ADOPTS WITH AMENDMENTS:

International Residential Code 2015 (IRC 2015)

Part I — Administrative

Part II — Definitions

Part III — Building Planning and Construction

Part IV — Energy Conservation

Part V — Mechanical

Part VI — Fuel Gas

Part VII — Plumbing

Part VIII — Electrical

Part IX — Referenced Standards

Heads up: There are no amended sections in this chapter.

N1101.1 Scope

AMENDMENT
This section has been amended at the state or city level.
This chapter regulates the energy efficiency for the design and construction of buildings regulated by this code.
Exception:
  1. In accordance with N.C.G.S. 143-138 (b19), no energy conservation code provisions shall apply to detached and attached garages located on the same lot as a dwelling.
Note: The text of the following Sections N1101.2 through N1105 is extracted from the 2018 edition of the North Carolina Energy Conservation Code—Residential Provisions and has been editorially revised to conform to the scope and application of this code. The section numbers appearing in parenthesis after each section number are the section numbers of the corresponding text in the North Carolina Energy Conservation Code—Residential Provisions.
UpCodes note: The delayed effective date of the Exception is January 1, 2020.
This chapter shall regulate the design and construction of buildings for the effective use and conservation of energy over the useful life of each building. This chapter is intended to provide flexibility to permit the use of innovative approaches and techniques to achieve this objective. This chapter is not intended to abridge safety, health or environmental requirements contained in other applicable codes or ordinances.
The building official shall be permitted to approve specific computer software, worksheets, compliance manuals and other similar materials that meet the intent of this code.

N1101.4 (R102.1.1) Above Code Programs

AMENDMENT
This section has been amended at the state or city level.

N1101.5 (R103.2) Information on Construction Documents

AMENDMENT
This section has been amended at the state or city level.

N1101.5.1 (R103.2.1) Thermal Envelope Depiction

AMENDMENT
This section has been amended at the state or city level.

N1101.6 (R202) Defined Terms

AMENDMENT
This section has been amended at the state or city level.
See Chapter 2.

N1101.7 (R301.1) Climate Zones

AMENDMENT
This section has been amended at the state or city level.
Climate zones from Figure N1101.7 or Table N1101.7 shall be used in determining the applicable requirements in Sections N1101 through N1111.




Warm and humid counties are below the dashed line.
FIGURE N1101.7 (R301.1)
CLIMATE ZONES
TABLE N1101.7 (R301.1)
CLIMATE ZONES, MOISTURE REGIMES, AND WARM-HUMID DESIGNATIONS BY STATE, COUNTY AND TERRITORY
Key: A — Moist.
Asterisk (*) indicates a warm-humid location.
BY COUNTY
NORTH CAROLINA
4A Alamance
4A Alexander
5A Alleghany
3A Anson
5A Ashe
5A Avery
3A Beaufort
4A Bertie
3A Bladen
3A Brunswick*
4A Buncombe
4A Burke
3A Cabarrus
4A Caldwell
3A Camden
3A Carteret*
4A Caswell
4A Catawba
4A Chatham
4A Cherokee
3A Chowan
4A Clay
4A Cleveland
3A Columbus*
3A Craven
3A Cumberland
3A Currituck
3A Dare
3A Davidson
4A Davie
3A Duplin
4A Durham
3A Edgecombe
4A Forsyth
4A Franklin
3A Gaston
4A Gates
4A Graham
4A Granville
3A Greene
4A Guilford
4A Halifax
4A Harnett
4A Haywood
4A Henderson
4A Hertford
3A Hoke
3A Hyde
4A Iredell
4A Jackson
3A Johnston
3A Jones
4A Lee
3A Lenoir
4A Lincoln
4A Macon
4A Madison
3A Martin
4A McDowell
3A Mecklenburg
5A Mitchell
3A Montgomery
3A Moore
4A Nash
3A New Hanover*
4A Northampton
3A Onslow*
4A Orange
3A Pamlico
3A Pasquotank
3A Pender*
3A Perquimans
4A Person
3A Pitt
4A Polk
3A Randolph
3A Richmond
3A Robeson
4A Rockingham
3A Rowan
4A Rutherford
3A Sampson
3A Scotland
3A Stanly
4A Stokes
4A Surry
4A Swain
4A Transylvania
3A Tyrrell
3A Union
4A Vance
4A Wake
4A Warren
3A Washington
5A Watauga
3A Wayne
4A Wilkes
3A Wilson
4A Yadkin
5A Yancey
Warm humid counties are identified in Table N1101.7 by an asterisk.

N1101.7.2 (R301.3) International Climate Zones

AMENDMENT
This section has been amended at the state or city level.

N1101.8 (R301.4) Tropical Climate Zone

AMENDMENT
This section has been amended at the state or city level.
The interior design temperatures used for heating and cooling load calculations shall be a maximum of 72°F (22°C) for heating and minimum of 75°F (24°C) for cooling.
Materials, systems and equipment shall be identified in a manner that will allow a determination of compliance with the applicable provisions of this code.
An R-value identification mark shall be applied by the manufacturer to each piece of building thermal envelope insulation 12 inches (305 mm) or greater in width. Alternately, the insulation installers shall provide a certification listing the type, manufacturer and R-value of insulation installed in each element of the building thermal envelope. For blown or sprayed insulation (fiberglass and cellulose), the initial installed thickness, settled thickness, settled R-value, installed density, coverage area and number of bags installed shall be listed on the certification. For insulated siding, the R-value shall be labeled on the product's package and shall be listed on the certification. The insulation installer shall sign, date and post the certification in a conspicuous location on the job site.
The thickness of blown-in or sprayed roof/ceiling insulation (fiberglass or cellulose) shall be written in inches (mm) on markers that are installed at least one for every 300 square feet (28 m2) throughout the attic space. The markers shall be affixed to the trusses or joists and marked with the minimum initial installed thickness with numbers not less than 1 inch (25 mm) in height. Each marker shall face the attic access opening. Spray polyurethane foam thickness and installed R-value shall be listed on certification provided by the insulation installer.
Insulating materials shall be installed such that the manufacturer's R-value mark is readily observable upon inspection.

N1101.10.3 (R303.1.3) Fenestration Product Rating

AMENDMENT
This section has been amended at the state or city level.
U-factors of fenestration products (windows, doors and skylights) shall be determined in accordance with NFRC 100. U-factors shall be determined by an accredited, independent laboratory, and labeled and certified by the manufacturer. Products lacking such a labeled U-factor shall be assigned a default U-factor from Tables N1101.10.3(1) or N1101.10.3(2). The solar heat gain coefficient (SHGC) and visible transmittance (VT) of glazed fenestration products (windows, glazed doors and skylights) shall be determined in accordance with NFRC 200 by an accredited, independent laboratory, and labeled and certified by the manufacturer. Products lacking such a labeled SHGC or VT shall be assigned a default SHGC or VT from Table N1101.10.3(3).

Exception: When a garage door is a part of the building thermal envelope, garage door U-factors shall be determined in accordance with either NFRC 100 or ANSI/DASMA 105.

TABLE N1101.10.3(1) [R303.1.3(1)]
DEFAULT GLAZED FENESTRATION U-FACTORS
FRAME TYPE SINGLE
PANE
DOUBLE
PANE
SKYLIGHT
Single Double
Metal 1.20 0.80 2.00 1.30
Metal with Thermal Break 1.10 0.65 1.90 1.10
Nonmetal or Metal Clad 0.95 0.55 1.75 1.05
Glazed Block 0.60


TABLE N1101.10.3(2) [R303.1.3(2)]
DEFAULT DOOR U-FACTORS
DOOR TYPE U-FACTOR
Uninsulated Metal 1.20
Insulated Metal 0.60
Wood 0.50
Insulated, nonmetal edge, max 45% glazing,
any glazing double pane
0.35


TABLE N1101.10.3(3) [R303.1.3(3)]
DEFAULT GLAZED FENESTRATION SHGC AND VT
SINGLE GLAZED DOUBLE GLAZED GLAZED
BLOCK
Clear Tinted Clear Tinted
SHGC 0.8 0.7 0.7 0.6 0.6
VT 0.6 0.3 0.6 0.3 0.6
The thermal resistance (R-value) of insulation shall be determined in accordance with the U.S. Federal Trade Commission R-value rule (CFR Title 16, Part 460) in units of h × ft2 × °F/Btu at a mean temperature of 75°F (24°C).
The thermal resistance (R-value) of insulated siding shall be determined in accordance with ASTM C 1363. Installation for testing shall be in accordance with the manufacturer's installation instructions.
All materials, systems and equipment shall be installed in accordance with the manufacturer's instructions and this code.

N1101.11.1 (R303.2.1) Protection of Exposed Foundation Insulation

AMENDMENT
This section has been amended at the state or city level.
Insulation applied to the exterior of basement walls, crawlspace walls and the perimeter of slab-on-grade floors shall have an opaque and weather-resistant protective covering to prevent the degradation of the insulation's thermal performance. The protective covering shall cover the exposed exterior insulation and extend not less than 6 inches (153 mm) below grade.

N1101.12 (R303.3) Maintenance Information

AMENDMENT
This section has been amended at the state or city level.
Maintenance instructions shall be furnished for equipment and systems that require preventive maintenance.

N1101.13 (R401.2) Compliance

AMENDMENT
This section has been amended at the state or city level.
Projects shall comply with one of the following:
  1. Sections N1101.14 through N1104.
  2. Section N1105 and the provisions of Sections N1101.14 through N1104 labeled "Mandatory."
  3. An energy rating index (ERI) approach in Section N1106.
  4. North Carolina specific REScheck™ shall be permitted to demonstrate compliance with this code. Envelope requirements may not be traded off against the use of high efficiency heating or cooling equipment. No trade-off calculations are needed for required termite inspection and treatment gaps.
UpCodes note: The 2017-2021 Approved Amendments 201309-Residential Code has an update to this section:

Projects shall comply with one of the following:
  1. Section N1101.14 through N1104.
  2. Section N1105 and the provisions of Section N1101.14 labeled "Mandatory."
  3. An energy rating index (ERI) approach in Section N1106.
  4. REScheck keyed to the 2018 IECC shall be permitted to demonstrate compliance with this Code. Envelope requirements may not be traded off against the use of high efficiency heating or cooling equipment. No tradeoff calculations are needed for required termite inspection and treatment gaps.
The delayed effective date of this Rule is January 1, 2022.The Statutory authority for Rule-making is G. S. 143-136; 143-138.

