8-20.021.6-23.024.6-26.027.7-29.031.1-33.2
15011.2-11.012.2-12.013.3-13.015.6-16.018.1-18.020.8-21.023.6-24.026.7-27.029.9-30.8
110010.9-10.011.9-11.012.9-12.015.1-15.017.6-17.020.2-20.022.9-22.025.9-25.029.0-29.0
21011.9-15.013.1-16.014.2-18.016.7-21.019.4-24.022.2-28.025.3-32.028.5-36.032.0-40.9
22011.6-14.012.7-16.013.8-17.016.2-20.018.8-23.021.6-27.024.6-30.027.7-34.031.1-39.1
25011.2-13.012.2-15.013.3-16.015.6-19.018.1-22.020.8-25.023.6-29.026.7-32.029.9-36.8
210010.9-13.011.9-14.012.9-15.015.1-18.017.6-21.020.2-24.022.9-27.025.9-31.029.0-35.0
31011.9-15.013.1-16.014.2-18.016.7-21.019.4-24.022.2-28.025.3-32.028.5-36.032.0-40.9
32011.6-14.012.7-16.013.8-17.016.2-20.018.8-23.021.6-27.024.6-30.027.7-34.031.1-39.1
35011.2-13.012.2-15.013.3-16.015.6-19.018.1-22.020.8-25.023.6-29.026.7-32.029.9-36.8
310010.9-13.011.9-14.012.9-15.015.1-18.017.6-21.020.2-24.022.9-27.025.9-31.029.0-35.0
Wall
41013.1-14.014.3-15.015.5-16.018.2-19.021.2-22.024.3-26.027.7-30.031.2-33.035.0-37.9
42012.5-13.013.6-14.014.8-16.017.4-19.020.2-22.023.2-25.026.4-28.029.7-32.033.4-36.4
45011.7-12.012.8-14.013.9-15.016.3-17.019.0-20.021.7-23.024.7-27.027.9-30.031.3-34.3
410011.1-12.012.1-13.013.2-14.015.5-17.018.0-19.020.6-22.023.5-25.026.5-29.029.832.7
450010.0-10.010.6-11.011.6-12.013.6-15.015.8-17.018.1-20.020.6-22.023.2-25.026.1-29.0
51013.1-17.014.3-19.015.5-20.018.2-24.021.2-28.024.3-32.027.7-37.031.2-41.035.0-46.8
52012.5-16.013.6-17.014.8-19.017.4-22.020.2-26.023.2-30.026.4-34.029.7-39.033.4-43.7
55011.7-14.012.8-16.013.9-17.016.3-20.019.0-23.021.7-27.024.7-31.027.9-35.031.3-39.5
510011.1-13.012.1-14.013.2-16.015.5-19.018.0-22.020.6-25.023.5-28.026.5-32.029.8-36.4
550010.0-10.010.6-11.011.6-12.013.6-15.015.8-17.018.1-20.020.6-22.023.2-25.026.1-29.0

For SI: 1 foot = 304.8 mm, 1 square foot = 0.0929 m2, 1 mile per hour = 0.447 m/s, 1 pound per square foot = 0.0479 kPa.

  1. The effective wind area shall be equal to the span length multiplied by an effective width. This width shall be permitted to be not less than one-third the span length. For cladding fasteners, the effective wind area shall not be greater than the area that is tributary to an individual fastener.
  2. For effective areas between those given, the load shall be interpolated or the load associated with the lower effective area shall be used.
  3. Table values shall be adjusted for height and exposure by multiplying by the adjustment coefficient in Table R301.2(3).
  4. See Figure R301.2(7) for location of zones.
  5. Plus and minus signs signify pressures acting toward and away from the building surfaces.

TABLE R301.2(3)

HEIGHT AND EXPOSURE ADJUSTMENT COEFFICIENTS FOR TABLE R301.2(2)

MEAN ROOF HEIGHTEXPOSURE
BCD
151.001.211.47
201.001.291.55
251.001.351.61
301.001.401.66
351.051.451.70
401.091.491.74
451.121.531.78
501.161.561.81
551.191.591.84
601.221.621.87

For SI: °C = [(°F)-32]/1.8.

FIGURE R301.2(1)

ISOLINES OF THE 971/2 PERCENT WINTER (DECEMBER, JANUARY AND FEBRUARY) DESIGN TEMPERATURES (°F)

FIGURE R301.2(2)

SEISMIC DESIGN CATEGORIES—SITE CLASS D

  1. Alaska and Hawaii are classified as severe and negligible, respectively.
  2. Lines defining areas are approximate only. Local conditions may be more or less severe than indicated by region classification. A severe classification is where weather conditions result in significant snowfall combined with extended periods during which there is little or no natural thawing causing deicing salts to be used extensively.

FIGURE R301.2(3)

WEATHERING PROBABILITY MAP FOR CONCRETEa, b



Notes:

  1. Values are nominal design 3-second gust wind speeds in miles per hour (m/s) at 33 ft (10m) above ground for Exposure C category.
  2. Linear interpolation between contours is permitted.
  3. Islands and coastal areas outside the last contour shall use the last wind speed contour of the coastal area.
  4. Mountainous terrain, gorges, ocean promontories, and special wind regions shall be examined for unusual wind conditions.
  5. Wind speeds correspond to approximately a 7% probability of exceedance in 50 years (Annual Exceedance Probability = 0.00143, MRI = 700 Years).


FIGURE R301.2(4)A

ULTIMATE DESIGN WIND SPEEDS

Notes:

  1. Values are nominal design 3-second gust wind speeds in miles per hour (m/s) at 33 ft (10m) above ground for Exposure C category.
  2. Linear interpolation between contours is permitted.
  3. Islands and coastal areas outside the last contour shall use the last wind speed contour of the coastal area.
  4. Mountainous terrain, gorges, ocean promontories, and special wind regions shall be examined for unusual wind conditions.
  5. Wind speeds correspond to approximately a 7% probability of exceedance in 50 years (Annual Exceedance Probability = 0.00143, MRI = 700 Years).

FIGURE R301.2(4)B

REGIONS WHERE WIND DESIGN IS REQUIRED

For SI: 1 foot = 304.8 mm, 1 pound per square foot = 0.0479 kPa, 1 mile = 1.61 km.

  1. In CS areas, site-specific Case Studies are required to establish ground snow loads. Extreme local variations in ground snow loads in these areas preclude mapping at this scale.
  2. Numbers in parentheses represent the upper elevation limits in feet for the ground snow load values presented below. Site-specific case studies are required to establish ground snow loads at elevations not covered.

For SI: 1 foot = 304.8 mm, 1 pound per square foot = 0.0479 kPa.

FIGURE R301.2(5)

GROUND SNOW LOADS, Pg, FOR THE UNITED STATES (lb/ft2)

Note: Lines defining areas are approximate only. Local conditions may be more or less severe than indicated by the region classification.

FIGURE R301.2(6)

TERMITE INFESTATION PROBABILITY MAP

For SI: 1 foot = 304.8 mm, 1 degree = 0.0175 rad.

Note: a = 4 feet in all cases.

FIGURE R301.2(7)

COMPONENT AND CLADDING PRESSURE ZONES

Buildings and portions thereof shall be constructed in accordance with the wind provisions of this code using the ultimate design wind speed in Table R301.2(1) as determined from Figure R301.2(4)A. The structural provisions of this code for wind loads are not permitted where wind design is required as specified in Section R301.2.1.1. Where different construction methods and structural materials are used for various portions of a building, the applicable requirements of this section for each portion shall apply. Where not otherwise specified, the wind loads listed in Table R301.2(2) adjusted for height and exposure using Table R301.2(3) shall be used to determine design load performance requirements for wall coverings, curtain walls, roof coverings, exterior windows, skylights, garage doors and exterior doors. Asphalt shingles shall be designed for wind speeds in accordance with Section R905.2.4. A continuous load path shall be provided to transmit the applicable uplift forces in Section R802.11.1 from the roof assembly to the foundation.

The wind provisions of this code shall not apply to the design of buildings where wind design is required in accordance with Figure R301.2(4)B.

Exceptions:

  1. For concrete construction, the wind provisions of this code shall apply in accordance with the limitations of Sections R404 and R608.
  2. For structural insulated panels, the wind provisions of this code shall apply in accordance with the limitations of Section R610.
  3. For cold-formed steel light-frame construction, the wind provisions of this code shall apply in accordance with the limitations of Sections R505, R603 and R804.

In regions where wind design is required in accordance with Figure R301.2(4)B, the design of buildings for wind loads shall be in accordance with one or more of the following methods:

  1. AF&PAWood Frame Construction Manual (WFCM).
  2. ICC Standard for Residential Construction in High-Wind Regions (ICC 600).
  3. ASCE Minimum Design Loads for Buildings and Other Structures (ASCE 7).
  4. AISIStandard for Cold-Formed Steel Framing—Prescriptive Method For One- and Two-Family Dwellings (AISI S230).
  5. California Building Code.

The elements of design not addressed by the methods in Items 1 through 5 shall be in accordance with the provisions of this code.

Where ASCE 7 or the California Building Code is used for the design of the building, the wind speed map and exposure category requirements as specified in ASCE 7 and the California Building Code shall be used.

Sunrooms shall comply with AAMA/NPEA/NSA 2100. For the purpose of applying the criteria of AAMA/NPEA/NSA 2100 based on the intended use, sunrooms shall be identified as one of the following categories by the permit applicant, design professional or the property owner or owner’s agent in the construction documents. Component and cladding pressures shall be used for the design of elements that do not qualify as main windforce-resisting systems. Main windforce-resisting system pressures shall be used for the design of elements assigned to provide support and stability for the overall sunroom.

Category I: A thermally isolated sunroom with walls that are open or enclosed with insect screening or 0.5 mm (20 mil) maximum thickness plastic film. The space is nonhabitable and unconditioned.

Category II: A thermally isolated sunroom with enclosed walls. The openings are enclosed with translucent or transparent plastic or glass. The space is nonhabitable and unconditioned.

Category III: A thermally isolated sunroom with enclosed walls. The openings are enclosed with translucent or transparent plastic or glass. The sunroom fenestration complies with additional requirements for air infiltration resistance and water penetration resistance. The space is nonhabitable and unconditioned.

Category IV: A thermally isolated sunroom with enclosed walls. The sunroom is designed to be heated or cooled by a separate temperature control or system and is thermally isolated from the primary structure. The sunroom fenestration complies with additional requirements for water penetration resistance, air infiltration resistance and thermal performance. The space is nonhabitable and conditioned.

Category V: A sunroom with enclosed walls. The sunroom is designed to be heated or cooled and is open to the main structure. The sunroom fenestration complies with additional requirements for water penetration resistance, air infiltration resistance and thermal performance. The space is habitable and conditioned.

Exterior glazing in buildings located in windborne debris regions shall be protected from windborne debris. Glazed opening protection for windborne debris shall meet the requirements of the Large Missile Test of ASTM E1996 and ASTM E1886 as modified in Section 301.2.1.2.1. Garage door glazed opening protection for windborne debris shall meet the requirements of an approved impact-resisting standard or ANSI/DASMA 115.

Exception: Wood structural panels with a thickness of not less than 7/16 inch (11 mm) and a span of not more than 8 feet (2438 mm) shall be permitted for opening protection. Panels shall be precut and attached to the framing surrounding the opening containing the product with the glazed opening. Panels shall be predrilled as required for the anchorage method and shall be secured with the attachment hardware provided. Attachments shall be designed to resist the component and cladding loads determined in accordance with either Table R301.2(2) or ASCE 7, with the permanent corrosion-resistant attachment hardware provided and anchors permanently installed on the building. Attachment in accordance with Table R301.2.1.2 is permitted for buildings with a mean roof height of 45 feet (13, 728 mm) or less where the ultimate design wind speed, Vult, is 180 mph (290 kph) or less.

TABLE R301.2.1.2

WINDBORNE DEBRIS PROTECTION FASTENING SCHEDULE FOR WOOD STRUCTURAL PANELSa, b, c, d

FASTENER TYPEFASTENER SPACING (inches)a, b
Panel span ≤ 4 feet4 feet < panel span ≤ 6 feet6 feet < panel span ≤ 8 feet
No. 8 wood screw based anchor with 2-inch embedment length16108
No. 10 wood screw based anchor with 2-inch embedment length16129
1/4-inch lag screw based anchor with 2-inch embedment length161616

For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound = 4.448 N, 1 mile per hour = 0.447 m/s.

  1. This table is based on 180 mph ultimate design wind speeds, Vult, and a 45-foot mean roof height.
  2. Fasteners shall be installed at opposing ends of the wood structural panel. Fasteners shall be located not less than 1 inch from the edge of the panel.
  3. Anchors shall penetrate through the exterior wall covering with an embedment length of not less than 2 inches into the building frame. Fasteners shall be located not less than 21/2 inches from the edge of concrete block or concrete.
  4. Panels attached to masonry or masonry/stucco shall be attached using vibration-resistant anchors having an ultimate withdrawal capacity of not less than 1,500 pounds.

The text of Section 2.2 of ASTM E1996 shall be substituted as follows:

2.2 ASCE Standard:

ASCE 7-10 American Society of Civil Engineers Minimum Design Loads for Buildings and Other Structures

The text of Section 6.2.2 of ASTM E1996 shall be substituted as follows:

6.2.2 Unless otherwise specified, select the wind zone based on the ultimate design wind speed, Vult, as follows:

6.2.2.1 Wind Zone 1–130 mph ≤ ultimate design wind speed, Vult < 140 mph.

6.2.2.2 Wind Zone 2–140 mph ≤ ultimate design wind speed, Vult < 150 mph at greater than 1 mile (1.6 km) from the coastline. The coastline shall be measured from the mean high water mark.

6.2.2.3 Wind Zone 3–150 mph (58 m/s) ≤ ultimate design wind speed, Vult ≤ 170 mph (76 m/s), or 140 mph (54 m/s) ≤ ultimate design wind speed, Vult ≤ 170 mph (76 m/s) and within 1 mile (1.6 km) of the coastline. The coastline shall be measured from the mean high water mark.

