CODES

ADOPTS WITH AMENDMENTS:

International Residential Code 2012 (IRC 2012)

Copyright

Preface

Effective Use of the International Residential Code

Legislation

Chapter 1 Scope and Administration

Chapter 2 Definitions

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

Chapter 11 [Re] Energy Efficiency

Chapter 12 Mechanical Administration

Chapter 13 General Mechanical System Requirements

Chapter 14 Heating and Cooling Equipment and Appliances

Chapter 15 Exhaust Systems

Chapter 16 Duct Systems

Chapter 17 Combustion Air

Chapter 18 Chimneys and Vents

Chapter 19 Special Appliances, Equipment and Systems

Chapter 20 Boilers and Water Heaters

Chapter 21 Hydronic Piping

Chapter 22 Special Piping and Storage Systems

Chapter 23 Solar Energy Systems

Chapter 24 Fuel Gas

Chapter 25 Plumbing Administration

Chapter 26 General Plumbing Requirements

Chapter 27 Plumbing Fixtures

Chapter 28 Water Heaters

Chapter 29 Water Supply and Distribution

Chapter 30 Sanitary Drainage

Chapter 31 Vents

Chapter 32 Traps

Chapter 33 Storm Drainage

Chapter 34 General Requirements

Chapter 35 Electrical Definitions

Chapter 36 Services

Chapter 37 Branch Circuit and Feeder Requirements

Chapter 38 Wiring Methods

Chapter 39 Power and Lighting Distribution

Chapter 40 Devices and Luminaires

Chapter 41 Appliance Installation

Chapter 42 Swimming Pools

Chapter 43 Class 2 Remote-Control, Signaling and Power-Limited Circuits

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 Radon Control Methods

Appendix G Swimming Pools, Spas and Hot Tubs

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 Icc International Residential Code Electrical Provisions/National Electrical Code Cross Reference

This chapter regulates the energy efficiency for the design and construction of buildings regulated by this code.

Note: The text of the following Sections N1101.2 through N1105 is extracted from the 2012 edition of the International 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 International Energy Conservation Code—Residential Provisions.