N1101.13.1 (R401.2.1) Tropical Zone

AMENDMENT
This section has been amended at the state or city level.

N1101.14 (R401.3) Certificate (Mandatory)

AMENDMENT
This section has been amended at the state or city level.
A permanent certificate shall be posted on or in the electrical distribution panel, in the attic next to the attic insulation card, or inside a kitchen cabinet or other approved location. The certificate shall not cover or obstruct the visibility of the circuit directory label, service disconnect label or other required labels. The builder, permit holder, or registered design professional shall be responsible for completing the certificate. The certificate shall list the predominant R-values of insulation installed in or on ceiling/roof, walls, foundation (slab, basement wall, crawlspace wall and floor) and ducts outside conditioned spaces; and the U-factors for fenestration and the solar heat gain coefficient (SHGC) of fenestration. Where there is more than one value for each component, the certificate shall list the value covering the largest area. The certificate shall indicate whether the building air leakage was visually inspected as required in Section N1102.4.2.1 or provide results of the air leakage testing required in Section N1102.4.2.2. The certificate shall provide results of the duct leakage test required in Section N1103.3.3. Appendix E-1 contains a sample certificate.

N1101.15 (R401.4) Additional Voluntary Criteria for Increasing Residential Energy Efficiency

AMENDMENT
This section has been amended at the state or city level.
Appendix E-4 contains additional voluntary measures for increasing residential energy efficiency beyond code minimums. Implementation of the increased energy efficiency measures is strictly voluntary at the option of the permit holder. The sole purpose of the appendix is to provide guidance for achieving additional residential energy efficiency improvements that have been evaluated to be those that are most cost effective for achieving an additional 10-15 percent improvement in energy efficiency beyond code minimums.
The building thermal envelope shall meet the requirements of Sections N1102.1.1 through N1102.1.5.

Exception: The following low energy buildings, or portions thereof, separated from the remainder of the building by building thermal envelope assemblies complying with this section shall be exempt from the building thermal envelope provisions of Section N1102.
  1. Those with a peak design rate of energy usage less than 3.4 Btu/h • ft2 (10.7 W/m2) or 1.0 watt/ft2 of floor area for space conditioning purposes.
  2. Those that do not contain conditioned space.

N1102.1.1 (R402.1.1) Vapor Retarder

AMENDMENT
This section has been amended at the state or city level.

N1102.1.2 (R402.1.2) Insulation and Fenestration Criteria

AMENDMENT
This section has been amended at the state or city level.
The building thermal envelope shall meet the requirements of Table N1102.1.2 based on the climate zone specified in Section N1101.7.

TABLE N1102.1.2 (R402.1.2)
INSULATION AND FENESTRATION REQUIREMENTS BY COMPONENTa
CLIMATE
ZONE
FENESTRATION
U-FACTORb, j
SKYLIGHTb
U-FACTOR
GLAZED
FENESTRATION
SHGCb, k
CEILING
R-VALUEm
WOOD
FRAME WALL
R-VALUE
MASS
WALL
R-VALUEi
FLOOR
R-VALUE
BASEMENTc, o
WALL
R-VALUE
SLABd
R-VALUE
& DEPTH
CRAWL
SPACEc

WALL
R-VALUE
3 0.35 0.55  0.30 38 or 30ci  15 or 13 + 2.5h  5/13 or 5/10ci 19 5/13f 0 5/13
4
0.35 0.55  0.30  38 or 30ci  15 or 13 + 2.5h  5/13 or 5/10ci 19  10/15 10  10/15
5
 0.35 0.55 NR  38 or 30ci  19n or 13 + 5
or 15 + 3h
13/17 or 13/12.5 ci 30g  10/15 10  10/19

For SI: 1 foot = 304.8 mm.
  1. R-values are minimums. U-factors and SHGC are maximums. When insulation is installed in a cavity which is less than the label or design thickness of the insulation, the installed R-value of the insulation shall not be less than the R-value specified in the table.
  2. The fenestration U-factor column excludes skylights. The SHGC column applies to all glazed fenestration.

  3.   "10/15" means R-10 continuous insulation on the interior or exterior of the home or  R-15 cavity insulation at the interior of the basement wall or crawl space wall.
  4. R-5 shall be added to the required slab edge R-values for heated slabs.  For monolithic slabs, insulation shall be applied from the inspection gap downward to the bottom of the footing or a maximum of 24 inches below grade, whichever is less. For floating slabs, insulation shall extend to the bottom of the foundation wall or 24 inches, whichever is less. (See Appendix O).
  5. Deleted.
  6. Basement wall insulation is not required in warm-humid locations as defined by Figure  N1101.7 and Table N1101.7.
  7. Or insulation sufficient to fill the framing cavity, R-19 minimum.
  8. The first value is cavity insulation, the second value is continuous insulation, so "13+5" means R-13 cavity insulation plus R-5 continuous insulation If structural sheathing covers 25 percent or less of the exterior, insulating sheathing is not required where structural sheathing is used. If structural sheathing covers more than 25 percent of exterior, structural sheathing shall be supplemented with insulated sheathing of at least R-2.
  9. The second R-value applies when more than half the insulation is on the interior of the mass wall.
  10. In addition to the exemption in Section N1102.3.3, a maximum of two glazed fenestration product assemblies having a U-factor no greater than 0.55 shall be permitted to be substituted for minimum code compliant fenestration product assemblies without penalty.
  11. In addition to the exemption in Section N112.3.3, a maximum of two glazed fenestration product assemblies having a SHGC no greater than 0.70 shall be permitted to be substituted for minimum code compliant fenestration product assemblies without penalty.
  12. R-30 shall be deemed to satisfy the ceiling insulation requirement wherever the full height of uncompressed R-30 insulation extends over the wall top plate at the eaves. Otherwise R-38 insulation is required where adequate clearance exists or insulation must extend to either the insulation baffle or within 1 inch of the attic roof deck.
  13. Table value required except for roof edge where the space is limited by the pitch of the roof; there the insulation must fill the space up to the air baffle.
  14. R -19 fiberglass batts compressed and installed in a nominal 2 × 6 framing cavity is deemed to comply. Fiberglass batts rated R-19 or higher compressed and installed in a 2 × 4 wall is not deemed to comply.
  15. Basement wall meeting the minimum mass wall specific heat content requirement may use the mass wall R-value as the minimum requirement.
Insulation material used in layers, such as framing cavity insulation, or continuous insulation shall be summed to compute the corresponding component R-value. The manufacturer's settled R-value shall be used for blown insulation. Computed R-values shall not include an R-value for other building materials or air films. Where insulated siding is used for the purpose of complying with the continuous insulation requirements of Table N1102.1.2, the manufacturer's labeled R-value for insulated siding shall be reduced by R-0.6.

N1102.1.4 (R402.1.4) U-factor Alternative

AMENDMENT
This section has been amended at the state or city level.
An assembly with a U-factor equal to or less than that specified in Table N1102.1.4 shall be permitted as an alternative to the R-value in Table N1102.1.2.

TABLE N1102.1.4 (R402.1.4)
EQUIVALENT U-FACTORSa
CLIMATE
ZONE
FENESTRATION
U-FACTORd
SKYLIGHT
U-FACTOR
CEILING
U-FACTOR
FRAME
WALL
U-FACTOR
MASS WALL
U-FACTORb
FLOOR
U-FACTOR
BASEMENT
WALL
U-FACTOR
CRAWL
SPACE WALL
U-FACTOR
3 0.35 0.55 0.030  0.077  0.141 0.047  0.091c 0.136
4 0.35 0.55  0.030  0.077  0.141 0.047 0.059 0.065
5  0.35 0.55  0.030 0.061 0.082 0.033  0.059  0.065

  1. Nonfenestration U-factors shall be obtained from measurement, calculation or an approved source.
  2. When more than half the insulation is on the interior, the mass wall U-factors shall be a maximum of  0.07 in Climate  Zone 3,  0.07 in Climate  Zone 4  and 0.054 in Climate Zone 5.
  3. Basement wall U-factor of 0.360 in warm-humid locations as defined by Figure N1101.7 (R301.1) and Table 1101.7 (R301.1).
  4. A maximum of two glazed fenestration product assemblies having a U-factor no greater than 0.55 and a SHGC no greater than 0.70 shall be permitted to be substituted for minimum code compliant fenestration product assemblies without penalty. When applying this note and using the REScheck "UA Trade-off" compliance method to allow continued use of the software, the applicable fenestration products shall be modeled as meeting the U-factor of 0.35 and the SHGC of 0.30, as applicable, but the fenestration products actual U-factor and actual SHGC shall be noted in the comments section of the software for documentation of application of this note to the applicable products. Compliance for these substitute products shall be verified compared to the allowed substituted maximum U-value requirement and maximum SHGC requirement, as applicable.
If the total building thermal envelope UA (sum of U-factor times assembly area) is less than or equal to the total UA resulting from using the U-factors in Table N1102.1.4 (multiplied by the same assembly area as in the proposed building), the building shall be considered in compliance with Table N1102.1.2. The UA calculation shall be done using a method consistent with the ASHRAE Handbook of Fundamentals and shall include the thermal bridging effects of framing materials. The SHGC requirements shall be met in addition to UA compliance.

N1102.2 (R402.2) Specific Insulation Requirements (Prescriptive)

AMENDMENT
This section has been amended at the state or city level.
In addition to the requirements of Section N1102.1, insulation shall meet the specific requirements of Sections N1102.2.1 through N1102.2.15.

N1102.2.1 (R402.2.1) Ceilings With Attic Spaces

AMENDMENT
This section has been amended at the state or city level.
Where Section R1102.1.2 would require R-38 insulation in the ceiling, installing R-30 over 100 percent of the ceiling area requiring insulation shall be deemed to satisfy the requirement for R-38 wherever the full height of uncompressed R-30 insulation extends over the wall top plate at the eaves. This reduction shall not apply to the U-factor alternative approach in Section R1102.1.4 and the total UA alternative in Section R1102.1.5.

Exceptions:
  1. When insulation is installed in a fully enclosed attic floor system, as described in Appendix E-2.1, R-30 shall be deemed compliant.
  2. In roof edge and other details such as bay windows, dormers, and similar areas where the space is limited, the insulation must fill the space up to the air baffle.