6.2.2.4 Wind Zone 4–ultimate design wind speed, Vult > 170 mph (76 m/s).

Where referenced documents are based on nominal design wind speeds and do not provide the means for conversion between ultimate design wind speeds and nominal design wind speeds, the ultimate design wind speeds, Vult, of Figure R301.2(4)A shall be converted to nominal design wind speeds, Vasd, using Table R301.2.1.3.

TABLE R301.2.1.3

WIND SPEED CONVERSIONSa

Vult110115120130140150160170180190200
Vasd858993101108116124132139147155

For SI: 1 mile per hour = 0.447 m/s.

  1. Linear interpolation is permitted.

For each wind direction considered, an exposure category that adequately reflects the characteristics of ground surface irregularities shall be determined for the site at which the building or structure is to be constructed. For a site located in the transition zone between categories, the category resulting in the largest wind forces shall apply. Account shall be taken of variations in ground surface roughness that arise from natural topography and vegetation as well as from constructed features. For a site where multiple detached one- and two-family dwellings, townhouses or other structures are to be constructed as part of a subdivision or master-planned community, or are otherwise designated as a developed area by the authority having jurisdiction, the exposure category for an individual structure shall be based upon the site conditions that will exist at the time when all adjacent structures on the site have been constructed, provided that their construction is expected to begin within one year of the start of construction for the structure for which the exposure category is determined. For any given wind direction, the exposure in which a specific building or other structure is sited shall be assessed as being one of the following categories:

  1. Exposure B. Urban and suburban areas, wooded areas or other terrain with numerous closely spaced obstructions having the size of single-family dwellings or larger. Exposure B shall be assumed unless the site meets the definition of another type exposure.
  2. Exposure C. Open terrain with scattered obstructions, including surface undulations or other irregularities, having heights generally less than 30 feet (9144 mm) extending more than 1,500 feet (457 m) from the building site in any quadrant. This exposure shall also apply to any building located within Exposure B type terrain where the building is directly adjacent to open areas of Exposure C type terrain in any quadrant for a distance of more than 600 feet (183 m). This category includes flat, open country and grasslands.
  3. Exposure D. Flat, unobstructed areas exposed to wind flowing over open water, smooth mud flats, salt flats and unbroken ice for a distance of not less than 5,000 feet (1524 m). This exposure shall apply only to those buildings and other structures exposed to the wind coming from over the unobstructed area. Exposure D extends downwind from the edge of the unobstructed area a distance of 600 feet (183 m) or 20 times the height of the building or structure, whichever is greater.

In areas designated in Table R301.2(1) as having local historical data documenting structural damage to buildings caused by wind speed-up at isolated hills, ridges and escarpments that are abrupt changes from the general topography of the area, topographic wind effects shall be considered in the design of the building in accordance with Section R301.2.1.5.1 or in accordance with the provisions of ASCE 7. See Figure R301.2.1.5.1(1) for topographic features for wind speed-up effect.

In these designated areas, topographic wind effects shall apply only to buildings sited on the top half of an isolated hill, ridge or escarpment where all of the following conditions exist:

  1. The average slope of the top half of the hill, ridge or escarpment is 10 percent or greater.
  2. The hill, ridge or escarpment is 60 feet (18 288 mm) or greater in height for Exposure B, 30 feet (9144 mm) or greater in height for Exposure C, and 15 feet (4572 mm) or greater in height for Exposure D.
  3. The hill, ridge or escarpment is isolated or unobstructed by other topographic features of similar height in the upwind direction for a distance measured from its high point of 100 times its height or 2 miles (3.2 km), whichever is less. See Figure R301.2.1.5.1(3) for upwind obstruction.
  4. The hill, ridge or escarpment protrudes by a factor of two or more above the height of other upwind topographic features located in any quadrant within a radius of 2 miles (3.2 km) measured from its high point.

As an alternative to the ASCE 7 topographic wind provisions, the provisions of Section R301.2.1.5.1 shall be permitted to be used to design for wind speed-up effects, where required by Section R301.2.1.5.

Structures located on the top half of isolated hills, ridges or escarpments meeting the conditions of Section R301.2.1.5 shall be designed for an increased basic wind speed as determined by Table R301.2.1.5.1. On the high side of an escarpment, the increased basic wind speed shall extend horizontally downwind from the edge of the escarpment 1.5 times the horizontal length of the upwind slope (1.5L) or 6 times the height of the escarpment (6H), whichever is greater. See Figure R301.2.1.5.1(2) for where wind speed increase is applied.

TABLE R301.2.1.5.1

ULTIMATE DESIGN WIND SPEED MODIFICATION FOR TOPOGRAPHIC WIND EFFECTa, b

ULTIMATE DESIGN WIND SPEED FROM FIGURE R301.2(4)A (mph)AVERAGE SLOPE OF THE TOP HALF OF HILL, RIDGE OR ESCARPMENT (percent)
0.100.1250.150.1750.200.230.25
Required ultimate design wind speed-up, modified for topographic wind speed-up (mph)
110132137142147152158162
115138143148154159165169
120144149155160166172176
130156162168174179N/AN/A
140168174181N/AN/AN/AN/A
150180N/AN/AN/AN/AN/AN/A

For SI: 1 mile per hour = 0.447 m/s, 1 foot = 304.8 mm.

  1. Table applies to a feature height of 500 feet or less and dwellings sited a distance equal or greater than half the feature height.
  2. Where the ultimate design wind speed as modified by Table R301.2.1.5.1 equals or exceeds 140 miles per hour, the building shall be considered as “wind design required” in accordance with Section R301.2.1.1.

Note: H/2 determines the measurement point for Lh. L is twice Lh.

FIGURE R301.2.1.5.1(1)

TOPOGRAPHIC FEATURES FOR WIND SPEED-UP EFFECT

FIGURE R301.2.1.5.1(2)

ILLUSTRATION OF WHERE ON A TOPOGRAPHIC FEATURE, WIND SPEED INCREASE IS APPLIED



FIGURE R301.2.1.5.1(3)

UPWIND OBSTRUCTION



The seismic provisions of this code shall apply as follows:

  1. Townhouses in Seismic Design Categories C, D0, D1 and D2.
  2. Detached one- and two-family dwellings in Seismic Design Categories, D0, D1 and D2.
Buildings shall be assigned a seismic design category in accordance with Figure R301.2(2).

The seismic design categories and corresponding short-period design spectral response accelerations, SDS shown in Figure R301.2(2) are based on soil Site Class D, as defined in Section 1613.3.2 of the California Building Code. If soil conditions are other than Site Class D, the short-period design spectral response accelerations, SDS, for a site can be determined in accordance with Section 1613.3 of the California Building Code. The value of SDS determined in accordance with Section 1613.3 of the California Building Code is permitted to be used to set the seismic design category in accordance with Table R301.2.2.1.1, and to interpolate between values in Tables R602.10.3(3), R603.9.2(1) and other seismic design requirements of this code.

TABLE R301.2.2.1.1

SEISMIC DESIGN CATEGORY DETERMINATION

CALCULATED SDSSEISMIC DESIGN CATEGORY
SDS ≤ 0.17gA
0.17g < SDS ≤ 0.33gB
0.33g < SDS ≤ 0.50gC
0.50g < SDS ≤ 0.67gD0
0.67g < SDS ≤ 0.83gD1
0.83g < SDS ≤ 1.25gD2
1.25g < SDSE

Buildings located in Seismic Design Category E in accordance with Figure R301.2(2) are permitted to be reclassified as being in Seismic Design Category D2 provided that one of the following is done:

  1. A more detailed evaluation of the seismic design category is made in accordance with the provisions and maps of the California Building Code. Buildings located in Seismic Design Category E in accordance with Table R301.2.2.1.1, but located in Seismic Design Category D in accordance with the California Building Code, shall be permitted to be designed using the Seismic Design Category D2 requirements of this code.
  2. Buildings located in Seismic Design Category E that conform to the following additional restrictions are permitted to be constructed in accordance with the provisions for Seismic Design Category D2 of this code:

    1. 2.1. All exterior shear wall lines or braced wall panels are in one plane vertically from the foundation to the uppermost story.
    2. 2.2. Floors shall not cantilever past the exterior walls.
    3. 2.3. The building is within the requirements of Section R301.2.2.2.5 for being considered as regular.
Structures assigned to Seismic Design Category C shall conform to the requirements of this section.

Average dead loads shall not exceed 15 pounds per square foot (720 Pa) for the combined roof and ceiling assemblies (on a horizontal projection) or 10 pounds per square foot (480 Pa) for floor assemblies, except as further limited by Section R301.2.2. Dead loads for walls above grade shall not exceed:

  1. Fifteen pounds per square foot (720 Pa) for exterior light-frame wood walls.
  2. Fourteen pounds per square foot (670 Pa) for exterior light-frame cold-formed steel walls.
  3. Ten pounds per square foot (480 Pa) for interior light-frame wood walls.
  4. Five pounds per square foot (240 Pa) for interior light-frame cold-formed steel walls.
  5. Eighty pounds per square foot (3830 Pa) for 8-inch-thick (203 mm) masonry walls.
  6. Eighty-five pounds per square foot (4070 Pa) for 6-inch-thick (152 mm) concrete walls.
  7. Ten pounds per square foot (480 Pa) for SIP walls.

Exceptions:

  1. Roof and ceiling dead loads not exceeding 25 pounds per square foot (1190 Pa) shall be permitted provided that the wall bracing amounts in Section R602.10.3 are increased in accordance with Table R602.10.3(4).
  2. Light-frame walls with stone or masonry veneer shall be permitted in accordance with the provisions of Sections R702.1 and R703.
  3. Fireplaces and chimneys shall be permitted in accordance with Chapter 10.
Anchored stone and masonry veneer shall comply with the requirements of Sections R702.1 and R703.
Masonry construction shall comply with the requirements of Section R606.12.
Detached one- and two-family dwellings with exterior above-grade concrete walls shall comply with the requirements of Section R608, PCA 100 or shall be designed in accordance with ACI 318. Townhouses with above-grade exterior concrete walls shall comply with the requirements of PCA 100 or shall be designed in accordance with ACI 318.

The seismic provisions of this code shall not be used for irregular structures located in Seismic Design Categories C, D0, D1 and D2. Irregular portions of structures shall be designed in accordance with accepted engineering practice to the extent the irregular features affect the performance of the remaining structural system. Where the forces associated with the irregularity are resisted by a structural system designed in accordance with accepted engineering practice, design of the remainder of the building shall be permitted using the provisions of this code. A building or portion of a building shall be considered to be irregular where one or more of the following conditions occur:

  1. Where exterior shear wall lines or braced wall panels are not in one plane vertically from the foundation to the uppermost story in which they are required.

    Exception: For wood light-frame construction, floors with cantilevers or setbacks not exceeding four times the nominal depth of the wood floor joists are permitted to support braced wall panels that are out of plane with braced wall panels below provided that:

    1. Floor joists are nominal 2 inches by 10 inches (51 mm by 254 mm) or larger and spaced not more than 16 inches (406 mm) on center.
    2. The ratio of the back span to the cantilever is not less than 2 to 1.
    3. Floor joists at ends of braced wall panels are doubled.
    4. For wood-frame construction, a continuous rim joist is connected to ends of cantilever joists. When spliced, the rim joists shall be spliced using a galvanized metal tie not less than 0.058 inch (1.5 mm) (16 gage) and 11/2 inches (38 mm) wide fastened with six 16d nails on each side of the splice or a block of the same size as the rim joist of sufficient length to fit securely between the joist space at which the splice occurs fastened with eight 16d nails on each side of the splice; and
    5. Gravity loads carried at the end of cantilevered joists are limited to uniform wall and roof loads and the reactions from headers having a span of 8 feet (2438 mm) or less.
  2. Where a section of floor or roof is not laterally supported by shear walls or braced wall lines on all edges.

    Exception: Portions of floors that do not support shear walls or braced wall panels above, or roofs, shall be permitted to extend not more than 6 feet (1829 mm) beyond a shear wall or braced wall line.

  3. Where the end of a braced wall panel occurs over an opening in the wall below and ends at a horizontal distance greater than 1 foot (305 mm) from the edge of the opening. This provision is applicable to shear walls and braced wall panels offset in plane and to braced wall panels offset out of plane as permitted by the exception to Item 1.

    Exception: For wood light-frame wall construction, one end of a braced wall panel shall be permitted to extend more than 1 foot (305 mm) over an opening not more than 8 feet (2438 mm) in width in the wall below provided that the opening includes a header in accordance with the following:

    1. The building width, loading condition and framing member species limitations of Table R602.7(1) shall apply; and
    2. Not less than one 2 × 12 or two 2 × 10 for an opening not more than 4 feet (1219 mm) wide; or
    3. Not less than two 2 × 12 or three 2 × 10 for an opening not more than 6 feet (1829 mm) in width; or
    4. Not less than three 2 × 12 or four 2 × 10 for an opening not more than 8 feet (2438 mm) in width; and
    5. The entire length of the braced wall panel does not occur over an opening in the wall below.
  4. Where an opening in a floor or roof exceeds the lesser of 12 feet (3658 mm) or 50 percent of the least floor or roof dimension.
  5. Where portions of a floor level are vertically offset.

    Exceptions:

    1. Framing supported directly by continuous foundations at the perimeter of the building.
    2. For wood light-frame construction, floors shall be permitted to be vertically offset when the floor framing is lapped or tied together as required by Section R502.6.1.
  6. Where shear walls and braced wall lines do not occur in two perpendicular directions.
  7. Where stories above grade plane partially or completely braced by wood wall framing in accordance with Section R602 or cold-formed steel wall framing in accordance with Section R603 include masonry or concrete construction. Where this irregularity applies, the entire story shall be designed in accordance with accepted engineering practice.

    Exception: Fireplaces, chimneys and masonry veneer as permitted by this code.