This code shall regulate the design and construction of buildings for the effective use and conservation of energy over the useful life of each building. This code is intended to provide flexibility to permit the use of innovative approaches and techniques to achieve this objective. This code is not intended to abridge safety, health or environmental requirements contained in other applicable codes or ordinances.
Additions, alterations, renovations or repairs to an existing building, building system or portion thereof shall conform to the provisions of this code as they relate to new construction without requiring the unaltered portion(s) of the existing building or building system to comply with this code. Additions, alterations, renovations or repairs shall not create an unsafe or hazardous condition or overload existing building systems. An addition shall be deemed to comply with this code if the addition alone complies or if the existing building and addition comply with this code as a single building.
Exception: The following need not comply provided the energy use of the building is not increased:
1. Storm windows installed over existing fenestration.
2. Glass only replacements in an existing sash and frame.
3. Existing ceiling, wall or floor cavities exposed during construction provided that these cavities are filled with insulation.
4. Construction where the existing roof, wall or floor cavity is not exposed.
5. Reroofing for roofs where neither the sheathing nor the insulation is exposed. Roofs without insulation in the cavity and where the sheathing or insulation is exposed during reroofing shall be insulated either above or below the sheathing.
6. Replacement of existing doors that separate conditioned space from the exterior shall not require the installation of a vestibule or revolving door, provided, however, that an existing vestibule that separates a conditioned space from the exterior shall not be removed.
7. 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.
8. Alterations that replace only the bulb and ballast within the existing luminaires in a space provided that the alteration does not increase the installed interior lighting power.
Any nonconditioned space that is altered to become conditioned space shall be required to be brought into full compliance with this chapter.
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.
The following buildings, or portions thereof, separated from the remainder of the building by building thermal envelope assemblies complying with this code shall be exempt from the building thermal envelope provisions of this code:
1. Those with a peak design rate of energy usage less than 3.4 Btu/hft2 (10.7 W/m2) or 1.0 watt/ft2 (10.7 W/m2) of floor area for space conditioning purposes.
2. Those that do not contain conditioned space.
The building official or other authority having jurisdiction shall be permitted to deem a national, state or local energy-efficiency program to exceed the energy efficiency required by this code. Buildings approved in writing by such an energy-efficiency program shall be considered in compliance with this code. The requirements identified as “mandatory” in this chapter, as applicable, shall be met.
Construction documents shall be drawn to scale upon suitable material. Electronic media documents are permitted to be submitted when approved by the building official. Construction documents shall be of sufficient clarity to indicate the location, nature and extent of the work proposed, and show in sufficient detail pertinent data and features of the building, systems and equipment as herein governed. Details shall include, but are not limited to, as applicable, insulation materials and their R-values; fenestration U-factors and SHGCs; area-weighted U-factor and SHGC calculations; mechanical system design criteria; mechanical and service water heating system and equipment types, sizes and efficiencies; economizer description; equipment and systems controls; fan motor horsepower (hp) and controls; duct sealing, duct and pipe insulation and location; lighting fixture schedule with wattage and control narrative; and air sealing details.
The following words and terms shall, for the purposes of this chapter, have the meanings shown herein.
ABOVE-GRADE WALL. A wall more than 50 percent above grade and enclosing conditioned space. This includes between-floor spandrels, peripheral edges of floors, roof and basement knee walls, dormer walls, gable end walls, walls enclosing a mansard roof and skylight shafts.
ACCESSIBLE. Admitting close approach as a result of not being guarded by locked doors, elevation or other effective means (see “Readily accessible”).
ADDITION. An extension or increase in the conditioned space floor area or height of a building or structure.
AIR BARRIER. Material(s) assembled and joined together to provide a barrier to air leakage through the building envelope. An air barrier may be a single material or a combination of materials.
AUTOMATIC. Self-acting, operating by its own mechanism when actuated by some impersonal influence, as, for example, a change in current strength, pressure, temperature or mechanical configuration (see “Manual”).
BASEMENT WALL. A wall 50 percent or more below grade and enclosing conditioned space.
BUILDING. Any structure used or intended for supporting or sheltering any use or occupancy, including any mechanical systems, service water heating systems and electric power and lighting systems located on the building site and supporting the building.
BUILDING SITE. A continguous area of land that is under the ownership or control of one entity.
BUILDING THERMAL ENVELOPE. The basement walls, exterior walls, floor, roof, and any other building elements that enclose conditioned space or provides a boundary between conditioned space and exempt or unconditioned space.
C-FACTOR (THERMAL CONDUCTANCE). The coefficient of heat transmission (surface to surface) through a building component or assembly, equal to the time rate of heat flow per unit area and the unit temperature difference between the warm side and cold side surfaces (Btu/h ft2 °F) [W/(m2 K)].
CONDITIONED FLOOR AREA. The horizontal projection of the floors associated with the conditioned space.
CONDITIONED SPACE. An area or room within a building being heated or cooled, containing uninsulated ducts, or with a fixed opening directly into an adjacent conditioned space.
CONTINUOUS AIR BARRIER. A combination of materials and assemblies that restrict or prevent the passage of air through the building thermal envelope.
CRAWL SPACE WALL. The opaque portion of a wall that encloses a crawl space and is partially or totally below grade.