N1102.2.2 (R402.2.2) Ceilings Without Attic Spaces

AMENDMENT
This section has been amended at the state or city level.
Where Section N1102.1.2 would require R-38 insulation and the design of the roof/ceiling assembly, including cathedral ceilings, bay windows and other similar areas, does not allow sufficient space for the required insulation, the minimum required insulation for such roof/ceiling assemblies shall be R-30. This reduction of insulation from the requirements of Section N1102.1.2 shall be limited to 500 square feet (46 m2) of the total insulated ceiling area. This reduction shall not apply to the U-factor alternative approach in Section N1102.1.4 and the total UA alternative in Section N1102.1.5.

N1102.2.3 (R402.2.3) Eave Soffit Baffle

AMENDMENT
This section has been amended at the state or city level.
For air-permeable insulations in vented attics, a baffle shall be installed adjacent to soffit vents. The baffle shall extend over the top of the attic insulation. The baffle shall be permitted to be any solid material.

N1102.2.4 (R402.2.4) Access Hatches and Doors

AMENDMENT
This section has been amended at the state or city level.
Horizontal access hatches from conditioned spaces to unconditioned spaces such as attics and crawl spaces shall be weatherstripped and insulated to an R-10 minimum value and vertical doors to such spaces shall be weatherstripped and insulated to R-5. Access shall be provided to all equipment that prevents damaging or compressing the insulation. A wood-framed or equivalent baffle or retainer is required to be provided when loose-fill insulation is installed, the purpose of which is to prevent the loose-fill insulation from spilling into the living space when the attic access is opened, and to provide a permanent means of maintaining the installed R-value of the loose-fill insulation.

Exceptions:
  1. Full size vertical doors that provide access from conditioned to unconditioned spaces shall be permitted to meet the fenestration requirements of Table N1102.1.2 based on the applicable climate zone specified in Section N1101.7.
  2. Pull down stair systems shall be weatherstripped and insulated with a minimum R-5 insulation. The insulation shall not interfere with proper operation of the stair. Nonrigid insulation materials are not allowed. Additional insulation systems that enclose the stair system from above are allowed. Exposed foam plastic must meet the provisions of Section R318.

N1102.2.5 (R402.2.5) Mass Walls

AMENDMENT
This section has been amended at the state or city level.
Mass walls for the purposes of this chapter shall be considered walls of concrete block, concrete, insulated concrete form (ICF), masonry cavity, brick (other than brick veneer), earth (adobe, compressed earth block, rammed earth) and solid timber/logs, or any other walls meeting the following. Masonry or concrete walls having a mass greater than or equal to 30 pounds per square foot (146 kg/m2). Solid wood walls having a mass greater than 20 pounds per square foot (98 kg/m2). Any walls having a heat capacity greater than or equal to 6 Btu/ft2 • °F[266 J/(m2 • K)].
Steel-frame ceilings, walls, and floors shall meet the insulation requirements of Table N1102.2.6 or shall meet the U-factor requirements of Table N1102.1.4. The calculation of the U-factor for a steel-frame envelope assembly shall use a series-parallel path calculation method.

TABLE N1102.2.6 (R402.2.6)
STEEL-FRAME CEILING, WALL AND FLOOR INSULATION (R-VALUE)
WOOD FRAME
R-VALUE
REQUIREMENT
COLD-FORMED STEEL
EQUIVALENT R-VALUEa
Steel Truss Ceilingsb
R-30 R-38 or R-30 + 3 or R-26 + 5
R-38 R-49 or R-38 + 3
R-49 R-38 + 5
Steel Joist Ceilingsb
R-30 R-38 in 2 × 4 or 2 × 6 or 2 × 8 R-49
in any framing
R-38 R-49 in 2 × 4 or 2 × 6 or 2 × 8 or 2 × 10
Steel-Framed Wall, 16" on center
R-13 R-13 + 4.2 or R-19 + 2.1 or R-21 + 2.8 or
R-0 + 9.3 or R-15 + 3.8 or R-21 + 3.1
R-13 + 3 R-0 + 11.2 or R-13 + 6.1 or R-15 + 5.7 or
R-19 + 5.0 or R-21 + 4.7
R-20 R-0 + 14.0 or R-13 + 8.9 or R-15 + 8.5 or
R-19 + 7.8 or R-19 + 6.2 or R-21 + 7.5
R-20 + 5 R-13 + 12.7 or R-15 + 12.3 or R-19 + 11.6 or
R-21 + 11.3 or R-25 + 10.9
R-21 R-0 + 14.6 or R-13 + 9.5 or R-15 + 9.1 or
R-19 + 8.4 or R-21 + 8.1 or R-25 + 7.7
Steel-Framed Wall, 24" on center
R-13 R-0 + 9.3 or R-13 + 3.0 or R-15 + 2.4
R-13 + 3 R-0 + 11.2 or R-13 + 4.9 or R-15 + 4.3 or
R-19 + 3.5 or R-21 + 3.1
R-20 R-0 + 14.0 or R-13 + 7.7 or R-15 + 7.1 or
R-19 + 6.3 or R-21 + 5.9
R-20 + 5 R-13 + 11.5 or R-15 + 10.9 or R-19 + 10.1 or
R-21 + 9.7 or R-25 + 9.1
R-21 R-0 + 14.6 or R-13 + 8.3 or R-15 + 7.7 or
R-19 + 6.9 or R-21 + 6.5 or R-25 + 5.9
Steel Joist Floor
R-13 R-19 in 2 × 6, or R-19 + 6 in 2 × 8 or 2 × 10
R-19 R-19 + 6 in 2 × 6, or R-19 + 12 in 2 × 8 or 2 × 10
  1. Cavity insulation R-value is listed first, followed by continuous insulation R-value.
  2. Insulation exceeding the height of the framing shall cover the framing.

N1102.2.7 (R402.2.7) Walls With Partial Structural Sheathing

AMENDMENT
This section has been amended at the state or city level.
If structural sheathing covers 25 percent or less of the exterior, insulating sheathing is not required where structural sheathing is used. If structural sheathing covers more than 25 percent of the exterior, structural sheathing shall be supplemented with insulated sheathing of at least R-2. This reduction shall not apply to the U-factor alternative approach in Section N1102.1.4 and the total UA alternative in Section N1102.1.5.

N1102.2.8 (R402.2.8) Floors

AMENDMENT
This section has been amended at the state or city level.
Floor framing-cavity insulation shall be installed to maintain permanent contact with the underside of the subfloor decking. The distance between tension support wires or other devices that hold the floor insulation in place against the subfloor shall be no more than 18 inches (457 mm). In addition, supports shall be located no further than 6 inches (152 mm) from each end of the insulation.

Exception: An enclosed floor cavity such as garage ceilings, cantilevers or buildings on pilings with an enclosed floor cavity with the insulation fully in contact with the lower air barrier. In this case, the band boards shall be insulated to maintain thermal envelope continuity.

N1102.2.9 (R402.2.9) Basement Walls

AMENDMENT
This section has been amended at the state or city level.
Walls associated with conditioned basements shall be insulated from the top of the basement wall down to 10 feet (3048 mm) below grade or to the basement floor, whichever is less. Walls associated with unconditioned basements shall meet this requirement unless the floor overhead is insulated in accordance with Sections N1102.1.2 and N1102.2.8. Foam plastic insulation applied to exterior of basement walls shall be provided with termite inspection and treatment gaps in accordance with Appendix O.

N1102.2.10 (R402.2.10) Slab-On-Grade Floors

AMENDMENT
This section has been amended at the state or city level.
Slab-on-grade floors with a floor surface less than 12 inches (305 mm) below grade shall be insulated in accordance with Table N1102.1.2. The top edge of the insulation installed between the exterior wall and the edge of the interior slab shall be permitted to be cut at a 45-degree (0.79 rad) angle away from the exterior wall. Slab edge insulation shall have a 2-inch (51 mm) termite inspection gap consistent with Appendix O of this code.

N1102.2.11 (R402.2.11) Closed Crawl Space Walls

AMENDMENT
This section has been amended at the state or city level.
Where the floor above a closed crawl space is not insulated, the exterior crawlspace walls shall be insulated in accordance with Table N1102.1.2.

     Wall insulation may be located in any combination of the outside and inside wall surfaces and within the structural cavities or materials of the wall system.

     Wall insulation requires that the exterior wall band joist area of the floor frame be insulated. Wall insulation shall begin 3 inches (76 mm) below the top of the masonry foundation wall and shall extend down to 3 inches (76 mm) above the top of the footing or concrete floor, 3 inches (76 mm) above the interior ground surface or 24 inches (610 mm) below the outside finished ground level, whichever is less. (See Appendix E-2.2 details.)

     Termite inspection, clearance, and wicking gaps are allowed in wall insulation systems. Insulation may be omitted in the gap area without energy penalty. The allowable insulation gap widths are listed in Table N1102.2.11. If gap width exceeds the allowances, one of the following energy compliance options shall be met:
  1. Wall insulation is not allowed and the required insulation value shall be provided in the floor system.
  2. Compliance shall be demonstrated with energy trade-off methods provided by a North Carolina specific version of RESCHECK or the UA Alternative method or Section N1105.
TABLE N1102.2.11
WALL INSULATION ALLOWANCES FOR TERMITE TREATMENT AND INSULATION GAPS
GAP WIDTH
(inches)
INSULATION LOCATION GAP DESCRIPTION
Minimum Maximum
2 3 Outside Above grade inspection between top of insulation
and bottom of siding
4 6 Outside Below grade treatment
3a 4a Inside Wall inspection between top of insulation and bottom of sill
3a 4a Inside Clearance/wicking space between bottom of insulation
and top of ground surface, footing, or concrete floor
For SI: 1 inch = 25.4 mm.
  1. No insulation shall be required on masonry walls of 9 inches in height or less.
Insulation shall not be required on the horizontal portion of the foundation that supports a masonry veneer.

N1102.2.13 (R402.2.13) Sunroom Insulation

AMENDMENT
This section has been amended at the state or city level.
Sunrooms enclosing conditioned spaces shall meet the insulation requirements of this code.

Exception: For sunrooms with thermal isolation, and enclosing conditioned spaces, the following exceptions to the insulation requirements of this code shall apply:
  1. The minimum ceiling insulation R-values shall be R-19 in Zones 3 and 4 and R-24 in Zone 5.
  2. The minimum wall R-value shall be R-13 in all climate zones. New walls separating a sunroom with a thermal isolation from conditioned space shall meet the building thermal envelope requirements of this code.