Structures assigned to Seismic Design Categories D0, D1 and D2 shall conform to the requirements for Seismic Design Category C and the additional requirements of this section.
Wood-framed buildings shall be limited to three stories above grade plane or the limits given in Table R602.10.3(3). Cold-formed, steel-framed buildings shall be limited to less than or equal to three stories above grade plane in accordance with AISI S230. Mezzanines as defined in Section R202 that comply with Section R325 shall not be considered as stories. Structural insulated panel buildings shall be limited to two stories above grade plane.
Anchored stone and masonry veneer shall comply with the requirements of Sections R702.1 and R703.
Masonry construction in Seismic Design Categories D0 and D1 shall comply with the requirements of Section R606.12.1. Masonry construction in Seismic Design Category D2 shall comply with the requirements of Section R606.12.4.
Buildings with exterior above-grade concrete walls shall comply with PCA 100 or shall be designed in accordance with ACI 318.
In Seismic Design Categories D0, D1 and D2 in addition to the requirements of this code, cold-formed steel framing shall comply with the requirements of AISI S230.
Masonry chimneys shall be reinforced and anchored to the building in accordance with Sections R1003.3 and R1003.4.
Water heaters shall be anchored against movement and overturning in accordance with the California Plumbing Code.
Buildings in Seismic Design Category E shall be designed to resist seismic loads in accordance with the California Building Code, except where the seismic design category is reclassified to a lower seismic design category in accordance with Section R301.2.2.1. Components of buildings not required to be designed to resist seismic loads shall be constructed in accordance with the provisions of this code.
Wood-framed construction, cold-formed, steel-framed construction and masonry and concrete construction, and structural insulated panel construction in regions with ground snow loads 70 pounds per square foot (3.35 kPa) or less, shall be in accordance with Chapters 5, 6 and 8. Buildings in regions with ground snow loads greater than 70 pounds per square foot (3.35 kPa) shall be designed in accordance with accepted engineering practice.
Buildings and structures constructed in whole or in part in flood hazard areas (including A or V Zones) as established in Table R301.2(1), and substantial improvement and restoration of substantial damage of buildings and structures in flood hazard areas, shall be designed and constructed in accordance with Section R322. Buildings and structures that are located in more than one flood hazard area shall comply with the provisions associated with the most restrictive flood hazard area. Buildings and structures located in whole or in part in identified floodways shall be designed and constructed in accordance with ASCE 24.
As an alternative to the requirements in Section R322, ASCE 24 is permitted subject to the limitations of this code and the limitations therein.

The wind and seismic provisions of this code shall apply to buildings with story heights not exceeding the following:

  1. For wood wall framing, the story height shall not exceed 11 feet 7 inches (3531 mm) and the laterally unsupported bearing wall stud height permitted by Table R602.3(5).
  2. For cold-formed steel wall framing, the story height shall be not more than 11 feet 7 inches (3531 mm) and the unsupported bearing wall stud height shall be not more than 10 feet (3048 mm).
  3. For masonry walls, the story height shall be not more than 13 feet 7 inches (4140 mm) and the bearing wall clear height shall be not greater than 12 feet (3658 mm).

    Exception: An additional 8 feet (2438 mm) of bearing wall clear height is permitted for gable end walls.

  4. For insulating concrete form walls, the maximum story height shall not exceed 11 feet 7 inches (3531 mm) and the maximum unsupported wall height per story as permitted by Section R608 tables shall not exceed 10 feet (3048 mm).
  5. For structural insulated panel (SIP) walls, the story height shall be not greater than 11 feet 7 inches (3531 mm) and the bearing wall height per story as permitted by Section R610 tables shall not exceed 10 feet (3048 mm).

Individual walls or wall studs shall be permitted to exceed these limits as permitted by Chapter 6 provisions, provided that story heights are not exceeded. An engineered design shall be provided for the wall or wall framing members where the limits of Chapter 6 are exceeded. Where the story height limits of this section are exceeded, the design of the building, or the noncompliant portions thereof, to resist wind and seismic loads shall be in accordance with the California Building Code.

The actual weights of materials and construction shall be used for determining dead load with consideration for the dead load of fixed service equipment.

The minimum uniformly distributed live load shall be as provided in Table R301.5.

TABLE R301.5

MINIMUM UNIFORMLY DISTRIBUTED LIVE LOADS (in pounds per square foot)

USELIVE LOAD
Uninhabitable attics without storageb10
Uninhabitable attics with limited storageb, g20
Habitable attics and attics served with fixed stairs30
Balconies (exterior) and deckse40
Fire escapes40
Guards and handrailsd200h
Guard in-fill componentsf50h
Passenger vehicle garagesa50a
Rooms other than sleeping rooms40
Sleeping rooms30
Stairs40c

For SI: 1 pound per square foot = 0.0479 kPa, 1 square inch = 645 mm2, 1 pound = 4.45 N.

  1. Elevated garage floors shall be capable of supporting a 2,000-pound load applied over a 20-square-inch area.
  2. Uninhabitable attics without storage are those where the clear height between joists and rafters is not more than 42 inches, or where there are not two or more adjacent trusses with web configurations capable of accommodating an assumed rectangle 42 inches in height by 24 inches in width, or greater, within the plane of the trusses. This live load need not be assumed to act concurrently with any other live load requirements.
  3. Individual stair treads shall be designed for the uniformly distributed live load or a 300-pound concentrated load acting over an area of 4 square inches, whichever produces the greater stresses.
  4. A single concentrated load applied in any direction at any point along the top.
  5. See Section R507.1 for decks attached to exterior walls.
  6. Guard in-fill components (all those except the handrail), balusters and panel fillers shall be designed to withstand a horizontally applied normal load of 50 pounds on an area equal to 1 square foot. This load need not be assumed to act concurrently with any other live load requirement.
  7. Uninhabitable attics with limited storage are those where the clear height between joists and rafters is 42 inches or greater, or where there are two or more adjacent trusses with web configurations capable of accommodating an assumed rectangle 42 inches in height by 24 inches in width, or greater, within the plane of the trusses.

    The live load need only be applied to those portions of the joists or truss bottom chords where all of the following conditions are met:

    1. The attic area is accessible from an opening not less than 20 inches in width by 30 inches in length that is located where the clear height in the attic is not less than 30 inches.
    2. The slopes of the joists or truss bottom chords are not greater than 2 inches vertical to 12 units horizontal.
    3. Required insulation depth is less than the joist or truss bottom chord member depth.

    The remaining portions of the joists or truss bottom chords shall be designed for a uniformly distributed concurrent live load of not less than 10 pounds per square foot.

  8. Glazing used in handrail assemblies and guards shall be designed with a safety factor of 4. The safety factor shall be applied to each of the concentrated loads applied to the top of the rail, and to the load on the infill components. These loads shall be determined independent of one another, and loads are assumed not to occur with any other live load.

The roof shall be designed for the live load indicated in Table R301.6 or the snow load indicated in Table R301.2(1), whichever is greater.

TABLE R301.6

MINIMUM ROOF LIVE LOADS IN POUNDS-FORCE PER SQUARE FOOT OF HORIZONTAL PROJECTION

ROOF SLOPETRIBUTARY LOADED AREA IN SQUARE FEET FOR ANY STRUCTURAL MEMBER
0 to 200201 to 600Over 600
Flat or rise less than 4 inches per foot (1:3)201612
Rise 4 inches per foot (1:3) to less than 12 inches per foot (1:1)161412
Rise 12 inches per foot (1:1) and greater121212

For SI: 1 square foot = 0.0929 m2, 1 pound per square foot = 0.0479 kPa, 1 inch per foot = 83.3 mm/m.

The allowable deflection of any structural member under the live load listed in Sections R301.5 and R301.6 or wind loads determined by Section R301.2.1 shall not exceed the values in Table R301.7.

TABLE R301.7

ALLOWABLE DEFLECTION OF STRUCTURAL MEMBERSb, c

STRUCTURAL MEMBERALLOWABLE DEFLECTION
Rafters having slopes greater than 3:12 with finished ceiling not attached to raftersL/180
Interior walls and partitionsH/180
FloorsL/360
Ceilings with brittle finishes (including plaster and stucco)L/360
Ceilings with flexible finishes (including gypsum board)L/240
All other structural membersL/240
Exterior walls—wind loadsa with plaster or stucco finishH/360
Exterior walls—wind loadsa with other brittle finishesH/240
Exterior walls—wind loadsa with flexible finishesH/120d
Lintels supporting masonry veneer wallseL/600

Note: L = span length, H = span height.

  1. For the purpose of the determining deflection limits herein, the wind load shall be permitted to be taken as 0.7 times the component and cladding (ASD) loads obtained from Table R301.2(2).
  2. For cantilever members, L shall be taken as twice the length of the cantilever.
  3. For aluminum structural members or panels used in roofs or walls of sunroom additions or patio covers, not supporting edge of glass or sandwich panels, the total load deflection shall not exceed L/60. For continuous aluminum structural members supporting edge of glass, the total load deflection shall not exceed L/175 for each glass lite or L/60 for the entire length of the member, whichever is more stringent. For sandwich panels used in roofs or walls of sunroom additions or patio covers, the total load deflection shall not exceed L/120.
  4. Deflection for exterior walls with interior gypsum board finish shall be limited to an allowable deflection of H/180.
  5. Refer to Section R703.8.2.
For the purposes of this code, dimensions of lumber specified shall be deemed to be nominal dimensions unless specifically designated as actual dimensions.

Construction, projections, openings and penetrations of exterior walls of dwellings and accessory buildings shall comply with Table R302.1(1); or dwellings and accessory buildings equipped throughout with an automatic sprinkler system installed in accordance with Section R313 shall comply with Table R302.1(2).

Exceptions:

  1. Walls, projections, openings or penetrations in walls perpendicular to the line used to determine the fire separation distance.
  2. Walls of dwellings and accessory structures located on the same lot.
  3. Detached tool sheds and storage sheds, playhouses and similar structures exempted from permits are not required to provide wall protection based on location on the lot. Projections beyond the exterior wall shall not extend over the lot line.
  4. Detached garages accessory to a dwelling located within 2 feet (610 mm) of a lot line are permitted to have roof eave projections not exceeding 4 inches (102 mm).
  5. Foundation vents installed in compliance with this code are permitted.

TABLE R302.1(1)

EXTERIOR WALLS

EXTERIOR WALL ELEMENTMINIMUM FIRE-RESISTANCE RATINGMINIMUM FIRE SEPARATION DISTANCE
WallsFire-resistance rated1 hour—tested in accordance with ASTM E119 or UL 263 with exposure from both sides< 5 feet
Not fire-resistance rated0 hours≥ 5 feet
ProjectionsNot allowedN/A< 2 feet
Fire-resistance rated1 hour on the undersidea, b≥ 2 feet to < 5 feet
Not fire-resistance rated0 hours≥ 5 feet
Openings in wallsNot allowedN/A< 3 feet
25% maximum of wall area0 hours3 feet
Unlimited0 hours5 feet
PenetrationsAllComply with Section R302.4< 3 feet
None required3 feet

For SI: 1 foot = 304.8 mm.

N/A = Not Applicable.

  1. Roof eave fire-resistance rating shall be permitted to be reduced to 0 hours on the underside of the eave if fireblocking is provided from the wall top plate to the underside of the roof sheathing.
  2. Roof eave fire-resistance rating shall be permitted to be reduced to 0 hours on the underside of the eave provided that gable vent openings are not installed.

TABLE R302.1(2)

EXTERIOR WALLSDWELLINGS AND ACCESSORY BUILDINGS WITH AUTOMATIC RESIDENTIAL FIRE SPRINKLER PROTECTION

EXTERIOR WALL ELEMENTMINIMUM FIRE-RESISTANCE RATINGMINIMUM FIRE SEPARATION DISTANCE
WallsFire-resistance rated1 hour—tested in accordance with ASTM E119 or UL 263 with exposure from the outside0 feet
Not fire-resistance rated0 hours3 feeta
ProjectionsNot allowedN/A< 2 feet
Fire-resistance rated1 hour on the undersideb, c2 feeta
Not fire-resistance rated0 hours3 feet
Openings in wallsNot allowedN/A< 3 feet
Unlimited0 hours3 feeta
PenetrationsAllComply with Section R302.4< 3 feet
None required3 feeta

For SI: 1 foot = 304.8 mm.

N/A = Not Applicable

  1. For residential subdivisions where all dwellings are equipped throughout with an automatic sprinkler system installed in accordance with Section R313, the fire separation distance for nonrated exterior walls and rated projections shall be permitted to be reduced to 0 feet, and unlimited unprotected openings and penetrations shall be permitted, where the adjoining lot provides an open setback yard that is 6 feet or more in width on the opposite side of the property line.
  2. The roof eave fire-resistance rating shall be permitted to be reduced to 0 hours on the underside of the eave if fireblocking is provided from the wall top plate to the underside of the roof sheathing.
  3. The roof eave fire-resistance rating shall be permitted to be reduced to 0 hours on the underside of the eave provided that gable vent openings are not installed.

Common walls separating townhouses shall be assigned a fire-resistance rating in accordance with Section R302.2, Item 1 or 2. The common wall shared by two townhouses shall be constructed without plumbing or mechanical equipment, ducts or vents in the cavity of the common wall. The wall shall be rated for fire exposure from both sides and shall extend to and be tight against exterior walls and the underside of the roof sheathing. Electrical installations shall be in accordance with the California Electrical Code. Penetrations of the membrane of common walls for electrical outlet boxes shall be in accordance with Section R302.4.

  1. Where a fire sprinkler system in accordance with Section R313 is provided, the common wall shall be not less than a 1-hour fire-resistance-rated wall assembly tested in accordance with ASTM E119 or UL 263.
  2. Where a fire sprinkler system in accordance with Section R313 is not provided, the common wall shall be not less than a 2-hour fire-resistance-rated wall assembly tested in accordance with ASTM E119 or UL 263.
The fire-resistance-rated wall or assembly separating townhouses shall be continuous from the foundation to the underside of the roof sheathing, deck or slab. The fire-resistance rating shall extend the full length of the wall or assembly, including wall extensions through and separating attached enclosed accessory structures.