CURTAIN WALL. Fenestration products used to create an external nonload-bearing wall that is designed to separate the exterior and interior environments.
DEMAND RECIRCULATION WATER SYSTEM. A water distribution system where pump(s) prime the service hot water piping with heated water upon demand for hot water.
DUCT. A tube or conduit utilized for conveying air. The air passages of self-contained systems are not to be construed as air ducts.
DUCT SYSTEM. A continuous passageway for the transmission of air that, in addition to ducts, includes duct fittings, dampers, plenums, fans and accessory air-handling equipment and appliances.
ENERGY ANALYSIS. A method for estimating the annual energy use of the proposed design and standard reference design based on estimates of energy use.
ENERGY COST. The total estimated annual cost for purchased energy for the building functions regulated by this code, including applicable demand charges.
ENERGY SIMULATION TOOL. An approved software program or calculation-based methodology that projects the annual energy use of a building.
ENTRANCE DOOR. Fenestration products used for ingress, egress and access in nonresidential buildings, including, but not limited to, exterior entrances that utilize latching hardware and automatic closers and contain over 50-percent glass specifically designed to withstand heavy use and possibly abuse.
EXTERIOR WALL. Walls including both above-grade walls and basement walls.
FENESTRATION. Skylights, roof windows, vertical windows (fixed or moveable), opaque doors, glazed doors, glazed block and combination opaque/glazed doors. Fenestration includes products with glass and nonglass glazing materials.
FENESTRATION PRODUCT, SITE-BUILT. A fenestration designed to be made up of field-glazed or field-assembled units using specific factory cut or otherwise factory-formed framing and glazing units. Examples of site-built fenestration include storefront systems, curtain walls, and atrium roof systems.
HEATED SLAB. Slab-on-grade construction in which the heating elements, hydronic tubing, or hot air distribution system is in contact with, or placed within or under, the slab.
HIGH-EFFICACY LAMPS. Compact fluorescent lamps, T-8 or smaller diameter linear fluorescent lamps, or lamps with a minimum efficacy of:
1. 60 lumens per watt for lamps over 40 watts;
2. 50 lumens per watt for lamps over 15 watts to 40 watts; and
3. 40 lumens per watt for lamps 15 watts or less.
INFILTRATION. The uncontrolled inward air leakage into a building caused by the pressure effects of wind or the effect of differences in the indoor and outdoor air density or both.
INSULATING SHEATHING. An insulating board with a core material having a minimum R-value of R-2.
LOW-VOLTAGE LIGHTING. Lighting equipment powered through a transformer such as a cable conductor, a rail conductor and track lighting.
MANUAL. Capable of being operated by personal intervention (see “Automatic”).
PROPOSED DESIGN. A description of the proposed building used to estimate annual energy use for determining compliance based on total building performance.
READILY ACCESSIBLE. Capable of being reached quickly for operation, renewal or inspection without requiring those to whom ready access is requisite to climb over or remove obstacles or to resort to portable ladders or access equipment (see “Accessible”).
REPAIR. The reconstruction or renewal of any part of an existing building.
RESIDENTIAL BUILDING. For this code, includes detached one- and two-family dwellings and multiple single-family dwellings (townhouses) as well as Group R-2, R-3 and R-4 buildings three stories or less in height above grade plane.
R-VALUE (THERMAL RESISTANCE). The inverse of the time rate of heat flow through a body from one of its bounding surfaces to the other surface for a unit temperature difference between the two surfaces, under steady state conditions, per unit area (h ft2 °F/Btu) [(m2 K)/W].
SERVICE WATER HEATING. Supply of hot water for purposes other than comfort heating.
SKYLIGHT. Glass or other transparent or translucent glazing material installed at a slope of less than 60 degrees (1.05 rad) from horizontal. Glazing material in skylights, including unit skylights, solariums, sunrooms, roofs and sloped walls is included in this definition.
SOLAR HEAT GAIN COEFFICIENT (SHGC). The ratio of the solar heat gain entering the space through the fenestration assembly to the incident solar radiation. Solar heat gain includes directly transmitted solar heat and absorbed solar radiation which is then reradiated, conducted or convected into the space.
STANDARD REFERENCE DESIGN. A version of the proposed design that meets the minimum requirements of this code and is used to determine the maximum annual energy use requirement for compliance based on total building performance.
SUNROOM. A one-story structure attached to a dwelling with a glazing area in excess of 40 percent of the gross area of the structure's exterior walls and roof.
THERMAL ISOLATION. Physical and space conditioning separation from conditioned space(s). The conditioned space(s) shall be controlled as separate zones for heating and cooling or conditioned by separate equipment.
THERMOSTAT. An automatic control device used to maintain temperature at a fixed or adjustable set point.
U-FACTOR (THERMAL TRANSMITTANCE). The coefficient of heat transmission (air to air) through a building component or assembly, equal to the time rate of heat flow per unit area and unit temperature difference between the warm side and cold side air films (Btu/h ft2 °F) [W/(m2 K)].
VENTILATION AIR. That portion of supply air that comes from outside (outdoors) plus any recirculated air that has been treated to maintain the desired quality of air within a designated space.
VISIBLE TRANSMITTANCE [VT]. The ratio of visible light entering the space through the fenestration product assembly to the incident visible light, visible transmittance, includes the effects of glazing material and frame and is expressed as a number between 0 and 1.
WHOLE HOUSE MECHANICAL VENTILATION SYSTEM. An exhaust system, supply system, or combination thereof that is designed to mechanically exchange indoor air with outdoor air when operating continuously or through a programmed intermittent schedule to satisfy the whole house ventilation rates.
ZONE. A space or group of spaces within a building with heating or cooling requirements that are sufficiently similar so that desired conditions can be maintained throughout using a single controlling device.
Climate zones from Figure N1101.10 or Table N1101.10 shall be used in determining the applicable requirements in Sections N1101 through N1105. Locations not in Table N1101.10 (outside the United States) shall be assigned a climate zone based on Section N101.10.2.