N1102.2.14 (R402.2.14) Framed Cavity Walls

AMENDMENT
This section has been amended at the state or city level.
The exterior thermal envelope wall insulation shall be installed in contact and continuous alignment with the building envelope air barrier. Insulation shall be free from installation gaps, voids, or compression. For framed walls, the cavity insulation shall be enclosed on all sides with solid rigid material or an air barrier material. Polyethylene shall not be allowed. Rim joists are not required to be enclosed on all sides. Wall insulation shall be enclosed at the following locations when installed on exterior walls prior to being covered by subsequent construction, consistent with Appendix E-2.3 of this code:
  1. Tubs
  2. Showers
  3. Stairs
  4. Fireplace units (Enclose with rigid material only)

N1102.2.15 (R402.2.15) Attic Knee Walls

AMENDMENT
This section has been amended at the state or city level.
Enclosure of wall cavity insulation also applies to walls that adjoin attic spaces by placing a rigid material or air barrier material on the attic space side of the wall on the attic space side of the wall consistent with Appendix E-2.3 of this code. Noninsulating class I vapor retarders, such as polyethylene, shall not be allowed.
In addition to the requirements of Section N1102, fenestration shall comply with Sections N1102.3.1 through N1102.3.5.
An area-weighted average of fenestration products shall be permitted to satisfy the U-factor requirements.
An area-weighted average of fenestration products more than 50-percent glazed shall be permitted to satisfy the SHGC requirements.

Dynamic glazing shall be permitted to satisfy the SHGC requirements of Table N1102.1.2 provided the ratio of the higher to lower labeled SHGC is greater than or equal to 2.4, and the dynamic glazing is automatically controlled to modulate the amount of solar gain into the space in multiple steps. Dynamic glazing shall be considered separately from other fenestration, and area-weighted averaging with other fenestration that is not dynamic glazing shall not be permitted.

Exception: Dynamic glazing is not required to comply with this section when both the lower and higher labeled SHGC already comply with the requirements of Table N1102.1.2.

N1102.3.3 (R402.3.3) Glazed Fenestration Exemption

AMENDMENT
This section has been amended at the state or city level.
Either two glazed fenestration assemblies or up to 24 square feet (2.2 m2) of glazed fenestration per dwelling unit shall be permitted to be exempt from U-factor and SHGC requirements in Section N1102.1.2. This exemption shall not apply to the U-factor alternative approach in Section N1102.1.4 and the total UA alternative in Section N1102.1.5.

N1102.3.4 (R402.3.4) Opaque Door Exemption

AMENDMENT
This section has been amended at the state or city level.
Opaque doors separating conditioned from unconditioned space shall have a maximum U-factor of 0.35.

Exception: One side-hinged opaque door assembly is exempted from the U-factor requirement in Section N1102.1.2. This exemption shall not apply to the U-factor alternative approach in Section N1102.1.4 and the total UA alternative in Section N1102.1.5.

N1102.3.5 (R402.3.5) Sunroom Fenestration

AMENDMENT
This section has been amended at the state or city level.
Sunrooms enclosing conditioned space shall meet the fenestration requirements of this code.

Exceptions:
  1. For sunrooms with thermal isolation and enclosing conditioned space in Climate Zones 3 through 5, the maximum fenestration U-factor shall be 0.45 and the maximum skylight U-factor shall be 0.75. Sunrooms with cooling systems shall have a maximum fenestration SHGC of 0.40 for all glazing.
  2. A maximum of two glazed fenestration product assemblies having a U-factor no greater than 0.55 and, when cooling is provided, a SHGC no greater than 0.70 shall be permitted to be substituted for minimum code compliant fenestration product assemblies without penalty.
     New fenestration separating the sunroom with thermal isolation from conditioned space shall meet the building thermal envelope requirements of this code.

N1102.4 (R402.4) Air Leakage Control (Mandatory)

AMENDMENT
This section has been amended at the state or city level.
The building thermal envelope shall be constructed to limit air leakage in accordance with the requirements of Sections N1102.4.1 through N1102.4.6.

N1102.4.1 (R402.4.1) Building Thermal Envelope

AMENDMENT
This section has been amended at the state or city level.
The building thermal envelope shall be durably sealed to limit infiltration. The sealing methods between dissimilar materials shall allow for differential expansion and contraction. For all homes, where present, the following shall be caulked, gasketed, weatherstripped or otherwise sealed with an air barrier material, or solid material consistent with Appendix E-2.4 of this code:
  1. Blocking and sealing floor/ceiling systems and under knee walls open to unconditioned or exterior space.
  2. Capping and sealing shafts or chases, including flue shafts.
  3. Capping and sealing soffit or dropped ceiling areas.
  4. Sealing HVAC register boots and return boxes to subfloor or drywall.
  5. Seal exterior house wrap material joints and seams in accordance with manufacturer's instructions or, if house wrap joints are not sealed, seal exterior sheathing and exposed band joist joints including perimeter joints and edges of these materials.

    Exceptions:
    1. Spray foam in building thermal envelope wall systems.
    2. Wall sheathing joints where wall sheathing is fully glued to framing.

N1102.4.1.1 (R402.4.1.1) Installation

AMENDMENT
This section has been amended at the state or city level.

N1102.4.1.2 (R402.4.1.2) Testing

AMENDMENT
This section has been amended at the state or city level.

N1102.4.2 Air Sealing

AMENDMENT
This section has been amended at the state or city level.
Building envelope air tightness shall be demonstrated by compliance with Section N1102.4.2.1 or N1102.4.2.2. Appendix E-3 contains optional sample worksheets for visual inspection or testing for the permit holder's use only.

TABLE N1102.4.2
AIR BARRIER INSPECTION
COMPONENT CRITERIA
Ceiling/attic Sealants or gaskets provide a continuous air barrier system joining the top plate of framed walls with either the ceiling drywall or the top edge of wall drywall to prevent air leakage. Top plate penetrations are sealed. For ceiling finishes that are not air barrier systems such as tongue-and-groove planks, air barrier systems (for example, taped house wrap), shall be used above the finish
Note: It is acceptable that sealants or gaskets applied as part of the application of the drywall will not be observable by the code official.
Walls Sill plate is gasketed or sealed to subfloor or slab.
Windows and doors Space between window and exterior door jambs and framing is
sealed.
Floors (including above-garage and cantilevered floors) Air barrier system is installed at any exposed edge of insulation.
Penetrations Utility penetrations through the building thermal envelope, including those for plumbing, electrical wiring, ductwork, security and fire alarm wiring, and control wiring, shall be sealed.
Garage separation Air sealing is provided between the garage and conditioned spaces. An air barrier system shall be installed between the ceiling system above the garage and the ceiling system of interior spaces.
Ceiling penetrations Ceiling electrical box penetrations and ceiling mechanical box penetrations shall be caulked, gasketed, or sealed at the penetration of the ceiling finish. See Appendix E-2.4.

Exception: Ceiling electrical boxes and ceiling mechanical boxes not penetrating the building thermal envelope.
Recessed lighting Recessed light fixtures are air tight, IC-rated, and sealed to drywall.

Exception: Fixtures in conditioned space.

N1102.4.2.1 Visual Inspection Option

AMENDMENT
This section has been amended at the state or city level.
Building envelope tightness shall be considered acceptable when items providing insulation enclosure in Section N1102.2.14 and enclosure and air sealing in Section N1102.2.15 and air sealing in Section N1102.4.1 are addressed and when the items listed in Table N1102.4.2, applicable to the method of construction, are certified by the builder, permit holder or registered design professional via the certificate in Appendix E-1.

N1102.4.2.2 Testing Option

AMENDMENT
This section has been amended at the state or city level.
Building envelope tightness shall be considered acceptable when items providing insulation enclosure in Section N1102.2.14 and enclosure and air sealing in Section N1102.2.15 and air sealing in Section N1102.4.1 are addressed and when tested air leakage is less than or equal to one of the two following performance measurements:

Test Criteria:
  1. 0.30 CFM50/Square Foot of Surface Area (SFSA) or
  2. Five (5) air changes per hour (ACH50)
     When tested with a blower door fan assembly, at a pressure of 33.5 psf (50 Pa). A single point depressurization, not temperature corrected, test is sufficient to comply with this provision, provided that the blower door fan assembly has been certified by the manufacturer to be capable of conducting tests in accordance with ASTM E779 or ASTM E1827. Testing shall occur after rough in and after installation of penetrations of the building envelope, including penetrations for utilities, plumbing, electrical, ventilation and combustion appliances. Testing shall be reported by the permit holder, a North Carolina licensed general contractor, a North Carolina licensed HVAC contractor, a North Carolina licensed Home Inspector, a registered design professional, a certified BPI envelope professional or a certified HERS rater.

During testing:
  1. Exterior windows and doors, fireplace and stove doors shall be closed, but not sealed;
  2. Dampers shall be closed, but not sealed, including exhaust, backdraft, and flue dampers;
  3. Interior doors shall be open;
  4. Exterior openings for continuous ventilation systems, air intake ducted to the return side of the conditioning system, and energy or heat recovery ventilators shall be closed and sealed;
  5. Heating and cooling system(s) shall be turned off; and
  6. Supply and return registers shall not be sealed.
     The air leakage information, building air leakage result, tester name, date, and contact information, shall be included on the certificate described in Section N1101.14.

     For Test Criteria 1 in this section, the report shall be produced in the following manner: perform the blower door test and record the CFM50. Calculate the total square feet of surface area for the building thermal envelope (all floors, ceilings, and walls including windows and doors, bounding conditioned space) and record the area. Divide CFM50 by the total square feet and record the result. If the result is less than or equal to [0.30 CFM50/SFSA] the envelope tightness is acceptable; or

     For Test Criteria 2, the report shall be produced in the following manner: Perform a blower door test and record the CFM50. Multiply the CFM50 by 60 minutes to create CFHour50 and record. Then calculate the total conditioned volume of the home and record. Divide the CFH50 by the total volume and record the result. If the result is less than or equal to 5 ACH50 the envelope tightness is acceptable.

N1102.4.2 N1102.4.3 (R402.4.2) (R402.4.3) Fireplaces

AMENDMENT
This section has been amended at the state or city level.
Site-built masonry fireplaces shall have flue dampers and comply with Section R1006 for combustion air.