Parapets constructed in accordance with Section R302.2.3 shall be constructed for townhouses as an extension of exterior walls or common walls in accordance with the following:

  1. Where roof surfaces adjacent to the wall or walls are at the same elevation, the parapet shall extend not less than 30 inches (762 mm) above the roof surfaces.
  2. Where roof surfaces adjacent to the wall or walls are at different elevations and the higher roof is not more than 30 inches (762 mm) above the lower roof, the parapet shall extend not less than 30 inches (762 mm) above the lower roof surface.

    Exception: A parapet is not required in the preceding two cases where the roof covering complies with a minimum Class C rating as tested in accordance with ASTM E108 or UL 790 and the roof decking or sheathing is of noncombustible materials or approved fire-retardant-treated wood for a distance of 4 feet (1219 mm) on each side of the wall or walls, or one layer of 5/8-inch (15.9 mm) Type X gypsum board is installed directly beneath the roof decking or sheathing, supported by not less than nominal 2-inch (51 mm) ledgers attached to the sides of the roof framing members, for a distance of not less than 4 feet (1219 mm) on each side of the wall or walls and any openings or penetrations in the roof are not within 4 feet (1219 mm) of the common walls.

  3. A parapet is not required where roof surfaces adjacent to the wall or walls are at different elevations and the higher roof is more than 30 inches (762 mm) above the lower roof. The common wall construction from the lower roof to the underside of the higher roof deck shall have not less than a 1-hour fire-resistance rating. The wall shall be rated for exposure from both sides.
Parapets shall have the same fire-resistance rating as that required for the supporting wall or walls. On any side adjacent to a roof surface, the parapet shall have noncombustible faces for the uppermost 18 inches (457 mm), to include counterflashing and coping materials. Where the roof slopes toward a parapet at slopes greater than 2 units vertical in 12 units horizontal (16.7-percent slope), the parapet shall extend to the same height as any portion of the roof within a distance of 3 feet (914 mm), and the height shall be not less than 30 inches (762 mm).

Each individual townhouse shall be structurally independent.

Exceptions:

  1. Foundations supporting exterior walls or common walls.
  2. Structural roof and wall sheathing from each unit fastened to the common wall framing.
  3. Nonstructural wall and roof coverings.
  4. Flashing at termination of roof covering over common wall.
  5. Townhouses separated by a common wall as provided in Section R302.2, Item 1 or 2.

Dwelling units in two-family dwellings shall be separated from each other by wall and floor assemblies having not less than a 1-hour fire-resistance rating where tested in accordance with ASTM E119 or UL 263. Fire-resistance-rated floor/ceiling and wall assemblies shall extend to and be tight against the exterior wall, and wall assemblies shall extend from the foundation to the underside of the roof sheathing.

Exceptions:

  1. A fire-resistance rating of 1/2 hour shall be permitted in buildings equipped throughout with an automatic sprinkler system installed in accordance with NFPA 13.
  2. Wall assemblies need not extend through attic spaces where the ceiling is protected by not less than 5/8-inch (15.9 mm) Type X gypsum board, an attic draft stop constructed as specified in Section R302.12.1 is provided above and along the wall assembly separating the dwellings and the structural framing supporting the ceiling is protected by not less than 1/2-inch (12.7 mm) gypsum board or equivalent.
Where floor assemblies are required to be fire-resistance rated by Section R302.3, the supporting construction of such assemblies shall have an equal or greater fire-resistance rating.
Penetrations of wall or floor-ceiling assemblies required to be fire-resistance rated in accordance with Section R302.2 or R302.3 shall be protected in accordance with this section.

Through penetrations of fire-resistance-rated wall or floor assemblies shall comply with Section R302.4.1.1 or R302.4.1.2.

Exception: Where the penetrating items are steel, ferrous or copper pipes, tubes or conduits, the annular space shall be protected as follows:

  1. In concrete or masonry wall or floor assemblies, concrete, grout or mortar shall be permitted where installed to the full thickness of the wall or floor assembly or the thickness required to maintain the fire-resistance rating, provided that both of the following are complied with:

    1. 1.1. The nominal diameter of the penetrating item is not more than 6 inches (152 mm).
    2. 1.2. The area of the opening through the wall does not exceed 144 square inches (92 900 mm2).
  2. The material used to fill the annular space shall prevent the passage of flame and hot gases sufficient to ignite cotton waste where subjected to ASTM E119 or UL 263 time temperature fire conditions under a positive pressure differential of not less than 0.01 inch of water (3 Pa) at the location of the penetration for the time period equivalent to the fire-resistance rating of the construction penetrated.
Penetrations shall be installed as tested in the approved fire-resistance-rated assembly.
Penetrations shall be protected by an approved penetration firestop system installed as tested in accordance with ASTM E814 or UL 1479, with a positive pressure differential of not less than 0.01 inch of water (3 Pa) and shall have an F rating of not less than the required fire-resistance rating of the wall or floor-ceiling assembly penetrated.

Membrane penetrations shall comply with Section R302.4.1. Where walls are required to have a fire-resistance rating, recessed fixtures shall be installed so that the required fire-resistance rating will not be reduced.

Exceptions:

  1. Membrane penetrations of not more than 2-hour fire-resistance-rated walls and partitions by steel electrical boxes that do not exceed 16 square inches (0.0103 m2) in area provided that the aggregate area of the openings through the membrane does not exceed 100 square inches (0.0645 m2) in any 100 square feet (9.29 m2) of wall area. The annular space between the wall membrane and the box shall not exceed 1/8 inch (3.1 mm). Such boxes on opposite sides of the wall shall be separated by one of the following:

    1. 1.1. By a horizontal distance of not less than 24 inches (610 mm) where the wall or partition is constructed with individual noncommunicating stud cavities.
    2. 1.2. By a horizontal distance of not less than the depth of the wall cavity where the wall cavity is filled with cellulose loose-fill, rockwool or slag mineral wool insulation.
    3. 1.3. By solid fireblocking in accordance with Section R302.11.
    4. 1.4. By protecting both boxes with listed putty pads.
    5. 1.5. By other listed materials and methods.
  2. Membrane penetrations by listed electrical boxes of any materials provided that the boxes have been tested for use in fire-resistance-rated assemblies and are installed in accordance with the instructions included in the listing. The annular space between the wall membrane and the box shall not exceed 1/8 inch (3.1 mm) unless listed otherwise. Such boxes on opposite sides of the wall shall be separated by one of the following:

    1. 2.1. By the horizontal distance specified in the listing of the electrical boxes.
    2. 2.2. By solid fireblocking in accordance with Section R302.11.
    3. 2.3. By protecting both boxes with listed putty pads.
    4. 2.4. By other listed materials and methods.
  3. The annular space created by the penetration of a fire sprinkler provided that it is covered by a metal escutcheon plate.
Openings and penetrations through the walls or ceilings separating the dwelling from the garage shall be in accordance with Sections R302.5.1 through R302.5.3.

Openings from a private garage directly into a room used for sleeping purposes shall not be permitted. Other openings between the garage and residence shall be equipped with solid wood doors not less than 13/8 inches (35 mm) in thickness, solid or honeycomb-core steel doors not less than 13/8 inches (35 mm) thick, or 20-minute fire-rated doors, equipped with a self-closing and self-latching device.

Exception: Where the residence and the private garage are protected by an automatic residential fire sprinkler system in accordance with Sections R309.6 and R313, other door openings between the private garage and the residence need only be self-closing and self-latching. This exception shall not apply to rooms used for sleeping purposes.

Ducts in the garage and ducts penetrating the walls or ceilings separating the dwelling from the garage shall be constructed of a minimum No. 26 gage (0.48 mm) sheet steel or other approved material and shall not have openings into the garage.
Penetrations through the separation required in Section R302.6 shall be protected as required by Section R302.11, Item 4.

The garage and/or carport shall be separated as required by Table R302.6. Openings in garage walls shall comply with Section R302.5. Attachment of gypsum board shall comply with Table R702.3.5. The wall separation provisions of Table R302.6 shall not apply to garage walls that are perpendicular to the adjacent dwelling unit wall. A separation is not required between the dwelling unit and a carport, provided the carport is entirely open on two or more sides and there are not enclosed areas above.

TABLE R302.6

DWELLING-GARAGE AND/OR CARPORT SEPARATION

SEPARATIONMATERIAL
From the residence and atticsNot less than 1/2-inch gypsum board or equivalent applied to the garage side
From habitable rooms above the garage or carportNot less than 5/8-inch Type X gypsum board or equivalent
Structure(s) supporting floor/ceiling assemblies used for separation required by this sectionNot less than 1/2-inch gypsum board or equivalent
Garages located less than 3 feet from a dwelling unit on the same lotNot less than 1/2-inch gypsum board or equivalent applied to the interior side of exterior walls that are within this area

For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm.

Enclosed accessible space under stairs shall have walls, under-stair surface and any soffits protected on the enclosed side with 1/2-inch (12.7 mm) gypsum board.
For requirements for foam plastics, see Section R316.
Flame spread and smoke developed indexes for wall and ceiling finishes shall be in accordance with Sections R302.9.1 through R302.9.4.

Wall and ceiling finishes shall have a flame spread index of not greater than 200.

Exception: Flame spread index requirements for finishes shall not apply to trim defined as picture molds, chair rails, baseboards and handrails; to doors and windows or their frames; or to materials that are less than 1/28 inch (0.91 mm) in thickness cemented to the surface of walls or ceilings if these materials exhibit flame spread index values not greater than those of paper of this thickness cemented to a noncombustible backing.

Wall and ceiling finishes shall have a smoke-developed index of not greater than 450.
Tests shall be made in accordance with ASTM E84 or UL 723.

As an alternative to having a flame spread index of not greater than 200 and a smoke-developed index of not greater than 450 where tested in accordance with ASTM E84 or UL 723, wall and ceiling finishes shall be permitted to be tested in accordance with NFPA 286. Materials tested in accordance with NFPA 286 shall meet the following criteria:

The interior finish shall comply with the following:

  1. During the 40 kW exposure, flames shall not spread to the ceiling.
  2. The flame shall not spread to the outer extremity of the sample on any wall or ceiling.
  3. Flashover, as defined in NFPA 286, shall not occur.
  4. The peak heat release rate throughout the test shall not exceed 800 kW.
  5. The total smoke released throughout the test shall not exceed 1,000 m2.

Interior finish materials regulated by this chapter shall be applied or otherwise fastened in such a manner that such materials will not readily become detached where subjected to room temperatures of 200°F (93°C) for not less than 30 minutes.

Flame spread and smoke-developed index for insulation shall be in accordance with Sections R302.10.1 through R302.10.5.

Insulation materials, including facings, such as vapor retarders and vapor-permeable membranes installed within floor-ceiling assemblies, roof-ceiling assemblies, wall assemblies, crawl spaces and attics shall have a flame spread index not to exceed 25 with an accompanying smoke-developed index not to exceed 450 where tested in accordance with ASTM E84 or UL 723.

Exceptions:

  1. Where such materials are installed in concealed spaces, the flame spread index and smoke-developed index limitations do not apply to the facings, provided that the facing is installed in substantial contact with the unexposed surface of the ceiling, floor or wall finish.
  2. Cellulose fiber loose-fill insulation, that is not spray applied, complying with the requirements of Section R302.10.3, shall not be required to meet a flame spread index requirement but shall be required to meet a smoke-developed index of not more than 450 where tested in accordance with CAN/ULC S102.2.
  3. Foam plastic insulation shall comply with Section R316.

Loose-fill insulation materials that cannot be mounted in the ASTM E84 or UL 723 apparatus without a screen or artificial supports shall comply with the flame spread and smoke-developed limits of Section R302.10.1 where tested in accordance with CAN/ULC S102.2.

Exception: Cellulosic fiber loose-fill insulation shall not be required to be tested in accordance with CAN/ULC S102.2, provided such insulation complies with the requirements of Sections R302.10.1 and R302.10.3.

Cellulosic fiber loose-fill insulation shall comply with CPSC 16 CFR, Parts 1209 and 1404. Each package of such insulating material shall be clearly labeled in accordance with CPSC 16 CFR, Parts 1209 and 1404.
Exposed insulation materials installed on attic floors shall have a critical radiant flux not less than 0.12 watt per square centimeter.
Tests for critical radiant flux shall be made in accordance with ASTM E970.

In combustible construction, fireblocking shall be provided to cut off both vertical and horizontal concealed draft openings and to form an effective fire barrier between stories, and between a top story and the roof space.

Fireblocking shall be provided in wood-framed construction in the following locations:

  1. In concealed spaces of stud walls and partitions, including furred spaces and parallel rows of studs or staggered studs, as follows:

    1. 1.1. Vertically at the ceiling and floor levels.
    2. 1.2. Horizontally at intervals not exceeding 10 feet (3048 mm).
  2. At interconnections between concealed vertical and horizontal spaces such as occur at soffits, drop ceilings and cove ceilings.
  3. In concealed spaces between stair stringers at the top and bottom of the run. Enclosed spaces under stairs shall comply with Section R302.7.
  4. At openings around vents, pipes, ducts, cables and wires at ceiling and floor level, with an approved material to resist the free passage of flame and products of combustion. The material filling this annular space shall not be required to meet the ASTM E136 requirements.
  5. For the fireblocking of chimneys and fireplaces, see Section R1003.19.
  6. Fireblocking of cornices of a two-family dwelling is required at the line of dwelling unit separation.

Except as provided in Section R302.11, Item 4, fireblocking shall consist of the following materials.