FIGURE N1101.10 (R301.1)
CLIMATE ZONES

TABLE N1101.10 (R301.1)
CLIMATE ZONES, MOISTURE REGIMES, AND WARM-HUMID
DESIGNATIONS BY STATE, COUNTY AND TERRITORY

Key: A – Moist, B – Dry, C – Marine. Absence of moisture designation indicates moisture regime is irrelevant.
Asterisk (*) indicates a warm-humid location.

US STATES

ALABAMA3A Lee7 Kodiak Island 4A Boone3A Mississippi
3A Limestone7 Lake and3A Bradley3A Monroe
3A Autauga*3A Lowndes*Peninsula3A Calhoun3A Montgomery
2A Baldwin*3A Macon*7 Matanuska-4A Carroll3A Nevada
3A Barbour*3A MadisonSusitna3A Chicot4A Newton
3A Bibb3A Marengo*8 Nome3A Clark3A Ouachita
3A Blount3A Marion8 North Slope3A Clay3A Perry
3A Bullock*3A Marshall8 Northwest Arctic3A Cleburne3A Phillips
3A Butler*2A Mobile*7 Prince of Wales3A Cleveland3A Pike
3A Calhoun3A Monroe*Outer Ketchikan3A Columbia*3A Poinsett
3A Chambers3A Montgomery*7 Sitka3A Conway3A Polk
3A Cherokee3A Morgan7 Skagway-Hoonah-3A Craighead3A Pope
3A Chilton3A Perry*Angoon3A Crawford3A Prairie
3A Choctaw*3A Pickens8 Southeast3A Crittenden3A Pulaski
3A Clarke*3A Pike*Fairbanks3A Cross3A Randolph
3A Clay3A Randolph7 Valdez-Cordova3A Dallas3A Saline
3A Cleburne3A Russell*8 Wade Hampton3A Desha3A Scott
3A Coffee*3A Shelby7 Wrangell-3A Drew4A Searcy
3A Colbert3A St. ClairPetersburg3A Faulkner3A Sebastian
3A Conecuh*3A Sumter7 Yakutat3A Franklin3A Sevier*
3A Coosa3A Talladega8 Yukon-Koyukuk4A Fulton3A Sharp
3A Covington*3A TallapoosaARIZONA3A Garland3A St. Francis
3A Crenshaw*3A Tuscaloosa3A Grant4A Stone
3A Cullman3A Walker5B Apache3A Greene3A Union*
3A Dale*3A Washington*3B Cochise3A Hempstead*3A Van Buren
3A Dallas*3A Wilcox*5B Coconino3A Hot Spring4A Washington
3A DeKalb3A Winston4B Gila3A Howard3A White
3A Elmore*ALASKA3B Graham3A Independence3A Woodruff
3A Escambia*3B Greenlee4A Izard3A Yell
3A Etowah7 Aleutians East2B La Paz3A JacksonCALIFORNIA
3A Fayette7 Aleutians West2B Maricopa3A Jefferson
3A Franklin7 Anchorage3B Mohave3A Johnson3C Alameda
3A Geneva*8 Bethel5B Navajo3A Lafayette*6B Alpine
3A Greene7 Bristol Bay2B Pima3A Lawrence4B Amador
3A Hale7 Denali2B Pinal3A Lee3B Butte
3A Henry*8 Dillingham3B Santa Cruz3A Lincoln4B Calaveras
3A Houston*8 Fairbanks North4B Yavapai3A Little River*3B Colusa
3A JacksonStar2B Yuma3A Logan3B Contra Costa
3A Jefferson7 HainesARKANSAS3A Lonoke4C Del Norte
3A Lamar7 Juneau4A Madison4B El Dorado
3A Lauderdale7 Kenai Peninsula3A Arkansas4A Marion3B Fresno
3A Lawrence7 Ketchikan3A Ashley3A Miller*3B Glenn
Gateway4A Baxter
4A Benton