N1102.4.3 N1102.4.4 (R402.4.3) (R402.4.4) Fenestration Air Leakage

AMENDMENT
This section has been amended at the state or city level.
Windows, skylights and sliding glass doors shall have an air infiltration rate of no more than 0.3 cfm per square foot (1.5 L/s/m2), and swinging doors no more than 0.5 cfm per square foot (2.6 L/s/m2), when tested according to NFRC 400 or AAMA/WDMA/CSA 101/I.S.2/A440 by an accredited, independent laboratory and listed and labeled by the manufacturer.

Exception: Field-fabricated windows, skylights and doors.

N1102.4.4 (R402.4.4) Rooms Containing Fuel-Burning Appliances

AMENDMENT
This section has been amended at the state or city level.

N1102.4.5 N1102.4.6 (R402.4.5)(R402.4.6) Recessed Lighting

AMENDMENT
This section has been amended at the state or city level.
Recessed luminaires installed in the building thermal envelope shall be sealed to limit air leakage between conditioned and unconditioned spaces. All recessed luminaires shall be IC-rated and labeled as having an air leakage rate not more than 2.0 cfm (0.944 L/s) when tested in accordance with ASTM E 283 at a 1.57 psf (75 Pa) pressure differential. All recessed luminaires shall be sealed with a gasket or caulk between the housing and the interior wall or ceiling covering.

N1102.5 (R402.5) Maximum Fenestration U-factor and SHGC (Mandatory)

AMENDMENT
This section has been amended at the state or city level.
The area-weighted average maximum fenestration U-factor permitted using trade-offs from Section N1102.1.5 shall be 0.48. Maximum skylight U-factors shall be 0.65 in Zones 4 and 5 and 0.60 in Zone 3. The areaweighted average maximum fenestration SHGC permitted using trade-offs from Section N1105 in Zone 3 shall be 0.50.

Exception: A maximum of two glazed fenestration product assemblies having a U-factor no greater than 0.55 and a SHGC no greater than 0.70 shall be permitted to be substituted for minimum code compliant fenestration product assemblies without penalty.
At least one thermostat shall be provided for each separate heating and cooling system.

N1103.1.1 (R403.1.1) Programmable Thermostat

AMENDMENT
This section has been amended at the state or city level.
When the primary heating system is a forced air furnace or heat pump, the thermostat controlling the primary heating or cooling system of the dwelling unit shall be capable of controlling the heating and cooling system on a daily schedule to maintain different temperature set points at different times of the day. This thermostat shall include the capability to set back or temporarily operate the system to maintain zone temperatures down to 55°F (13°C) or up to 85°F (29°C). The thermostat shall initially be programmed by the manufacturer with a heating temperature set point no higher than 70°F (21°C) and a cooling temperature set point no lower than 78°F (26°C).

N1103.1.2 (R403.1.2) Heat Pump Supplementary Heat (Mandatory)

AMENDMENT
This section has been amended at the state or city level.
Heat pumps having supplementary electric-resistance heat shall have controls that, except during defrost, prevent supplemental heat operation when the heat pump compressor can meet the heating load.

     A heat strip outdoor temperature lockout thermostat shall be provided to prevent supplemental heat operation in response to the thermostat being changed to a warmer setting. The lockout shall be set no lower than 35°F (2°C) and no higher than 40°F (4°C).

Exceptions:
  1. In lieu of a heat strip outdoor temperature lockout thermostat, the following time and temperature electric-resistance control may be used. After six minutes of compressor run time in heat mode, supplemental electric heat shall energize only if the leaving air temperature from the indoor coil is below 90°F (32°C). If the indoor coil leaving air temperature exceeds 100°F (38°C), supplemental heat shall automatically de-energize, but allow the compressor to continue to operate until the call is satisfied. No thermostat shall initiate supplemental electric heat at any time. Thermostat controlled emergency heat shall not be limited by outdoor temperature. Electric resistance supplemental heat during defrost shall operate normally without limitation.
  2. In lieu of a heat strip outdoor temperature lockout thermostat, a programmable indoor thermostat with the capability to minimize the use of supplementary electrical resistance heat using an automatic temperature ramp up control feature shall be acceptable.
Hot water boilers that supply heat to the building through one- or two-pipe heating systems shall have an outdoor setback control that lowers the boiler water temperature based on the outdoor temperature.

N1103.3 (R403.3) Ducts

AMENDMENT
This section has been amended at the state or city level.
Ducts and air handlers shall be in accordance with Sections N1103.3.1 through N1103.3.4.

N1103.3.1 (R403.3.1) Insulation (Prescriptive) (Mandatory)

AMENDMENT
This section has been amended at the state or city level.
Supply and return ducts in unconditioned space and outdoors shall be insulated to a minimum R-8. Supply ducts inside semi-conditioned space shall be insulated to a minimum R-4; return ducts inside conditioned and semi-conditioned space are not required to be insulated. Ducts located inside conditioned space are not required to be insulated other than as may be necessary for preventing the formation of condensation on the exterior of cooling ducts.

N1103.3.2 (R403.3.2) Sealing (Mandatory)

AMENDMENT
This section has been amended at the state or city level.
Ducts, air handlers, filter boxes and building cavities used as ducts shall be sealed. Joints and seams shall comply with either the International Mechanical Code or Section M1601.4.1 of this code, as applicable.

Exceptions:
  1. Air-impermeable spray foam products shall be permitted to be applied without additional joint seals.

N1103.3.2.1 (R403.3.2.1) Sealed Air Handler

AMENDMENT
This section has been amended at the state or city level.

N1103.3.3 (R403.3.3) Duct Leakage (Prescriptive) and Duct Testing (Mandatory)

AMENDMENT
This section has been amended at the state or city level.


Duct testing and duct leakage shall be verified by compliance with either Section N1103.3.3.1 or N1103.3.3.2. Duct testing shall be performed and reported by the permit holder, a North Carolina licensed general contractor, a North Carolina licensed HVAC contractor, a North Carolina licensed Home Inspector, a registered design professional, a certified BPI envelope professional or a certified HERS rater. A single point depressurization, not temperature corrected, test is sufficient to comply with this provision, provided that the duct testing fan assembly(s) has been certified by the manufacturer to be capable of conducting tests in accordance with ASTM E1554-07.

     The duct leakage information, including duct leakage test selected and result, tester name, date, and contact information, shall be included on the certificate described in Section N1101.14.

     For the Test Criteria, the report shall be produced in the following manner: perform the HVAC system air leakage test and record the CFM25. Calculate the total square feet of conditioned floor area (CFA) served by that system. Multiply CFM25 by 100, divide the result by the CFA and record the result. If the result is less than or equal to 5 CFM25/100SF for the "Total duct leakage" test or less than or equal to 4 CFM25/100SF for the "Duct leakage to the outside" test, then the HVAC system air tightness is acceptable. Appendix E-3C contains optional sample worksheets for duct testing for the permit holder's use only.

Exceptions:
  1. Duct systems or portions thereof inside the building thermal envelope shall not be required to be leak tested.
  2. Installation of a partial system as part of replacement, renovation or addition does not require a duct leakage test.
  3. Duct systems (complete) serving areas of 750 square feet or less shall not need to be required to be leak tested.

N1103.3.3.1 Total Duct Leakage

AMENDMENT
This section has been amended at the state or city level.
Total duct leakage shall be less than or equal to 5 CFM (141.6 L/min) per 100 square feet (9.29 m2) of conditioned floor area served by that system when tested at a pressure differential of 0.1 inches w.g. (25 Pa) across the entire system, including the manufacturer's air handler enclosure.

During testing:
  1. Block, if present, ventilation air duct(s) connected to the conditioning system.
  2. The duct air leakage testing equipment shall be attached to the largest return in the system or to the air handler.
  3. The filter shall be removed and the air handler power shall be turned off.
  4. Supply boots or registers and return boxes or grilles shall be taped, plugged, or otherwise sealed air tight.
  5. The hose for measuring the 25 Pascals of pressure differential shall be inserted into the boot of the supply that is nominally closest to the air handler.
  6. Specific instructions from the duct testing equipment manufacturer shall be followed to reach duct test pressure and measure duct air leakage.

N1103.3.3.2 Duct Leakage to the Outside

AMENDMENT
This section has been amended at the state or city level.
Conduct the test using fan pressurization of distribution system and building at a fixed reference pressure for combined supply and return leak. Duct leakage to the outside shall be less than or equal to 4 CFM (113.3 L/min) per 100 square feet (9.29 m2) of conditioned floor area served by that system when tested at a pressure differential of 0.1 inches w.g. (25 Pa) across the entire system, relative to the outside, including the manufacturer's air handler enclosure.

During testing:
  1. Block, if present, the ventilation air duct(s) connected to the conditioning system.
  2. The duct air leakage testing equipment shall be attached to the largest return in the system or to the air handler.
  3. The filter shall be removed and the air handler power shall be turned off.
  4. Supply boots or registers and return boxes or grilles shall be taped, plugged, or otherwise sealed air tight or as tight as possible.
  5. The hose for measuring the 25 Pascals of pressure differential shall be inserted into the boot of the supply that is nominally closest to the air handler.
  6. Open all interconnecting doors in the building, close dampers for fireplaces and other operable dampers.
  7. Set up an envelope air moving/flow-regulating/flow measurement assembly, such as a blower door, following the manufacturer's prescribed procedure.
  8. Specific instructions from the duct testing equipment manufacturer shall be followed to reach duct test pressure and measure duct air leakage used in combination with a blower door. Typical steps are as follows:
    1. Depressurize the ductwork system to 25 Pa using the measurement hose in Step 5.
    2. Depressurize the house to 25 Pa using an envelope air moving/flow-regulating/flow measurement assembly, such as a blower door.
    3. Correct the duct pressure to measure 0 Pa of pressure differential between the house and the ductwork system.
    4. Read the CFM of duct leakage using the procedures for the specific equipment being used. (Note that most automatically calculating pressure gauges cannot compute the CFM25 automatically with a ductto-house difference in pressure of 0 Pa, so the gauge setting should be set to read CFM instead of CFM25).

N1103.3.4 (R403.3.4) Duct Leakage (Prescriptive)

AMENDMENT
This section has been amended at the state or city level.

N1103.3.5 N1103.3.4 (R403.3.5) (R403.3.4) Building Cavities (Mandatory)

AMENDMENT
This section has been amended at the state or city level.
Building framing cavities shall not be used as supply ducts or supply plenums.
Mechanical system piping capable of carrying fluids above 105°F (41°C) or below 55°F (13°C) shall be insulated to a minimum of R-3.

N1103.4.1 (R403.4.1) Protection of Piping Insulation

AMENDMENT
This section has been amended at the state or city level.