  1. Two-inch (51 mm) nominal lumber.
  2. Two thicknesses of 1-inch (25.4 mm) nominal lumber with broken lap joints.
  3. One thickness of 23/32-inch (18.3 mm) wood structural panels with joints backed by 23/32-inch (18.3 mm) wood structural panels.
  4. One thickness of 3/4-inch (19.1 mm) particleboard with joints backed by 3/4-inch (19.1 mm) particleboard.
  5. One-half-inch (12.7 mm) gypsum board.
  6. One-quarter-inch (6.4 mm) cement-based millboard.
  7. Batts or blankets of mineral wool or glass fiber or other approved materials installed in such a manner as to be securely retained in place.
  8. Cellulose insulation installed as tested in accordance with ASTM E119 or UL 263, for the specific application.
Batts or blankets of mineral or glass fiber or other approved nonrigid materials shall be permitted for compliance with the 10-foot (3048 mm) horizontal fireblocking in walls constructed using parallel rows of studs or staggered studs.
Unfaced fiberglass batt insulation used as fireblocking shall fill the entire cross section of the wall cavity to a height of not less than 16 inches (406 mm) measured vertically. Where piping, conduit or similar obstructions are encountered, the insulation shall be packed tightly around the obstruction.
Loose-fill insulation material shall not be used as a fireblock unless specifically tested in the form and manner intended for use to demonstrate its ability to remain in place and to retard the spread of fire and hot gases.
The integrity of fireblocks shall be maintained.

In combustible construction where there is usable space both above and below the concealed space of a floor-ceiling assembly, draftstops shall be installed so that the area of the concealed space does not exceed 1,000 square feet (92.9 m2). Draftstopping shall divide the concealed space into approximately equal areas. Where the assembly is enclosed by a floor membrane above and a ceiling membrane below, draftstopping shall be provided in floor-ceiling assemblies under the following circumstances:

  1. Ceiling is suspended under the floor framing.
  2. Floor framing is constructed of truss-type open-web or perforated members.
Draftstopping materials shall be not less than 1/2-inch (12.7 mm) gypsum board, 3/8-inch (9.5 mm) wood structural panels or other approved materials adequately supported. Draftstopping shall be installed parallel to the floor framing members unless otherwise approved by the building official. The integrity of the draftstops shall be maintained.

Floor assemblies that are not required elsewhere in this code to be fire-resistance rated, shall be provided with a 1/2-inch (12.7 mm) gypsum wall-board membrane, 5/8-inch (16 mm) wood structural panel membrane, or equivalent on the underside of the floor framing member. Penetrations or openings for ducts, vents, electrical outlets, lighting, devices, luminaires, wires, speakers, drainage, piping and similar openings or penetrations shall be permitted.

Exceptions:

  1. Floor assemblies located directly over a space protected by an automatic sprinkler system in accordance with Section R313, NFPA 13D, or other approved equivalent sprinkler system.
  2. Floor assemblies located directly over a crawl space not intended for storage or fuel-fired appliances.
  3. Portions of floor assemblies shall be permitted to be unprotected where complying with the following:

    1. 3.1. The aggregate area of the unprotected portions does not exceed 80 square feet (7.4 m2) per story.
    2. 3.2. Fireblocking in accordance with Section R302.11.1 is installed along the perimeter of the unprotected portion to separate the unprotected portion from the remainder of the floor assembly.
  4. Wood floor assemblies using dimension lumber or structural composite lumber equal to or greater than 2-inch by 10-inch (50.8 mm by 254 mm) nominal dimension, or other approved floor assemblies demonstrating equivalent fire performance.

Combustible insulation shall be separated not less than 3 inches (76 mm) from recessed luminaires, fan motors and other heat-producing devices.

Exception: Where heat-producing devices are listed for lesser clearances, combustible insulation complying with the listing requirements shall be separated in accordance with the conditions stipulated in the listing.

Recessed luminaires installed in the building envelope shall meet or exceed the requirements specified in the California Energy Code for recessed luminaires installed in insulated ceilings.

Habitable rooms shall have an aggregate glazing area of not less than 8 percent of the floor area of such rooms. Natural ventilation shall be through windows, skylights, doors, louvers or other approved openings to the outdoor air. Such openings shall be provided with ready access or shall otherwise be readily controllable by the building occupants. The openable area to the outdoors shall be not less than 4 percent of the floor area being ventilated.

Exceptions:

  1. The glazed areas need not be openable where the opening is not required by Section R310 and a whole-house mechanical ventilation system is installed in accordance with the California Mechanical Code.
  2. The glazed areas need not be installed in rooms where Exception 1 is satisfied and artificial light is provided that is capable of producing an average illumination of 6 footcandles (65 lux) over the area of the room at a height of 30 inches (762 mm) above the floor level.
  3. Use of sunroom and patio covers, as defined in Section R202, shall be permitted for natural ventilation if in excess of 40 percent of the exterior sunroom walls are open, or are enclosed only by insect screening.
  4. The windows, doors, louvers and other approved closeable openings not required by Section R310 may open into a passive solar energy collector for ventilation required by this section. The area of ventilation openings to the outside of the passive solar energy collector shall be increased to compensate for the openings required by the interior space.
  5. Glazed openings may open into a passive solar energy collector provided the area of exterior glazed opening(s) into the passive solar energy collector is increased to compensate for the area required by the interior space.

For the purpose of determining light and ventilation requirements, any room shall be considered to be a portion of an adjoining room where not less than one-half of the area of the common wall is open and unobstructed and provides an opening of not less than one-tenth of the floor area of the interior room and not less than 25 square feet (2.3 m2).

Exception: Openings required for light or ventilation shall be permitted to open into a sunroom with thermal isolation or a patio cover, provided that there is an openable area between the adjoining room and the sunroom or patio cover of not less than one-tenth of the floor area of the interior room and not less than 20 square feet (2 m2). The minimum openable area to the outdoors shall be based upon the total floor area being ventilated.

Bathrooms, water closet compartments and other similar rooms shall be provided with aggregate glazing area in windows of not less than 3 square feet (0.3 m2), one-half of which must be openable.

Exception: The glazed areas shall not be required where artificial light and a local exhaust system are provided. The minimum local exhaust rates shall be 50 cubic feet per minute (25 L/s) for intermittent ventilation or 20 cubic feet per minute (10 L/s) for continuous ventilation in accordance with the California Mechanical Code, Chapter 4. Exhaust air from the space shall be exhausted directly to the outdoors.

Each bathroom containing a bathtub, shower or tub/shower combination shall be mechanically ventilated for purposes of humidity control in accordance with the California Mechanical Code, Chapter 4; and the California Green Building Standards Code, Chapter 4, Division 4.5.

Note: Window operation is not a permissible method of providing bathroom exhaust for humidity control.

Ventilation air rates shall be in compliance with the California Mechanical Code.

Outdoor intake and exhaust openings shall be located in accordance with Sections R303.5.1 and R303.5.2.

Mechanical and gravity outdoor air intake openings shall be located not less than 10 feet (3048 mm) from any hazardous or noxious contaminant, such as vents, chimneys, plumbing vents, streets, alleys, parking lots and loading docks.

For the purpose of this section, the exhaust from dwelling unit toilet rooms, bathrooms and kitchens shall not be considered as hazardous or noxious.

Exceptions:

  1. The 10-foot (3048 mm) separation is not required where the intake opening is located 3 feet (914 mm) or greater below the contaminant source.
  2. Vents and chimneys serving fuel-burning appliances shall be terminated in accordance with the applicable provisions of Chapters 18 and 24.
  3. Clothes dryer exhaust ducts shall be terminated in accordance with Section M1502.3.
Exhaust air shall not be directed onto walkways.
Air exhaust and intake openings that terminate outdoors shall be protected with corrosion-resistant screens, louvers or grilles having an opening size of not less than 1/4 inch (6 mm) and a maximum opening size of 1/2 inch (13 mm), in any dimension. Openings shall be protected against local weather conditions. Outdoor air exhaust and intake openings shall meet the provisions for exterior wall opening protectives in accordance with this code.

Interior stairways shall be provided with an artificial light source to illuminate the landings and treads. The light source shall be capable of illuminating treads and landings to levels of not less than 1 foot-candle (11 lux) as measured at the center of treads and landings. There shall be a wall switch at each floor level to control the light source where the stairway has six or more risers.

Exception: A switch is not required where remote, central or automatic control of lighting is provided.

Exterior stairways shall be provided with an artificial light source located at the top landing of the stairway. Exterior stairways providing access to a basement from the outdoor grade level shall be provided with an artificial light source located at the bottom landing of the stairway.
Required glazed openings shall be permitted to open into sunroom additions or patio covers that abut a street, yard or court if in excess of 40 percent of the exterior sunroom walls are open, or are enclosed only by insect screening, and the ceiling height of the sunroom is not less than 7 feet (2134 mm).

When a passive solar energy collector is designed as a conditioned area it shall comply with the California Energy Code. Nonconditioned passive solar energy collectors are exempt from the California Energy Code.

Where the winter design temperature in Table R301.2(1) is below 60°F (16°C), every dwelling unit shall be provided with heating facilities capable of maintaining a room temperature of not less than 68°F (20°C) at a point 3 feet (914 mm) above the floor and 2 feet (610 mm) from exterior walls in habitable rooms at the design temperature. The installation of one or more portable space heaters shall not be used to achieve compliance with this section.

Note: See Section R301.1.1.1 for limited-density owner-built rural dwellings.

Habitable rooms shall have a floor area of not less than 70 square feet (6.5 m2).

Exceptions: Kitchens.

Habitable rooms shall be not less than 7 feet (2134 mm) in any horizontal dimension.

Exceptions:

  1. Kitchens.
  2. Limited-density owner-built rural dwellings. See Section R301.1.1.1.
Portions of a room with a sloping ceiling measuring less than 5 feet (1524 mm) or a furred ceiling measuring less than 7 feet (2134 mm) from the finished floor to the finished ceiling shall not be considered as contributing to the minimum required habitable area for that room.

(HCD 1) Unless modified by local ordinance pursuant to Health and Safety Code Section 17958.1, efficiency dwelling units shall comply with the following:

  1. The unit shall have a living room of not less than 220 square feet (20.4 m2) of floor area. An additional 100 square feet (9.3 m2) of floor area shall be provided for each occupant of such unit in excess of two.
  2. The unit shall be provided with a separate closet.
  3. The unit shall be provided with a kitchen sink, cooking appliance and refrigeration facilities, each having a clear working space of not less than 30 inches (762 mm) in front. Light and ventilation conforming to this code shall be provided.
  4. The unit shall be provided with a separate bathroom containing a water closet, lavatory and bathtub or shower.

Habitable space, hallways and portions of basements containing these spaces shall have a ceiling height of not less than 7 feet (2134 mm). Bathrooms, toilet rooms and laundry rooms shall have a ceiling height of not less than 6 feet 8 inches (2032 mm).

Exceptions:

  1. For rooms with sloped ceilings, the required floor area of the room shall have a ceiling height of not less than 5 feet (1524 mm) and not less than 50 percent of the required floor area shall have a ceiling height of not less than 7 feet (2134 mm).
  2. The ceiling height above bathroom and toilet room fixtures shall be such that the fixture is capable of being used for its intended purpose. A shower or tub equipped with a showerhead shall have a ceiling height of not less than 6 feet 8 inches (2032 mm) above an area of not less than 30 inches (762 mm) by 30 inches (762 mm) at the showerhead.
  3. Beams, girders, ducts or other obstructions in basements containing habitable space shall be permitted to project to within 6 feet 4 inches (1931 mm) of the finished floor.

Portions of basements that do not contain habitable space or hallways shall have a ceiling height of not less than 6 feet 8 inches (2032 mm).

Exception: At beams, girders, ducts or other obstructions, the ceiling height shall be not less than 6 feet 4 inches (1931 mm) from the finished floor.

Every dwelling unit shall be provided with a water closet, lavatory, and a bathtub or shower.
Each dwelling unit shall be provided with a kitchen area and every kitchen area shall be provided with a sink.
Plumbing fixtures shall be connected to a sanitary sewer or to an approved private sewage disposal system.
Plumbing fixtures shall be connected to an approved water supply. Kitchen sinks, lavatories, bathtubs, showers, bidets, laundry tubs and washing machine outlets shall be provided with hot and cold water.
Fixtures shall be spaced in accordance with the California Plumbing Code.
Bathtub and shower floors and walls above bathtubs with installed shower heads and in shower compartments shall be finished with a nonabsorbent surface. Such wall surfaces shall extend to a height of not less than 6 feet (1829 mm) above the floor.

Except as indicated in Section R308.1.1 each pane of glazing installed in hazardous locations as defined in Section R308.4 shall be provided with a manufacturer’s designation specifying who applied the designation, designating the type of glass and the safety glazing standard with which it complies, which is visible in the final installation. The designation shall be acid etched, sandblasted, ceramic-fired, laser etched, embossed, or be of a type that once applied cannot be removed without being destroyed. A label shall be permitted in lieu of the manufacturer’s designation.

Exceptions:

  1. For other than tempered glass, manufacturer’s designations are not required provided that the building official approves the use of a certificate, affidavit or other evidence confirming compliance with this code.
  2. Tempered spandrel glass is permitted to be identified by the manufacturer with a removable paper designation.
Multipane assemblies having individual panes not exceeding 1 square foot (0.09 m2) in exposed area shall have not less than one pane in the assembly identified in accordance with Section R308.1. Other panes in the assembly shall be labeled “CPSC 16 CFR 1201” or “ANSI Z97.1” as appropriate.
Regular, float, wired or patterned glass in jalousies and louvered windows shall be not less than nominal 3/16 inch (5 mm) thick and not more than 48 inches (1219 mm) in length. Exposed glass edges shall be smooth.
Wired glass with wire exposed on longitudinal edges shall not be used in jalousies or louvered windows.

Individual glazed areas, including glass mirrors in hazardous locations such as those indicated as defined in Section R308.4, shall pass the test requirements of Section R308.3.1.

Exceptions:

  1. Louvered windows and jalousies shall comply with Section R308.2.
  2. Mirrors and other glass panels mounted or hung on a surface that provides a continuous backing support.
  3. Glass unit masonry complying with Section R607.

Where required by other sections of the code, glazing shall be tested in accordance with CPSC 16 CFR 1201. Glazing shall comply with the test criteria for Category II unless otherwise indicated in Table R308.3.1(1).

Exception: Glazing not in doors or enclosures for hot tubs, whirlpools, saunas, steam rooms, bathtubs and showers shall be permitted to be tested in accordance with ANSI Z97.1. Glazing shall comply with the test criteria for Class A unless indicated in Table R308.3.1(2).