(continued)

TABLE N1101.10 (R301.1)—continued
CLIMATE ZONES, MOISTURE REGIMES, AND WARM-HUMID
DESIGNATIONS BY STATE, COUNTY AND TERRITORY

4C Humboldt3B Yuba5B Morgan2A Escambia*2A Taylor*
2B ImperialCOLORADO4B Otero2A Flagler*2A Union*
4B Inyo6B Ouray2A Franklin*2A Volusia*
3B Kern5B Adams7 Park2A Gadsden*2A Wakulla*
3B Kings6B Alamosa5B Phillips2A Gilchrist*2A Walton*
4B Lake5B Arapahoe7 Pitkin2A Glades*2A Washington*
5B Lassen6B Archuleta5B Prowers2A Gulf*GEORGIA
3B Los Angeles4B Baca5B Pueblo2A Hamilton*
3B Madera5B Bent6B Rio Blanco2A Hardee*2A Appling*
3C Marin5B Boulder7 Rio Grande2A Hendry*2A Atkinson*
4B Mariposa6B Chaffee7 Routt2A Hernando*2A Bacon*
3C Mendocino5B Cheyenne6B Saguache2A Highlands*2A Baker*
3B Merced7 Clear Creek7 San Juan2A Hillsborough*3A Baldwin
5B Modoc6B Conejos6B San Miguel2A Holmes*4A Banks
6B Mono6B Costilla5B Sedgwick2A Indian River*3A Barrow
3C Monterey5B Crowley7 Summit2A Jackson*3A Bartow
3C Napa6B Custer5B Teller2A Jefferson*3A Ben Hill*
5B Nevada5B Delta5B Washington2A Lafayette*2A Berrien*
3B Orange5B Denver5B Weld2A Lake*3A Bibb
3B Placer6B Dolores5B Yuma2A Lee*3A Bleckley*
5B Plumas5B DouglasCONNECTICUT2A Leon*2A Brantley*
3B Riverside6B Eagle2A Levy*2A Brooks*
3B Sacramento5B Elbert5A (all)2A Liberty*2A Bryan*
3C San Benito5B El PasoDELAWARE2A Madison*3A Bulloch*
3B San Bernardino5B Fremont2A Manatee*3A Burke
3B San Diego5B Garfield4A (all)2A Marion*3A Butts
3C San Francisco5B GilpinDISTRICT OF
COLUMBIA
2A Martin*3A Calhoun*
3B San Joaquin7 Grand1A Miami-Dade*2A Camden*
3C San Luis Obispo7 Gunnison4A (all)1A Monroe*3A Candler*
3C San Mateo7 HinsdaleFLORIDA2A Nassau*3A Carroll
3C Santa Barbara5B Huerfano2A Okaloosa*4A Catoosa
3C Santa Clara7 Jackson2A Alachua*2A Okeechobee*2A Charlton*
3C Santa Cruz5B Jefferson2A Baker*2A Orange*2A Chatham*
3B Shasta5B Kiowa2A Bay*2A Osceola*3A Chattahoochee*
5B Sierra5B Kit Carson2A Bradford*2A Palm Beach*4A Chattooga
5B Siskiyou7 Lake2A Brevard*2A Pasco*3A Cherokee
3B Solano5B La Plata1A Broward*2A Pinellas*3A Clarke
3C Sonoma5B Larimer2A Calhoun*2A Polk*3A Clay*
3B Stanislaus4B Las Animas2A Charlotte*2A Putnam*3A Clayton
3B Sutter5B Lincoln2A Citrus*2A Santa Rosa*2A Clinch*
3B Tehama5B Logan2A Clay*2A Sarasota*3A Cobb
4B Trinity5B Mesa2A Collier*2A Seminole*3A Coffee*
3B Tulare7 Mineral2A Columbia*2A St. Johns*2A Colquitt*
4B Tuolumne6B Moffat2A DeSoto*2A St. Lucie*3A Columbia
3C Ventura5B Montezuma2A Dixie*2A Sumter*2A Cook*
3B Yolo5B Montrose2A Duval*2A Suwannee*3A Coweta