N1103.5 (R403.5) Service Hot Water Systems

AMENDMENT
This section has been amended at the state or city level.
All circulating service hot water piping shall be insulated to at least R-2. Circulating hot water systems shall include an automatic or readily accessible manual switch that can turn off the hot water circulating pump when the system is not in use.

N1103.5.1 (R403.5.1) Heated Water Circulation and Temperature Maintenance Systems (Mandatory)

AMENDMENT
This section has been amended at the state or city level.

N1103.5.1.1 (R403.5.1.1) Circulation Systems

AMENDMENT
This section has been amended at the state or city level.

N1103.5.1.2 (R403.5.1.2) Heat Trace Systems

AMENDMENT
This section has been amended at the state or city level.

N1103.5.2 (R403.5.2) Demand Recirculation Systems

AMENDMENT
This section has been amended at the state or city level.

N1103.5.3 (R403.5.3) Hot Water Pipe Insulation (Prescriptive)

AMENDMENT
This section has been amended at the state or city level.

N1103.5.4 (R403.5.4) Drain Water Heat Recovery Units

AMENDMENT
This section has been amended at the state or city level.
The building shall be provided with ventilation that meets the requirements of Section M1507 of this code or the International Mechanical Code, as applicable, or with other approved means of ventilation. Outdoor air intakes and exhausts shall have automatic or gravity dampers that close when the ventilation system is not operating.

N1103.6.1 (R403.6.1) Whole-House Mechanical Ventilation System Fan Efficacy

AMENDMENT
This section has been amended at the state or city level.

N1103.7 (R403.7) Equipment Sizing and Efficiency Rating (Mandatory)

AMENDMENT
This section has been amended at the state or city level.
Heating and cooling equipment shall be sized in accordance with ACCA Manual S based on building loads calculated in accordance with ACCA Manual J or other approved heating and cooling calculation methodologies. New heating and cooling equipment shall have an efficiency rating equal to or greater than the minimum required by federal law for the geographic location where the equipment is installed.

N1103.8 (R403.8) Systems Serving Multiple Dwelling Units (Mandatory)

AMENDMENT
This section has been amended at the state or city level.
Building mechanical systems and service water heating systems serving multiple dwelling units shall comply with Sections C403 and C404 of the IECC—Commercial Provisions in lieu of Section N1103.

N1103.9 (R403.9) Snow Melt System Controls (Mandatory)

AMENDMENT
This section has been amended at the state or city level.
Snow- and ice-melting systems, supplied through energy service to the building, shall include automatic controls capable of shutting off the system when the pavement temperature is above 50°F (10°C).
The energy consumption of pools and permanent spas shall be in accordance with Sections N1103.10.1 through N1103.10.3.

N1103.10.1 (R403.10.1) Heaters

AMENDMENT
This section has been amended at the state or city level.
All heaters shall be equipped with a readily accessible on-off switch that is mounted outside of the heater to allow shutting off the heater without adjusting the thermostat setting. Gas-fired heaters shall not be equipped with constantly burning pilot lights.
Time switches or other control methods that can automatically turn off and on according to a preset schedule shall be installed for heaters and pump motors. Heaters and pump motors that have built-in time switches shall be in compliance with this section.

Exceptions:
  1. Where public health standards require 24-hour pump operation.
  2. Pumps that operate solar- and waste-heat-recovery pool heating systems.

N1103.10.3 (R403.10.3) Covers

AMENDMENT
This section has been amended at the state or city level.
Outdoor heated pools and outdoor permanent spas shall be provided with a Class 1 vapor-retardant cover.

Exception: Pools deriving over 70 percent of the energy from heating from a site-recovered energy or solar energy source.

N1103.11 (R403.11) Portable Spas (Mandatory)

AMENDMENT
This section has been amended at the state or city level.
Residential swimming pools and permanent residential spas that are accessory to detached one- and two-family dwellings and townhouses 3 stories or less in height above grade plane and that are available only to the household and its guests shall be in accordance with APSP-15.
Not less than 75 percent of the lamps in permanently installed lighting fixtures shall be high-efficacy lamps or not less than 75 percent of the permanently installed lighting fixtures shall contain only high-efficacy lamps.

Exception: Low-voltage lighting.
Fuel gas lighting systems shall not have continuously burning pilot lights.

N1105.1 (R405.1) Scope

AMENDMENT
This section has been amended at the state or city level.
This section establishes criteria for compliance using simulated energy performance analysis. Such analysis shall include those items identified in Table N1105.5.2(1), as applicable. A registered design professional is required to perform the analysis if required by North Carolina licensure laws.

N1105.2 (R405.2) Mandatory Requirements

AMENDMENT
This section has been amended at the state or city level.
Compliance with this section requires that the mandatory provisions identified in Section N1101.13(2) be met.
Compliance based on simulated energy performance requires that a proposed residence (proposed design) be shown to have an annual energy cost that is less than or equal to the annual energy cost of the standard reference design. Energy prices shall be taken from a source approved by the building official, such as the Department of Energy, Energy Information Administration's State Energy Price and Expenditure Report. Building officials shall be permitted to require time-of-use pricing in energy cost calculations.

Exception: The energy use based on source energy expressed in Btu (J) or Btu per square foot (J/m2) of conditioned floor area shall be permitted to be substituted for the energy cost. The source energy multiplier for electricity shall be 3.16. The source energy multiplier for fuels other than electricity shall be 1.1.
Documentation of the software used for the performance design and the parameters for the building shall be in accordance with Sections N1105.4.1 through N1105.4.3.
Documentation verifying that the methods and accuracy of the compliance software tools conform to the provisions of this section shall be provided to the building official.

N1105.4.2 (R405.4.2) Compliance Report

AMENDMENT
This section has been amended at the state or city level.
Compliance software tools shall generate a report that documents that the proposed design complies with Section N1105.3. A compliance report on the proposed design shall be submitted. A compliance report shall include the following:
  1. Building street address, or other building site identification.
  2. A statement indicating that the proposed design complies with Section N1105.3.
  3. An inspection checklist documenting the building component characteristics of the proposed design as indicated in Table N1105.5.2(1). The inspection checklist shall show results for both the standard reference design and the proposed design with user inputs to the compliance software to generate the results.
  4. A site-specific energy analysis report that is in compliance with Section N1105.3.
  5. The name of the individual performing the analysis and generating the report.
  6. The name and version of the compliance software tool.

N1105.4.2.1 (R405.4.2.1) Compliance Report for Permit Application

AMENDMENT
This section has been amended at the state or city level.

N1105.4.2.2 (R405.4.2.2) Compliance Report for Certificate of Occupancy

AMENDMENT
This section has been amended at the state or city level.
The building official shall be permitted to require the following documents:
  1. Documentation of the building component characteristics of the standard reference design.
  2. A certification signed by the builder providing the building component characteristics of the proposed design as given in Table N1105.5.2(1).
  3. Documentation of the actual values used in the software calculations for the proposed design.
Calculations of the performance design shall be in accordance with Sections N1105.5.1 and N1105.5.2.
Except as specified by this section, the standard reference design and proposed design shall be configured and analyzed using identical methods and techniques.

N1105.5.2 (R405.5.2) Residence Specifications

AMENDMENT
This section has been amended at the state or city level.
The standard reference design and proposed design shall be configured and analyzed as specified by Table N1105.5.2(1). Table N1105.5.2(1) shall include, by reference, all notes contained in Table N1102.1.2.

TABLE N1105.5.2(1) [R405.5.2(1)]
SPECIFICATIONS FOR THE STANDARD REFERENCE AND PROPOSED DESIGNS
BUILDING COMPONENT STANDARD REFERENCE DESIGN PROPOSED DESIGN
Above-grade walls Type: mass wall if proposed wall is mass; otherwise wood frame. As proposed
Gross area: same as proposed As proposed
U-factor: as specified in Table N1102.1.4 As proposed
Solar absorptance = 0.75 As proposed
Emittance = 0.90 As proposed
Basement and crawl space walls Type: same as proposed As proposed
Gross area: same as proposed As proposed
U-factor: from Table N1102.1.4, with insulation layer on interior side of walls As proposed
Above-grade floors Type: wood frame As proposed
Gross area: same as proposed As proposed
U-factor: as specified in Table N1102.1.4 As proposed
Ceilings Type: wood frame As proposed
Gross area: same as proposed As proposed
U-factor: as specified in Table N1102.1.4 As proposed
Roofs Type: composition shingle on wood sheathing As proposed
Gross area: same as proposed As proposed
Solar absorptance = 0.75 As proposed
Emittance = 0.90 As proposed
Attics Type: vented with aperture = 1 ft2 per 300 ft2 ceiling area As proposed
Foundations Type: same as proposed As proposed
Foundation wall area above and below grade and soil characteristics: same as
proposed
As proposed
Opaque doors Area: 40 ft2 As proposed
Orientation: North As proposed
U-factor: same as fenestration from Table N1102.1.4 As proposed
Vertical fenestration
other than opaque doors
Total areah = As proposed
(a) The proposed glazing area, where the proposed glazing area is less than 15
percent of the conditioned floor area
(b) 15 percent of the conditioned floor area, where the proposed glazing area is
15 percent or more of the conditioned floor area
Orientation: equally distributed to four cardinal compass orientations
(N, E, S & W).
As proposed
U-factor: as specified in Table N1102.1.4 As proposed
SHGC: as specified in Table N1102.1.2 except that for climates with no requirement
(NR) SHGC = 0.40 shall be used.
As proposed
Interior shade fraction: 0.92-(0.21 × SHGC for the standard reference design) 0.92-(0.21 × SHGC as proposed)
External shading: none As proposed
Skylights None As proposed
Thermally isolated
sunrooms
None As proposed
Air exchange rate Air leakage rate of 5 air changes per hour in Climate Zones 3 through 5 at a pressure of 0.2 inches w.g (50 Pa). The mechanical ventilation rate shall be in addition to the air leakage rate and the same as in the proposed design, but no greater than 0.01 × CFA + 7.5 × (Nbr + 1)
where:
CFA = conditioned floor area
Nbr = number of bedrooms
Energy recovery shall not be assumed for mechanical ventilation.
For residences that are not
tested, the same air leakage rate
as the standard reference design.
For tested residences, the measured
air exchange ratea.
The mechanical ventilation rateb
shall be in addition to the air
leakage rate and shall be as proposed.
Mechanical ventilation None, except where mechanical ventilation is specified by the proposed
design, in which case:
Annual vent fan energy use:
kWh/yr = 0.03942 × CFA + 29.565 × (Nbr +1)
where:
CFA = conditioned floor area
Nbr = number of bedrooms
As proposed
Internal gains IGain = 17,900 + 23.8 × CFA + 4104 × Nbr (Btu/day per dwelling unit) Same as standard reference design.
Internal mass An internal mass for furniture and contents of 8 pounds per square foot of
floor area.
Same as standard reference design,
plus any additional mass specifically
designed as a thermal storage
elementc but not integral to the
building envelope or structure.
Structural mass For masonry floor slabs, 80 percent of floor area covered by R-2 carpet and
pad, and 20 percent of floor directly exposed to room air.
As proposed
For masonry basement walls, as proposed, but with insulation required by
Table N1102.1.4 located on the interior side of the walls
As proposed
For other walls, for ceilings, floors, and interior walls, wood frame
construction
As proposed
Heating systemsd, e As proposed for other than electric heating without a heat pump, where the
proposed design utilizes electric heating without a heat pump the standard
reference design shall be an air source heat pump meeting the requirements
of Section C403 of the IECC-Commercial Provisions.
Capacity: sized in accordance with Section N1103.7
As proposed
Cooling systemsd, f As proposed
Capacity: sized in accordance with Section N1103.7.
As proposed
Service water heatingd, e, f As proposed
Use: same as proposed design
As proposed
gal/day = 30 + (10 × Nbr)
Thermal distribution
systems
Duct insulation: From Section N1103.3.1
A thermal distribution system efficiency (DSE) of 0.88 shall be applied to
both the heating and cooling system efficiencies for all systems other than
tested duct systems. For tested duct systems, the leakage rate shall be 4 cfm
(113.3 L/min) per 100 ft2 (9.29 m2) of conditioned floor area at a pressure
of differential of 0.1 inches w.g. (25 Pa).
As tested or as specified in Table N1105.5.2(2) if not tested. Duct insulation shall be the same as standard reference design.
Thermostat Type: Manual, cooling temperature setpoint = 75°F;
Heating temperature setpoint = 72°F
Same as standard reference