TABLE R308.3.1(1)

MINIMUM CATEGORY CLASSIFICATION OF GLAZING USING CPSC 16 CFR 1201

EXPOSED SURFACE AREA OF ONE SIDE OF ONE LITEGLAZING IN STORM OR COMBINATION DOORS (Category Class)GLAZING IN DOORS (Category Class)GLAZED PANELS REGULATED BY SECTION R308.4.3 (Category Class)GLAZED PANELS REGULATED BY SECTION R308.4.2 (Category Class)GLAZING IN DOORS AND ENCLOSURES REGULATED BY SECTION 308.4.5 (Category Class)SLIDING GLASS DOORS PATIO TYPE (Category Class)
9 square feet or lessIINRIIIII
More than 9 square feetIIIIIIIIIIII

For SI: 1 square foot = 0.0929 m2.

NR = “No Requirement.”

TABLE R308.3.1(2)

MINIMUM CATEGORY CLASSIFICATION OF GLAZING USING ANSI Z97.1

EXPOSED SURFACE AREA OF ONE SIDE OF ONE LITEGLAZED PANELS REGULATED BY SECTION R308.4.3 (Category Class)GLAZED PANELS REGULATED BY SECTION R308.4.2 (Category Class)DOORS AND ENCLOSURES REGULATED BY SECTION R308.4.5a (Category Class)
9 square feet or lessNo requirementBA
More than 9 square feetAAA

For SI: 1 square foot = 0.0929 m2.

  1. Use is permitted only by the exception to Section R308.3.1.
The locations specified in Sections R308.4.1 through R308.4.7 shall be considered to be specific hazardous locations for the purposes of glazing.

Glazing in fixed and operable panels of swinging, sliding and bifold doors shall be considered to be a hazardous location.

Exceptions:

  1. Glazed openings of a size through which a 3-inch-diameter (76 mm) sphere is unable to pass.
  2. Decorative glazing.

Glazing in an individual fixed or operable panel adjacent to a door shall be considered to be a hazardous location where the bottom exposed edge of the glazing is less than 60 inches (1524 mm) above the floor or walking surface and it meets either of the following conditions:

  1. Where the glazing is within 24 inches (610 mm) of either side of the door in the plane of the door in a closed position.
  2. Where the glazing is on a wall perpendicular to the plane of the door in a closed position and within 24 inches (610 mm) of the hinge side of an in-swinging door.

    Exceptions:

    1. Decorative glazing.
    2. Where there is an intervening wall or other permanent barrier between the door and the glazing.
    3. Where access through the door is to a closet or storage area 3 feet (914 mm) or less in depth. Glazing in this application shall comply with Section R308.4.3.
    4. Glazing that is adjacent to the fixed panel of patio doors.

Glazing in an individual fixed or operable panel that meets all of the following conditions shall be considered to be a hazardous location:

  1. The exposed area of an individual pane is larger than 9 square feet (0.836 m2),
  2. The bottom edge of the glazing is less than 18 inches (457 mm) above the floor,
  3. The top edge of the glazing is more than 36 inches (914 mm) above the floor; and
  4. One or more walking surfaces are within 36 inches (914 mm), measured horizontally and in a straight line, of the glazing.

    Exceptions:

    1. Decorative glazing.
    2. Where a horizontal rail is installed on the accessible side(s) of the glazing 34 to 38 inches (864 to 965 mm) above the walking surface. The rail shall be capable of withstanding a horizontal load of 50 pounds per linear foot (730 N/m) without contacting the glass and have a cross-sectional height of not less than 11/2 inches (38 mm).
    3. Outboard panes in insulating glass units and other multiple glazed panels where the bottom edge of the glass is 25 feet (7620 mm) or more above grade, a roof, walking surfaces or other horizontal [within 45 degrees (0.79 rad) of horizontal] surface adjacent to the glass exterior.
Glazing in guards and railings, including structural baluster panels and nonstructural in-fill panels, regardless of area or height above a walking surface shall be considered to be a hazardous location.

Glazing in walls, enclosures or fences containing or facing hot tubs, spas, whirlpools, saunas, steam rooms, bathtubs, showers and indoor or outdoor swimming pools where the bottom exposed edge of the glazing is less than 60 inches (1524 mm) measured vertically above any standing or walking surface shall be considered to be a hazardous location. This shall apply to single glazing and each pane in multiple glazing.

Exception: Glazing that is more than 60 inches (1524 mm), measured horizontally and in a straight line, from the water’s edge of a bathtub, hot tub, spa, whirlpool or swimming pool or from the edge of a shower, sauna or steam room.

Glazing where the bottom exposed edge of the glazing is less than 36 inches (914 mm) above the plane of the adjacent walking surface of stairways, landings between flights of stairs and ramps shall be considered to be a hazardous location.

Exceptions:

  1. Where a rail is installed on the accessible side(s) of the glazing 34 to 38 inches (864 to 965 mm) above the walking surface. The rail shall be capable of withstanding a horizontal load of 50 pounds per linear foot (730 N/m) without contacting the glass and have a cross-sectional height of not less than 11/2 inches (38 mm).
  2. Glazing 36 inches (914 mm) or more measured horizontally from the walking surface.

Glazing adjacent to the landing at the bottom of a stairway where the glazing is less than 36 inches (914 mm) above the landing and within a 60-inch (1524 mm) horizontal arc less than 180 degrees from the bottom tread nosing shall be considered to be a hazardous location.

Exception: The glazing is protected by a guard complying with Section R312 and the plane of the glass is more than 18 inches (457 mm) from the guard.

FIGURE R308.4.7

PROHIBITED GLAZING LOCATIONS AT BOTTOM STAIR LANDINGS

Site-built windows shall comply with Section 2404 of the California Building Code.
Skylights and sloped glazing shall comply with the following sections.

The following terms are defined in Chapter 2:

The following types of glazing shall be permitted to be used:

  1. Laminated glass with not less than a 0.015-inch (0.38 mm) polyvinyl butyral interlayer for glass panes 16 square feet (1.5 m2) or less in area located such that the highest point of the glass is not more than 12 feet (3658 mm) above a walking surface or other accessible area; for higher or larger sizes, the interlayer thickness shall be not less than 0.030 inch (0.76 mm).
  2. Fully tempered glass.
  3. Heat-strengthened glass.
  4. Wired glass.
  5. Approved rigid plastics.
For fully tempered or heat-strengthened glass, a retaining screen meeting the requirements of Section R308.6.7 shall be installed below the glass, except for fully tempered glass that meets either condition listed in Section R308.6.5.
Where the inboard pane is fully tempered, heat-strengthened or wired glass, a retaining screen meeting the requirements of Section R308.6.7 shall be installed below the glass, except for either condition listed in Section R308.6.5. Other panes in the multiple glazing shall be of any type listed in Section R308.6.2.

Screens shall not be required where fully tempered glass is used as single glazing or the inboard pane in multiple glazing and either of the following conditions are met:

  1. Glass area 16 square feet (1.49 m2) or less. Highest point of glass not more than 12 feet (3658 mm) above a walking surface or other accessible area, nominal glass thickness not more than 3/16 inch (4.8 mm), and (for multiple glazing only) the other pane or panes fully tempered, laminated or wired glass.
  2. Glass area greater than 16 square feet (1.49 m2). Glass sloped 30 degrees (0.52 rad) or less from vertical, and highest point of glass not more than 10 feet (3048 mm) above a walking surface or other accessible area.
Any glazing material is permitted to be installed without screening in the sloped areas of greenhouses, provided that the greenhouse height at the ridge does not exceed 20 feet (6096 mm) above grade.
The screen and its fastenings shall be capable of supporting twice the weight of the glazing, be firmly and substantially fastened to the framing members, and have a mesh opening of not more than 1 inch by 1 inch (25 mm by 25 mm).
Unit skylights installed in a roof with a pitch flatter than three units vertical in 12 units horizontal (25-percent slope) shall be mounted on a curb extending not less than 4 inches (102 mm) above the plane of the roof unless otherwise specified in the manufacturer’s installation instructions.
Unit skylights and tubular daylighting devices shall be tested by an approved independent laboratory, and bear a label identifying manufacturer, performance grade rating and approved inspection agency to indicate compliance with the requirements of AAMA/WDMA/CSA 101/I.S.2/A440.

Structural wind load design pressures for glass-glazed unit skylights different than the size tested in accordance with Section R308.6.9 shall be permitted to be different than the design value of the tested unit where determined in accordance with one of the following comparative analysis methods:

  1. Structural wind load design pressures for glass-glazed unit skylights smaller than the size tested in accordance with Section R308.6.9 shall be permitted to be higher than the design value of the tested unit provided that such higher pressures are determined by accepted engineering analysis. Components of the smaller unit shall be the same as those of the tested unit. Such calculated design pressures shall be validated by an additional test of the glass-glazed unit skylight having the highest allowable design pressure.
  2. In accordance with WDMA I.S. 11.

Garage floor surfaces shall be of approved noncombustible material.

The area of floor used for parking of automobiles or other vehicles shall be sloped to facilitate the movement of liquids to a drain or toward the main vehicle entry doorway.

Carports shall be open on not less than two sides. Carport floor surfaces shall be of approved noncombustible material. Carports not open on two or more sides shall be considered to be a garage and shall comply with the provisions of this section for garages.

Exception: Asphalt surfaces shall be permitted at ground level in carports.

The area of floor used for parking of automobiles or other vehicles shall be sloped to facilitate the movement of liquids to a drain or toward the main vehicle entry doorway.

For buildings located in flood hazard areas as established by Table R301.2(1), garage floors shall be:

  1. Elevated to or above the design flood elevation as determined in accordance with Section R322; or
  2. Located below the design flood elevation provided that the floors are at or above grade on not less than one side, are used solely for parking, building access or storage, meet the requirements of Section R322 and are otherwise constructed in accordance with this code.
Automatic garage door openers, if provided, shall be listed and labeled in accordance with UL 325. See Health and Safety Code Sections 19890 and 19891 for additional provisions for residential garage door openers.
Private garages shall be protected by fire sprinklers where the garage wall has been designed based on Table R302.1(2), Footnote a. Sprinklers in garages shall be connected to an automatic sprinkler system that complies with Section R313. Garage sprinklers shall be residential sprinklers or quick-response sprinklers, designed to provide a density of 0.05 gpm/ft2. Garage doors shall not be considered obstructions with respect to sprinkler placement.

Attached garages and carports with habitable space above shall be protected by fire sprinklers in accordance with this section and Section R313. Protection shall be provided in accordance with one of the following:

  1. Residential sprinklers installed in accordance with their listing.
  2. Extended coverage sprinklers discharging water not less than their listed flow rate for Light Hazard in accordance with NFPA 13.
  3. Quick-response spray sprinklers at light hazard spacing in accordance with NFPA 13 designed to discharge at 0.05 gpm/ft2 density (minimum).

The system demand shall be permitted to be limited to the number of sprinklers in the compartment but shall not exceed two sprinklers for hydraulic calculation purposes. Garage doors shall not be considered obstructions and shall be permitted to be ignored for placement and calculation of sprinklers.

Exception:An automatic residential fire sprinkler system shall not be required when additions or alterations are made to existing carports and/or garages that do not have an automatic residential fire sprinkler system installed in accordance with this section.

Every extension garage door spring sold or offered for sale, whether new or sold as a replacement, or installed in any garage or carport which is accessory to a dwelling covered by this code, shall conform to the requirements for garage door springs located in Section 1211 of the California Building Code.

Newly constructed one- and two-family dwellings and town-houses with attached private garages shall comply with EV infrastructure requirements in accordance with the California Green Building Standards Code, Chapter 4, Division 4.1.

Basements, habitable attics and every sleeping room shall have not less than one operable emergency escape and rescue opening. Where basements contain one or more sleeping rooms, an emergency escape and rescue opening shall be required in each sleeping room. Emergency escape and rescue openings shall open directly into a public way, or to a yard or court that opens to a public way.

Exception: Storm shelters and basements used only to house mechanical equipment not exceeding a total floor area of 200 square feet (18.58 m2).

Emergency escape and rescue openings shall be maintained free of any obstructions other than those allowed by this section and shall be operational from the inside of the room without the use of keys, tools or special knowledge. Window opening control devices complying with ASTM F2090 shall be permitted for use on windows serving as a required emergency escape and rescue opening.
Emergency escape and rescue openings shall have minimum dimensions as specified in this section.

Emergency and escape rescue openings shall have a net clear opening of not less than 5.7 square feet (0.530 m2). The net clear opening dimensions required by this section shall be obtained by the normal operation of the emergency escape and rescue opening from the inside. The net clear height opening shall be not less than 24 inches (610 mm) and the net clear width shall be not less than 20 inches (508 mm).

Exception: Grade floor or below grade openings shall have a net clear opening of not less than 5 square feet (0.465 m2).

Where a window is provided as the emergency escape and rescue opening, it shall have the bottom of the clear opening not greater than 44 inches (1118 mm) measured from the floor; where the sill height is below grade, it shall be provided with a window well in accordance with Section R310.2.3.

The horizontal area of the window well shall be not less than 9 square feet (0.9 m2), with a horizontal projection and width of not less than 36 inches (914 mm). The area of the window well shall allow the emergency escape and rescue opening to be fully opened.

Exception: The ladder or steps required by Section R310.2.3.1 shall be permitted to encroach not more than 6 inches (152 mm) into the required dimensions of the window well.

Window wells with a vertical depth greater than 44 inches (1118 mm) shall be equipped with a permanently affixed ladder or steps usable with the window in the fully open position. Ladders or steps required by this section shall not be required to comply with Sections R311.7 and R311.8. Ladders or rungs shall have an inside width of not less than 12 inches (305 mm), shall project not less than 3 inches (76 mm) from the wall and shall be spaced not more than 18 inches (457 mm) on center vertically for the full height of the window well.

Window wells shall be designed for proper drainage by connecting to the building’s foundation drainage system required by Section R405.1 or by an approved alternative method.

Exception: A drainage system for window wells is not required where the foundation is on well-drained soil or sand-gravel mixture soils in accordance with the United Soil Classification System, Group I Soils, as detailed in Table R405.1.