For SI: 1 square foot = 0.93 m2, 1 British thermal unit = 1055 J, 1 pound per square foot = 4.88 kg/m2, 1 gallon (US) = 3.785 L, °C = (°F-32)/1.8, 1 degree = 0.79 rad.
a. Where required by the code official, testing shall be conducted by an approved party. Hourly calculations as specified in the ASHRAE Handbook of Fundamentals, or the equivalent shall be used to determine the energy loads resulting from infiltration.
b. The combined air exchange rate for infiltration and mechanical ventilation shall be determined in accordance with Equation 43 of 2001 ASHRAE Handbook of Fundamentals, page 26.24 and the "Whole-house Ventilation" provisions of 2001 ASHRAE Handbook of Fundamentals, page 26.19 for intermittent mechanical ventilation.
c. Thermal storage element shall mean a component not part of the floors, walls or ceilings that is part of a passive solar system, and that provides thermal storage such as enclosed water columns, rock beds, or phase-change containers. A thermal storage element must be in the same room as fenestration that faces within 15 degrees (0.26 rad) of true south, or must be connected to such a room with pipes or ducts that allow the element to be actively charged.
d. For a proposed design with multiple heating, cooling or water heating systems using different fuel types, the applicable standard reference design system capacities and fuel types shall be weighted in accordance with their respective loads as calculated by accepted engineering practice for each equipment and fuel type present.
e. For a proposed design without a proposed heating system, a heating system with the prevailing federal minimum efficiency shall be assumed for both the standard reference design and proposed design.
f. For a proposed design home without a proposed cooling system, an electric air conditioner with the prevailing federal minimum efficiency shall be assumed for both the standard reference design and the proposed design.
g. For a proposed design with a nonstorage-type water heater, a 40-gallon storage-type water heater with the prevailing federal minimum energy factor for the same fuel as the predominant heating fuel type shall be assumed. For the case of a proposed design without a proposed water heater, a 40-gallon storage-type water heater with the prevailing federal minimum efficiency for the same fuel as the predominant heating fuel type shall be assumed for both the proposed design and standard reference design.
h. For residences with conditioned basements, R-2 and R-4 residences and townhouses, the following formula shall be used to determine glazing area:
AF = As × FA × F
where:
AF = Total glazing area.
As = Standard reference design total glazing area.
FA = (Above-grade thermal boundary gross wall area)/(above-grade boundary wall area + 0.5 × below-grade boundary wall area).
F = (Above-grade thermal boundary wall area)/(above-grade thermal boundary wall area + common wall area) or 0.56, whichever is greater.
and where:
Thermal boundary wall is any wall that separates conditioned space from unconditioned space or ambient conditions.
Above-grade thermal boundary wall is any thermal boundary wall component not in contact with soil.
Below-grade boundary wall is any thermal boundary wall in soil contact.
Common wall area is the area of walls shared with an adjoining dwelling unit.
L and CFA are in the same units.


TABLE N1105.5.2(2) [R405.5.2(2)]
DEFAULT DISTRIBUTION SYSTEM EFFICIENCIES FOR PROPOSED DESIGNSa
DISTRIBUTION SYSTEM CONFIGURATION AND CONDITION FORCED AIR SYSTEMS HYDRONIC SYSTEMSb
Distribution system components located in unconditioned space 0.95
Untested distribution systems entirely located in conditioned spacec 0.88 1
"Ductless" systemsd 1

For SI: 1 cubic foot per minute = 0.47 L/s, 1 square foot = 0.093m2, 1 pound per square inch = 6895 Pa, 1 inch water gauge = 1250 Pa.
a. Default values given by this table are for untested distribution systems, which must still meet minimum requirements for duct system insulation.
b. Hydronic systems shall mean those systems that distribute heating and cooling energy directly to individual spaces using liquids pumped through closed-loop piping and that do not depend on ducted, forced airflow to maintain space temperatures.
c. Entire system in conditioned space shall mean that no component of the distribution system, including the air handler unit, is located outside of the conditioned space.
d. Ductless systems shall be allowed to have forced airflow across a coil but shall not have any ducted airflow external to the manufacturer's air handler enclosure.
Calculation software, where used, shall be in accordance with Sections N1105.6.1 through N1105.6.3.
Calculation procedures used to comply with this section shall be software tools capable of calculating the annual energy consumption of all building elements that differ between the standard reference design and the proposed design and shall include the following capabilities:
  1. Computer generation of the standard reference design using only the input for the proposed design. The calculation procedure shall not allow the user to directly modify the building component characteristics of the standard reference design.
  2. Calculation of whole-building (as a single zone) sizing for the heating and cooling equipment in the standard reference design residence in accordance with Section N1103.6.
  3. Calculations that account for the effects of indoor and outdoor temperatures and part-load ratios on the performance of heating, ventilating and air-conditioning equipment based on climate and equipment sizing.
  4. Printed building official inspection checklist listing each of the proposed design component characteristics from Table N1105.5.2(1) determined by the analysis to provide compliance, along with their respective performance ratings (R-value, U-factor, SHGC, HSPF, AFUE, SEER, EF are some examples).
Performance analysis tools meeting the applicable provisions of Section N1105 shall be permitted to be approved. Tools are permitted to be approved based on meeting a specified threshold for a jurisdiction. The building official shall be permitted to approve tools for a specified application or limited scope.
When calculations require input values not specified by Sections N1102, N1103, N1104 and N1105, those input values shall be taken from an approved source.
This section establishes criteria for compliance using an Energy Rating Index (ERI) analysis.

N1106.2 (R406.2) Mandatory Requirements

AMENDMENT
This section has been amended at the state or city level.
Compliance with this section requires that the provisions identified in Sections N1101 through N1104 labeled as "mandatory" be met. The building thermal envelope shall be greater than or equal to levels of efficiency and Solar Heat Gain Coefficient in Table 1102.1.1 or 1102.1.3 of the 2012 NC Energy Conservation Code. Minimum standards associated with compliance shall be the ANSI RESNET ICC Standard 301-2014 "Standard for the Calculation and Labeling of the Energy Performance of Low-Rise Residential Buildings using an Energy Rating Index." A North Carolina licensed design professional or certified HERS rater is required to perform the analysis if required by North Carolina licensure laws.

Exception: Supply and return ducts in unconditioned space and outdoors shall be insulated to a minimum R-8. Supply ducts inside semi-conditioned space shall be insulated to a minimum R-4; return ducts inside conditioned and semi-conditioned space are not required to be insulated. Ducts located inside conditioned space are not required to be insulated other than as may be necessary for preventing the formation of condensation on the exterior of cooling ducts.
The Energy Rating Index (ERI) shall be a numerical integer value that is based on a linear scale constructed such that the ERI reference design has an Index value of 100 and a residential building that uses no net purchased energy has an Index value of 0. Each integer value on the scale shall represent a 1 percent change in the total energy use of the rated design relative to the total energy use of the ERI reference design. The ERI shall consider all energy used in the residential building.
The ERI reference design shall be configured such that it meets the minimum requirements of the 2006 International Energy Conservation Code prescriptive requirements.

The proposed residential building shall be shown to have an annual total normalized modified load less than or equal to the annual total loads of the ERI reference design.

N1106.4 (R406.4) ERI-Based Compliance

AMENDMENT
This section has been amended at the state or city level.
Compliance based on an ERI analysis requires that the rated design be shown to have an ERI less than or equal to the appropriate value listed in Table N1106.4.1 or Table N1106.4.2, as applicable, when compared to the ERI reference design.

TABLE N1106.4.1 (R406.4.1)
MAXIMUM ENERGY RATING INDEX (without calculation of on-site renewable energy)
CLIMATE ZONE JAN. 1, 2019 —
DEC. 31, 2022
JAN. 1, 2023
AND FORWARD
3 65 61
4 67 63
5 67 63


TABLE N1106.4.2 (R406.4.2)
MAXIMUM ENERGY RATING INDEX (without calculation of on-site renewable energy)
CLIMATE ZONE JAN. 1, 2019 —
DEC. 31, 2022
JAN. 1, 2023
AND FORWARD
3 51 47
4 54 50
5 55 51

N1106.5 (R406.5) Verification by Approved Agency

AMENDMENT
This section has been amended at the state or city level.
Verification of compliance with Section N1106 shall be performed by the licensed design professional or certified HERS rater and the compliance documentation shall be provided to the code official. The code official shall inspect according to the requirements of Section N1106.6.2.
Documentation of the software used to determine the ERI and the parameters for the residential building shall be in accordance with Sections N1106.6.1 through N1106.6.3.