Replacement windows installed in buildings meeting the scope of this code shall be exempt from the maximum sill height requirements of Sections R310.1 and Sections R310.2.1 and R310.2.2, provided the replacement window meets the following conditions:
  1. The replacement window is the manufacturer’s largest standard size window that will fit within the existing frame or existing rough opening. The replacement window is of the same operating style as the existing window or a style that provides for an equal or greater window opening area than the existing window.
  2. The replacement window is not part of a change of occupancy.
Where a door is provided as the required emergency escape and rescue opening, it shall be permitted to be a side-hinged door or a slider. Where the opening is below the adjacent ground elevation, it shall be provided with a bulkhead enclosure.
The minimum net clear height opening for any door that serves as an emergency and escape rescue opening shall be in accordance with Section R310.2.1.
Bulkhead enclosures shall provide direct access from the basement. The bulkhead enclosure shall provide the minimum net clear opening equal to the door in the fully open position.

Bulkhead enclosures shall be designed for proper drainage by connecting to the building’s foundation drainage system required by Section R405.1 or by an approved alternative method.

Exception: A drainage system for bulkhead enclosures is not required where the foundation is on well-drained soil or sand-gravel mixture soils in accordance with the United Soil Classification System, Group I Soils, as detailed in Table R405.1.

Bars, grilles, covers, screens or similar devices are permitted to be placed over emergency escape and rescue openings, bulkhead enclosures, or window wells that serve such openings, provided that the minimum net clear opening size complies with Sections R310.1.1 to R310.2.3, and such devices shall be releasable or removable from the inside without the use of a key, tool, special knowledge or force greater than that required for the normal operation of the escape and rescue opening. The release mechanism shall be maintained operable at all times.

Such bars, grills, grates or any similar devices shall be equipped with an approved exterior release device for use by the fire department only when required by the authority having jurisdiction.

Where security bars (burglar bars) are installed on emergency egress and rescue windows or doors, on or after July 1, 2000, such devices shall comply with California Building Standards Code, Part 12, Chapter 12-3 and other applicable provisions of this code.

Where dwelling additions occur that contain sleeping rooms, an emergency escape and rescue opening shall be provided in each new sleeping room. Where dwelling additions occur that have basements, an emergency escape and rescue opening shall be provided in the new basement.

Exceptions:

  1. An emergency escape and rescue opening is not required in a new basement that contains a sleeping room with an emergency escape and rescue opening.
  2. An emergency escape and rescue opening is not required in a new basement where there is an emergency escape and rescue opening in an existing basement that is accessible from the new basement.

An emergency escape and rescue opening is not required where existing basements undergo alterations or repairs.

Exception: New sleeping rooms created in an existing basement shall be provided with emergency escape and rescue openings in accordance with Section R310.1.

Dwellings shall be provided with a means of egress in accordance with this section. The means of egress shall provide a continuous and unobstructed path of vertical and horizontal egress travel from all portions of the dwelling to the required egress door without requiring travel through a garage. The required egress door shall open directly into a public way or to a yard or court that opens to a public way.
Not less than one egress door shall be provided for each dwelling unit. The egress door shall be side-hinged, and shall provide a clear width of not less than 32 inches (813 mm) where measured between the face of the door and the stop, with the door open 90 degrees (1.57 rad). The clear height of the door opening shall be not less than 78 inches (1981 mm) in height measured from the top of the threshold to the bottom of the stop. Other doors shall not be required to comply with these minimum dimensions. Egress doors shall be readily openable from inside the dwelling without the use of a key or special knowledge or effort.

There shall be a landing or floor on each side of each exterior door. The width of each landing shall be not less than the door served. Every landing shall have a dimension of not less than 36 inches (914 mm) measured in the direction of travel. The slope at exterior landings shall not exceed 1/4 unit vertical in 12 units horizontal (2 percent).

Exception: Exterior balconies less than 60 square feet (5.6 m2) and only accessible from a door are permitted to have a landing less than 36 inches (914 mm) measured in the direction of travel.

Landings or finished floors at the required egress door shall be not more than 11/2 inches (38 mm) lower than the top of the threshold.

Exception: The landing or floor on the exterior side shall be not more than 73/4 inches (196 mm) below the top of the threshold provided the door does not swing over the landing or floor.

Where exterior landings or floors serving the required egress door are not at grade, they shall be provided with access to grade by means of a ramp in accordance with Section R311.8 or a stairway in accordance with Section R311.7.

Doors other than the required egress door shall be provided with landings or floors not more than 73/4 inches (196 mm) below the top of the threshold.

Exception: A top landing is not required where a stairway of not more than two risers is located on the exterior side of the door, provided that the door does not swing over the stairway.

Storm and screen doors shall be permitted to swing over exterior stairs and landings.
Egress from habitable levels including habitable attics and basements not provided with an egress door in accordance with Section R311.2 shall be by one or more ramps in accordance with Section R311.8 or one or more stairways in accordance with Section R311.7 or both. For habitable levels or basements located more than one story above or more than one story below an egress door, the maximum travel distance from any occupied point to a stairway or ramp that provides egress from such habitable level or basement, shall not exceed 50 feet (15 240 mm).
Exterior landings, decks, balconies, stairs and similar facilities shall be positively anchored to the primary structure to resist both vertical and lateral forces or shall be designed to be self-supporting. Attachment shall not be accomplished by use of toe-nails or nails subject to withdrawal.
The width of a hallway shall be not less than 3 feet (914 mm).

Stairways shall be not less than 36 inches (914 mm) in clear width at all points above the permitted handrail height and below the required headroom height. Handrails shall not project more than 41/2 inches (114 mm) on either side of the stairway and the clear width of the stairway at and below the handrail height, including treads and landings, shall be not less than 311/2 inches (787 mm) where a handrail is installed on one side and 27 inches (698 mm) where handrails are provided on both sides.

Exception: The width of spiral stairways shall be in accordance with Section R311.7.10.1.

The headroom in stairways shall be not less than 6 feet 8 inches (2032 mm) measured vertically from the sloped line adjoining the tread nosing or from the floor surface of the landing or platform on that portion of the stairway.

Exceptions:

  1. Where the nosings of treads at the side of a flight extend under the edge of a floor opening through which the stair passes, the floor opening shall be allowed to project horizontally into the required headroom not more than 43/4 inches (121 mm).
  2. The headroom for spiral stairways shall be in accordance with Section R311.7.10.1.
A flight of stairs shall not have a vertical rise larger than 147 inches (3734 mm) between floor levels or landings.
The walkline across winder treads shall be concentric to the curved direction of travel through the turn and located 12 inches (305 mm) from the side where the winders are narrower. The 12-inch (305 mm) dimension shall be measured from the widest point of the clear stair width at the walking surface of the winder. If winders are adjacent within the flight, the point of the widest clear stair width of the adjacent winders shall be used.
Stair treads and risers shall meet the requirements of this section. For the purposes of this section, dimensions and dimensioned surfaces shall be exclusive of carpets, rugs or runners.

The riser height shall be not more than 73/4 inches (196 mm). The riser shall be measured vertically between leading edges of the adjacent treads. The greatest riser height within any flight of stairs shall not exceed the smallest by more than 3/8 inch (9.5 mm). Risers shall be vertical or sloped from the underside of the nosing of the tread above at an angle not more than 30 degrees (0.51 rad) from the vertical. Open risers are permitted provided that the openings located more than 30 inches (762 mm), as measured vertically, to the floor or grade below do not permit the passage of a 4-inch-diameter (102 mm) sphere.

Exceptions:

  1. The opening between adjacent treads is not limited on spiral stairways.
  2. The riser height of spiral stairways shall be in accordance with Section R311.7.10.1.
The tread depth shall be not less than 10 inches (254 mm). The tread depth shall be measured horizontally between the vertical planes of the foremost projection of adjacent treads and at a right angle to the tread’s leading edge. The greatest tread depth within any flight of stairs shall not exceed the smallest by more than 3/8 inch (9.5 mm).

Winder treads shall have a tread depth of not less than 10 inches (254 mm) measured between the vertical planes of the foremost projection of adjacent treads at the intersections with the walkline. Winder treads shall have a tread depth of not less than 6 inches (152 mm) at any point within the clear width of the stair. Within any flight of stairs, the largest winder tread depth at the walkline shall not exceed the smallest winder tread by more than 3/8 inch (9.5 mm). Consistently shaped winders at the walkline shall be allowed within the same flight of stairs as rectangular treads and do not have to be within 3/8 inch (9.5 mm) of the rectangular tread depth.

Exception: The tread depth at spiral stairways shall be in accordance with Section R311.7.10.1.

The radius of curvature at the nosing shall be not greater than 9/16 inch (14 mm). A nosing projection not less than 3/4 inch (19 mm) and not more than 11/4 inches (32 mm) shall be provided on stairways with solid risers. The greatest nosing projection shall not exceed the smallest nosing projection by more than 3/8 inch (9.5 mm) between two stories, including the nosing at the level of floors and landings. Beveling of nosings shall not exceed 1/2 inch (12.7 mm).

Exception: A nosing projection is not required where the tread depth is not less than 11 inches (279 mm).

Plastic composite exterior stair treads shall comply with the provisions of this section and Section R507.3.

There shall be a floor or landing at the top and bottom of each stairway. The width perpendicular to the direction of travel shall be not less than the width of the flight served. Landings of shapes other than square or rectangular shall be permitted provided that the depth at the walk line and the total area is not less than that of a quarter circle with a radius equal to the required landing width. Where the stairway has a straight run, the depth in the direction of travel shall be not less than 36 inches (914 mm).

Exception: A floor or landing is not required at the top of an interior flight of stairs, including stairs in an enclosed garage, provided that a door does not swing over the stairs.

The walking surface of treads and landings of stairways shall be sloped not steeper than one unit vertical in 48 inches horizontal (2-percent slope).
Handrails shall be provided on not less than one side of each continuous run of treads or flight with four or more risers.

Handrail height, measured vertically from the sloped plane adjoining the tread nosing, or finish surface of ramp slope, shall be not less than 34 inches (864 mm) and not more than 38 inches (965 mm).

Exceptions:

  1. The use of a volute, turnout or starting easing shall be allowed over the lowest tread.
  2. Where handrail fittings or bendings are used to provide continuous transition between flights, transitions at winder treads, the transition from handrail to guard, or used at the start of a flight, the handrail height at the fittings or bendings shall be permitted to exceed 38 inches (956 mm).

Handrails for stairways shall be continuous for the full length of the flight, from a point directly above the top riser of the flight to a point directly above the lowest riser of the flight. Handrail ends shall be returned or shall terminate in newel posts or safety terminals. Handrails adjacent to a wall shall have a space of not less than 11/2 inches (38 mm) between the wall and the handrails.

Exceptions:

  1. Handrails shall be permitted to be interrupted by a newel post at the turn.
  2. The use of a volute, turnout, starting easing or starting newel shall be allowed over the lowest tread.

Required handrails shall be of one of the following types or provide equivalent graspability.

  1. Type I. Handrails with a circular cross section shall have an outside diameter of not less than 11/4 inches (32 mm) and not greater than 2 inches (51 mm). If the handrail is not circular, it shall have a perimeter dimension of not less than 4 inches (102 mm) and not greater than 61/4 inches (160 mm) with a cross section of dimension of not more than 21/4 inches (57 mm). Edges shall have a radius of not less than 0.01 inch (0.25 mm).
  2. Type II. Handrails with a perimeter greater than 61/4 inches (160 mm) shall have a graspable finger recess area on both sides of the profile. The finger recess shall begin within a distance of 3/4 inch (19 mm) measured vertically from the tallest portion of the profile and achieve a depth of not less than 5/16 inch (8 mm) within 7/8 inch (22 mm) below the widest portion of the profile. This required depth shall continue for not less than 3/8 inch (10 mm) to a level that is not less than 13/4 inches (45 mm) below the tallest portion of the profile. The width of the handrail above the recess shall be not less than 11/4 inches (32 mm) and not more than 23/4 inches (70 mm). Edges shall have a radius of not less than 0.01 inch (0.25 mm).
Plastic composite exterior handrails shall comply with the requirements of Section R507.3.
Stairways shall be provided with illumination in accordance with Section R303.7.
Spiral stairways and bulkhead enclosure stairways shall comply with the requirements of Section R311.7 except as specified in Sections R311.7.10.1 and R311.7.10.2.
Spiral stairways are permitted, provided that the clear width at and below the handrail is not less than 26 inches (660 mm) and the walkline radius is not greater than 241/2 inches (622 mm). Each tread shall have a depth of not less than 63/4 inches (171 mm) at the walkline. All treads shall be identical, and the rise shall be not more than 91/2 inches (241 mm). Headroom shall be not less than 6 feet 6 inches (1982 mm).
Stairways serving bulkhead enclosures, not part of the required building egress, providing access from the outside grade level to the basement shall be exempt from the requirements of Sections R311.3 and R311.7 where the height from the basement finished floor level to grade adjacent to the stairway is not more than 8 feet (2438 mm) and the grade level opening to the stairway is covered by a bulkhead enclosure with hinged doors or other approved means.
Alternating tread devices shall not be used as an element of a means of egress. Alternating tread devices shall be permitted provided that the required means of egress stairway or ramp serves the same space at each adjoining level or where a means of egress is not required. The clear width at and below the handrails shall be not less than 20 inches (508 mm).
Alternating tread devices shall have a tread depth of not less than 5 inches (127 mm), a projected tread depth of not less than 81/2 inches (216 mm), a tread width of not less than 7 inches (178 mm) and a riser height of not more than 91/2 inches (241 mm). The tread depth shall be measured horizontally between the vertical planes of the foremost projections of adjacent treads. The riser height shall be measured vertically between the leading edges of adjacent treads. The riser height and tread depth provided shall result in an angle of ascent from the horizontal of between 50 and 70 degrees (0.87 and 1.22 rad). The initial tread of the device shall begin at the same elevation as the platform, landing or floor surface.
Handrails shall be provided on both sides of alternating tread devices and shall comply with Sections R311.7.8.2 to R311.7.8.4. Handrail height shall be uniform, not less than 30 inches (762 mm) and not more than 34 inches (864 mm).
Ships ladders shall not be used as an element of a means of egress. Ships ladders shall be permitted provided that a required means of egress stairway or ramp serves the same space at each adjoining level or where a means of egress is not required. The clear width at and below the handrails shall be not less than 20 inches.
Treads shall have a depth of not less than 5 inches (127 mm). The tread shall be projected such that the total of the tread depth plus the nosing projection is not less than 81/2 inches (216 mm). The riser height shall be not more than 91/2 inches (241 mm).
Handrails shall be provided on both sides of ships ladders and shall comply with Sections R311.7.8.2 to R311.7.8.4. Handrail height shall be uniform, not less than 30 inches (762 mm) and not more than 34 inches (864 mm).

Ramps serving the egress door required by Section R311.2 shall have a slope of not more than 1 unit vertical in 12 units horizontal (8.3-percent slope). All other ramps shall have a maximum slope of 1 unit vertical in 8 units horizontal (12.5 percent).

Exception: Where it is technically infeasible to comply because of site constraints, ramps shall have a slope of not more than 1 unit vertical in 8 units horizontal (12.5 percent).

There shall be a floor or landing at the top and bottom of each ramp, where doors open onto ramps, and where ramps change directions. The width of the landing perpendicular to the ramp slope shall be not less than 36 inches (914 mm).
Handrails shall be provided on not less than one side of ramps exceeding a slope of one unit vertical in 12 units horizontal (8.33-percent slope).
Handrail height, measured above the finished surface of the ramp slope, shall be not less than 34 inches (864 mm) and not more than 38 inches (965 mm).
Handrails on ramps shall comply with Section R311.7.8.3.
Handrails where required on ramps shall be continuous for the full length of the ramp. Handrail ends shall be returned or shall terminate in newel posts or safety terminals. Handrails adjacent to a wall shall have a space of not less than 11/2 inches (38 mm) between the wall and the handrails.
Guards shall be provided in accordance with Sections R312.1.1 through R312.1.4.
Guards shall be located along open-sided walking surfaces, including stairs, ramps and landings, that are located more than 30 inches (762 mm) measured vertically to the floor or grade below at any point within 36 inches (914 mm) horizontally to the edge of the open side. Insect screening shall not be considered as a guard.

Required guards at open-sided walking surfaces, including stairs, porches, balconies or landings, shall be not less than 42 inches (1067 mm) in height as measured vertically above the adjacent walking surface or the line connecting the leading edges of the treads.

Exceptions:

  1. Guards on the open sides of stairs shall have a height not less than 34 inches (864 mm) measured vertically from a line connecting the leading edges of the treads.
  2. Where the top of the guard serves as a handrail on the open sides of stairs, the top of the guard shall be not less than 34 inches (864 mm) and not more than 38 inches (965 mm) as measured vertically from a line connecting the leading edges of the treads.

Required guards shall not have openings from the walking surface to the required guard height that allow passage of a sphere 4 inches (102 mm) in diameter.

Exceptions:

  1. The triangular openings at the open side of stair, formed by the riser, tread and bottom rail of a guard, shall not allow passage of a sphere 6 inches (153 mm) in diameter.
  2. Guards on the open side of stairs shall not have openings that allow passage of a sphere 43/8 inches (111 mm) in diameter.
Plastic composite exterior guards shall comply with the requirements of Section R317.4.
Window fall protection shall be provided in accordance with Sections R312.2.1 and R312.2.2.

In dwelling units, where the top of the sill of an operable window opening is located less than 24 inches (610 mm) above the finished floor and greater than 72 inches (1829 mm) above the finished grade or other surface below on the exterior of the building, the operable window shall comply with one of the following:

  1. Operable windows with openings that will not allow a 4-inch-diameter (102 mm) sphere to pass through the opening where the opening is in its largest opened position.
  2. Operable windows that are provided with window fall prevention devices that comply with ASTM F2090.
  3. Operable windows that are provided with window opening control devices that comply with Section R312.2.2.
Window opening control devices shall comply with ASTM F2090. The window opening control device, after operation to release the control device allowing the window to fully open, shall not reduce the net clear opening area of the window unit to less than the area required by Section R310.2.1.

An automatic residential fire sprinkler system shall be installed in townhouses.

Exception: An automatic residential fire sprinkler system shall not be required where additions or alterations are made to existing townhouses that do not have an automatic residential fire sprinkler system installed.

Automatic residential fire sprinkler systems for townhouses shall be designed and installed in accordance with Section R313.3 or NFPA 13D.
An automatic residential fire sprinkler system shall be installed in one- and two-family dwellings.

Exceptions:
  1. An automatic residential fire sprinkler system shall not be required for additions or alterations to existing buildings that are not already provided with an automatic residential sprinkler system.
  2. Accessory Dwelling Unit, provided that all of the following are met:
    1. The unit meets the definition of an Accessory Dwelling Unit as defined in the Government Code Section 65852.2.
    2. The existing primary residence does not have automatic fire sprinklers.
    3. The accessory detached dwelling unit does not exceed 1,200 square feet in size.
    4. The unit is on the same lot as the primary residence.
Automatic residential fire sprinkler systems shall be designed and installed in accordance with Section R313.3 or NFPA 13D.
The design and installation of residential fire sprinkler systems shall be in accordance with NFPA 13D or Section R313.3, which shall be considered equivalent to NFPA 13D. Partial residential sprinkler systems shall be permitted to be installed only in buildings not required to be equipped with a residential sprinkler system. Section R313.3 shall apply to stand-alone and multipurpose wet-pipe sprinkler systems that do not include the use of antifreeze. A multipurpose fire sprinkler system shall supply domestic water to both fire sprinklers and plumbing fixtures. A stand-alone sprinkler system shall be separate and independent from the water distribution system.

A backflow preventer shall not be required to separate a sprinkler system from the water distribution system, provided that:

  1. The system complies with NFPA 13D or Section R313;
  2. Piping materials are suitable for potable water in accordance with the California Plumbing Code; and
  3. The system does not contain antifreeze or have a fire department connection.

Sprinklers shall be installed to protect all areas of a dwelling unit.

Exceptions:

  1. Attics, crawl spaces and normally unoccupied concealed spaces that do not contain fuel-fired appliances do not require sprinklers. In attics, crawl spaces and normally unoccupied concealed spaces that contain fuel-fired equipment, a sprinkler shall be installed above the equipment; however, sprinklers shall not be required in the remainder of the space.
  2. Clothes closets, linen closets and pantries not exceeding 24 square feet (2.2 m2) in area, with the smallest dimension not greater than 3 feet (915 mm) and having wall and ceiling surfaces of gypsum board.
  3. Bathrooms not more than 55 square feet (5.1 m2) in area.
  4. Detached garages; carports with no habitable space above; open attached porches; unheated entry areas, such as mud rooms, that are adjacent to an exterior door; and similar areas.
Sprinklers shall be new listed residential sprinklers and shall be installed in accordance with the sprinkler manufacturer’s installation instructions.
Except as provided for in Section R313.3.2.2, sprinklers shall have a temperature rating of not less than 135°F (57°C) and not more than 170°F (77°C). Sprinklers shall be separated from heat sources as required by the sprinkler manufacturer’s installation instructions.

Sprinklers shall have an intermediate temperature rating not less than 175°F (79°C) and not more than 225°F (107°C) where installed in the following locations:

  1. Directly under skylights, where the sprinkler is exposed to direct sunlight.
  2. In attics.
  3. In concealed spaces located directly beneath a roof.
  4. Within the distance to a heat source as specified in Table R313.3.2.2.

TABLE R313.3.2.2

LOCATIONS WHERE INTERMEDIATE TEMPERATURE SPRINKLERS ARE REQUIRED

HEAT SOURCERANGE OF DISTANCE FROM HEAT SOURCE WITHIN WHICH INTERMEDIATE TEMPERATURE SPRINKLERS ARE REQUIREDa,b (inches)
Fireplace, side of open or recessed fireplace12 to 36
Fireplace, front of recessed fireplace36 to 60
Coal and wood burning stove12 to 42
Kitchen range top9 to 18
Oven9 to 18
Vent connector or chimney connector9 to 18
Heating duct, not insulated9 to 18
Hot water pipe, not insulated6 to 12
Side of ceiling or wall warm air register12 to 24
Front of wall mounted warm air register18 to 36
Water heater, furnace or boiler3 to 6
Luminaire up to 250 watts3 to 6
Luminaire 250 watts up to 499 watts6 to 12

For SI: 1 inch = 25.4 mm.

  1. Sprinklers shall not be located at distances less than the minimum table distance unless the sprinkler listing allows a lesser distance.
  2. Distances shall be measured in a straight line from the nearest edge of the heat source to the nearest edge of the sprinkler.
Piping shall be protected from freezing as required by the California Plumbing Code. Where sprinklers are required in areas that are subject to freezing, dry-sidewall or dry-pendent sprinklers extending from a nonfreezing area into a freezing area shall be installed. Where fire sprinkler piping cannot be adequately protected against freezing, the system shall be designed and installed in accordance with NFPA 13D.
Sprinkler coverage requirements and sprinkler obstruction requirements shall be in accordance with Sections R313.3.2.4.1 and R313.3.2.4.2.
The area of coverage of a single sprinkler shall not exceed 400 square feet (37 m2) and shall be based on the sprinkler listing and the sprinkler manufacturer’s installation instructions.

Sprinkler discharge shall not be blocked by obstructions unless additional sprinklers are installed to protect the obstructed area. Additional sprinklers shall not be required where the sprinkler separation from obstructions complies with either the minimum distance indicated in Figure R313.3.2.4.2 or the minimum distances specified in the sprinkler manufacturer’s instructions where the manufacturer’s instructions permit a lesser distance.

For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm.

FIGURE R313.3.2.4.2

MINIMUM ALLOWABLE DISTANCE BETWEEN SPRINKLER AND OBSTRUCTION

Pendent sprinklers within 3 feet (915 mm) of the center of a ceiling fan, surface- mounted ceiling luminaire or similar object shall be considered to be obstructed, and additional sprinklers shall be installed.
Sidewall sprinklers within 5 feet (1524 mm) of the center of a ceiling fan, surface- mounted ceiling luminaire or similar object shall be considered to be obstructed, and additional sprinklers shall be installed.
The solvent cementing of threaded adapter fittings shall be completed and threaded adapters for sprinklers shall be verified as being clear of excess cement prior to the installation of sprinklers on systems assembled with solvent cement.
Painting, caulking or modifying of sprinklers shall be prohibited. Sprinklers that have been painted, caulked, modified or damaged shall be replaced with new sprinklers.

Sprinkler piping shall be supported in accordance with the requirements for cold water distribution piping. Sprinkler piping shall comply with all requirements for cold water distribution piping. For multipurpose piping systems, the sprinkler piping shall connect to and be a part of the cold water distribution piping system.

Exception: For plastic piping, it shall be permissible to follow the manufacturer’s installation instructions.

Nonmetallic pipe and tubing, such as CPVC, PEX, and PE-RT shall be listed for use in residential fire sprinkler systems.

Nonmetallic pipe and tubing systems shall be protected from exposure to the living space by a layer of not less than 3/8 inch (9.5 mm) thick gypsum wallboard, 1/2 inch thick plywood (13 mm), or other material having a 15 minute fire rating.

Exceptions:

  1. Pipe protection shall not be required in areas that do not require protection with sprinklers as specified in Section R313.3.1.2.
  2. Pipe protection shall not be required where exposed piping is permitted by the pipe listing.
With the exception of shutoff valves for the entire water distribution system, valves shall not be installed in any location where the valve would isolate piping serving one or more sprinklers.
Piping beyond the service valve located at the beginning of the water distribution system shall not serve more than one dwelling.
A means to drain the sprinkler system shall be provided on the system side of the water distribution shutoff valve.
The flow for sizing the sprinkler piping system shall be based on the flow rating of each sprinkler in accordance with Section R313.3.4.1 and the calculation in accordance with Section R313.3.4.2.

The minimum required flow for each sprinkler shall be determined using the sprinkler manufacturer’s published data for the specific sprinkler model based on all of the following:

  1. The area of coverage.
  2. The ceiling configuration.
  3. The temperature rating.
  4. Any additional conditions specified by the sprinkler manufacturer.

The design flow rate for the system shall be based on the following:

  1. The design flow rate for a room having only one sprinkler shall be the flow rate required for that sprinkler, as determined by Section R313.3.4.1.
  2. The design flow rate for a room having two or more sprinklers a shall be determined by identifying the sprinkler in that room with the highest required flow rate, based on Section R313.3.4.1, and multiplying that flow rate by 2.
  3. Where the sprinkler manufacturer specifies different criteria for ceiling configurations that are not smooth, flat and horizontal, the required flow rate for that room shall comply with the sprinkler manufacturer’s instructions.
  4. The design flow rate for the sprinkler system shall be the flow required by the room with the largest flow rate, based on Items 1, 2 and 3.
  5. For the purpose of this section, it shall be permissible to reduce the design flow rate for a room by subdividing the space into two or more rooms, where each room is evaluated separately with respect to the required design flow rate. Each room shall be bounded by walls and a ceiling. Openings in walls shall have a lintel not less than 8 inches (203 mm) in depth and each lintel shall form a solid barrier between the ceiling and the top of the opening.
The water supply shall provide not less than the required design flow rate for sprinklers in accordance with Section R313.3.4.2 at a pressure not less than that used to comply with Section R313.3.6. Where a water supply serves both domestic and fire sprinkler systems, 5 gpm (19 L/min) shall be added to the sprinkler system demand at the point where the systems are connected, to determine the size of common piping and the size of the total water supply requirements where no provision is made to prevent flow into the domestic water system upon operation of a sprinkler. For multipurpose piping systems, the 5 gpm (19 L/min) demand shall be added at the domestic connection nearest the design area. This demand may be split between two domestic connections at 2.5 gpm (10 L/min) each.