N1106.6.1 (R406.6.1) Compliance Software Tools

AMENDMENT
This section has been amended at the state or city level.
Compliance software tools for this section shall be in compliance with ANSI/RESNET/ICC 301—2014.

N1106.6.2 (R406.6.2) Compliance Report

AMENDMENT
This section has been amended at the state or city level.
Compliance software tools shall generate a report that documents that the ERI of the rated design complies with Sections N1106.3 and N1106.4. The compliance documentation shall include the following information:
  1. Address or other identification of the residential building.
  2. An inspection checklist documenting the building component characteristics of the rated design. The inspection checklist shall show results for both the ERI reference design and the rated design, and shall document all inputs entered by the user necessary to reproduce the results.
  3. Name of individual completing the compliance report.
  4. Name and version of the compliance software tool.

N1106.6.3 (R406.6.3) Additional Documentation

AMENDMENT
This section has been amended at the state or city level.
Calculation software, where used, shall be in accordance with Sections N1106.7.1 through N1106.7.3.

N1106.7.1 (R406.7.1) Minimum Capabilities

AMENDMENT
This section has been amended at the state or city level.
Calculation procedures used to comply with this section shall be software tools capable of calculating the ERI as described in Section N1106.3 and shall be in compliance with ANSI/RESNET/ICC 301, and the software shall include the following capabilities:
  1. Computer generation of the ERI reference design using only the input for the rated design.

         The calculation procedure shall not allow the user to directly modify the building component characteristics of the ERI reference design.
  2. Calculation of whole-building, as a single zone, sizing for the heating and cooling equipment in the ERI reference design residence in accordance with Section N1103.7.
  3. Calculations that account for the effects of indoor and outdoor temperatures and part-load ratios on the performance of heating, ventilating and air-conditioning equipment based on climate and equipment sizing.
  4. Printed code official inspection checklist listing each of the rated design component characteristics determined by the analysis to provide compliance, along with their respective performance ratings.

N1106.7.2 (406.7.2) Specific Approval

AMENDMENT
This section has been amended at the state or city level.

N1106.7.3 (R406.7.3) Input Values

AMENDMENT
This section has been amended at the state or city level.
The provisions of Sections N1107 through N1111 shall control the alteration, repair, addition and change of occupancy of existing buildings and structures.
Additions, alterations, or repairs to an existing building, building system or portion thereof shall comply with Section N1108, N1109 or N1110. Unaltered portions of the existing building or building supply system shall not be required to comply with this chapter.
Except as specified in this chapter, this code shall not be used to require the removal, alteration or abandonment of, nor prevent the continued use and maintenance of, an existing building or building system lawfully in existence at the time of adoption of this code.

N1107.3 (R501.3) Maintenance

AMENDMENT
This section has been amended at the state or city level.

N1107.4 (R501.4) Compliance

AMENDMENT
This section has been amended at the state or city level.
Alterations, repairs, additions and changes of occupancy to, or relocation of, existing buildings and structures shall comply with the provisions for alterations, repairs, additions and changes of occupancy or relocation, respectively, in this code and the International Building Code, International Fire Code, International Fuel Gas Code, International Mechanical Code, International Plumbing Code, North Carolina Existing Building Code and NFPA 70.
Except as otherwise required or permitted by this code, materials permitted by the applicable code for new construction shall be used. Like materials shall be permitted for repairs, provided no hazard to life, health or property is created. Hazardous materials shall not be used where the code for new construction would not permit their use in buildings of similar occupancy, purpose and location.

N1107.6 (R501.6) Historic Buildings

AMENDMENT
This section has been amended at the state or city level.
No provision of this chapter relating to the construction, repair, alteration, restoration and movement of structures, and change of occupancy shall be mandatory for historic buildings.
Additions to an existing building, building system or portion thereof shall conform to the provisions of this chapter as they relate to new construction without requiring the unaltered portion of the existing building or building system to comply with this chapter. Additions shall not create an unsafe or hazardous condition or overload existing building systems. An addition shall be deemed to comply with this chapter where the addition alone complies, where the existing building and addition comply with this chapter as a single building, or where the building with the addition uses no more energy than the existing building. Additions shall be in accordance with Section N1108.1.1 or N1108.1.2.

N1108.1.1.1 (R502.1.1.1) Building Envelope

AMENDMENT
This section has been amended at the state or city level.
New building thermal envelope assemblies that are part of the addition shall comply with Sections N1102.1, N1102.2, N1102.3.1 through N1102.3.5, and N1102.4.

N1108.1.1.2 (R502.1.1.2) Heating and Cooling Systems

AMENDMENT
This section has been amended at the state or city level.
New heating, cooling and duct systems that are part of the addition shall comply with Sections N1103.1, N1103.2, N1103.3, N1103.4 and N1103.6. New heating and cooling appliances shall be sized in accordance with Section N1103.7. Extensions of ducts from an existing system to a new addition shall require that the existing system be evaluated for the new design.

Exception: Installation of an addition to an existing duct system shall not require a duct leakage test.
New service hot water systems that are part of the addition shall comply with Section N1103.5.
New lighting systems that are part of the addition shall comply with Section N1104.1.

N1108.1.2 (R502.1.2) Existing Plus Addition Compliance (Simulated Performance Alternative for Additions)

AMENDMENT
This section has been amended at the state or city level.
The addition shall comply with Section N1105, as applicable.

N1109.1 (R503.1) General

AMENDMENT
This section has been amended at the state or city level.
Alterations to an existing building, building system or portion thereof shall conform to the provisions of this chapter as they relate to new construction without requiring the unaltered portions of the existing building or building system to comply with this chapter. Alterations shall not create an unsafe or hazardous condition or overload existing building systems. Alterations to existing buildings shall comply with Sections N1109.1.1 through N1109.2.

N1109.1.1 (R503.1.1) Building Envelope

AMENDMENT
This section has been amended at the state or city level.
Building envelope assemblies that are part of the alteration shall comply with Section N1102 or N1102.1.4, Sections N1102.2.1 through N1102.2.15, N1102.3.1, N1102.3.2, N1102.4.4 and N1102.4.6.

Exception: The following alterations to conditioned spaces need not comply with the requirements for new construction:
  1. Storm windows installed over existing fenestration.
  2. Existing ceiling, wall or floor cavities exposed during construction provided that these cavities are filled with insulation. Roof systems requiring air space for ventilation shall retain the ventilation space required.
  3. Construction where the existing roof, wall or floor cavity is not exposed.
  4. Roof recover and roof replacement such that the existing building or structure is no less conforming to the provisions of this code than the existing building or structure was prior to the alteration..
  5. Deleted.
  6. Surface applied window film installed on existing single pane fenestration assemblies to reduce solar heat gain.
  7. Converting unconditioned attic space to conditioned attic space for one- and two-family dwellings and townhouses. Ceilings shall be insulated to a minimum of R-30, walls shall be insulated to the exterior wall requirements in Table N1102.1.2 or Table N1102.1.4 and follow the backing requirements in Sections N1102.2.14 and N1102.2.15.

N1109.1.1.1 (R503.1.1.1) Replacement Fenestration

AMENDMENT
This section has been amended at the state or city level.
Where an entire existing fenestration unit is replaced with a new fenestration product, including frame, sash and glazing, the replacement fenestration unit shall meet the applicable requirements for U-factor and SHGC in Table N1102.1.2.

Exception: Alterations that replace less than 50 percent of entire fenestration units may be replaced with like or better fenestration units to match existing fenestration assemblies.

N1109.1.2 (R503.1.2) Heating and Cooling Systems

AMENDMENT
This section has been amended at the state or city level.
New heating, cooling and duct systems that are part of the alteration shall comply with Sections N1103.1, N1103.2, N1103.3, N1103.4, N1103.6 and N1103.7.

Exception: An alteration involving a partial system replacement to an existing duct system shall not require a duct leakage test.
New service hot water systems that are part of the alteration shall comply with Section N1103.5.
New lighting systems that are part of the alteration shall comply with Section N1104.1.

Exception: Alterations that replace less than 50 percent of the luminaires in a space, provided that such alterations do not increase the installed interior lighting power.

N1109.2 (R503.2) Change in Space Conditioning

AMENDMENT
This section has been amended at the state or city level.
In addition to the requirements of Section N1109.1, projects changing unconditioned space to conditioned space and costing more than $10,000 shall require 10 percent of the project cost to be used toward meeting the requirements of this chapter. Project costs for the purpose of this section is the total project cost listed on all permits related to the work required to convert the unconditioned space to conditioned space and excludes the 10 percent added from this section. Under this section, existing building envelope elements that become a part of the building thermal envelope and are not changed are not required to be upgraded. The additional 10 percent of the project cost shall be appropriated for additional energy conservation features of choice that are addressed in this chapter. In addition to the 10-percent project cost, any existing wall, ceiling, or floor cavities that are exposed during construction shall at a minimum be insulated to comply with this chapter or be insulated to fill the cavity, whichever is less. Roof systems requiring air space for ventilation shall retain the ventilation space required. Projects costing less than $10,000 are not subject to the 10-percent project cost addition provision.

N1110.1 (R504.1) General

AMENDMENT
This section has been amended at the state or city level.
Repair of the building systems shall not make the building less conforming than it was before the repair was undertaken. Work on nondamaged components necessary for the required repair of damaged components shall be considered part of the repair and shall not be subject to the requirements for alterations in this chapter.

N1110.2 (R504.2) Application Materials

AMENDMENT
This section has been amended at the state or city level.

Portions of walls that are part of the building thermal envelope shall be insulated in accordance with this code when the repair requires the removal of either the interior or exterior wall membrane such that the wall cavity is exposed during the repair.
Exception: Wall cavities containing existing insulation material.

N1110.3 (R504.3) Glazing

AMENDMENT
This section has been amended at the state or city level.
Repairs requiring the replacement of individual glass panes or sashes shall not require compliance with this code.

N1111.1 (R505.1) General

AMENDMENT
This section has been amended at the state or city level.
Alterations performed in spaces undergoing a change in occupancy shall comply with the requirements of this code. Unaltered portions of the existing building or building supply system shall not be required to comply with this code.

N1111.2 (R505.2) General

AMENDMENT
This section has been amended at the state or city level.
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