(continued)

TABLE N1101.10 (R301.1)—continued
CLIMATE ZONES, MOISTURE REGIMES, AND WARM-HUMID
DESIGNATIONS BY STATE, COUNTY AND TERRITORY

3A Crawford2A Lanier*3A Taylor*5B Cassia4A Crawford
3A Crisp*3A Laurens*3A Telfair*6B Clark5A Cumberland
4A Dade3A Lee*3A Terrell*5B Clearwater5A DeKalb
4A Dawson2A Liberty*2A Thomas*6B Custer5A De Witt
2A Decatur*3A Lincoln3A Tift*5B Elmore5A Douglas
3A DeKalb2A Long*2A Toombs*6B Franklin5A DuPage
3A Dodge*2A Lowndes*4A Towns6B Fremont5A Edgar
3A Dooly*4A Lumpkin3A Treutlen*5B Gem4A Edwards
3A Dougherty*3A Macon*3A Troup5B Gooding4A Effingham
3A Douglas3A Madison3A Turner*5B Idaho4A Fayette
3A Early*3A Marion*3A Twiggs*6B Jefferson5A Ford
2A Echols*3A McDuffie4A Union5B Jerome4A Franklin
2A Effingham*2A McIntosh*3A Upson5B Kootenai5A Fulton
3A Elbert3A Meriwether4A Walker5B Latah4A Gallatin
3A Emanuel*2A Miller*3A Walton6B Lemhi5A Greene
2A Evans*2A Mitchell*2A Ware*5B Lewis5A Grundy
4A Fannin3A Monroe3A Warren5B Lincoln4A Hamilton
3A Fayette3A Montgomery*3A Washington6B Madison5A Hancock
4A Floyd3A Morgan2A Wayne*5B Minidoka4A Hardin
3A Forsyth4A Murray3A Webster*5B Nez Perce5A Henderson
4A Franklin3A Muscogee3A Wheeler*6B Oneida5A Henry
3A Fulton3A Newton4A White5B Owyhee5A Iroquois
4A Gilmer3A Oconee4A Whitfield5B Payette4A Jackson
3A Glascock3A Oglethorpe3A Wilcox*5B Power4A Jasper
2A Glynn*3A Paulding3A Wilkes5B Shoshone4A Jefferson
4A Gordon3A Peach*3A Wilkinson6B Teton5A Jersey
2A Grady*4A Pickens3A Worth*5B Twin Falls5A Jo Daviess
3A Greene2A Pierce*HAWAII6B Valley4A Johnson
3A Gwinnett3A Pike5B Washington5A Kane
4A Habersham3A Polk1A (all)*ILLINOIS5A Kankakee
4A Hall3A Pulaski*IDAHO5A Kendall
3A Hancock3A Putnam5A Adams5A Knox
3A Haralson3A Quitman*5B Ada4A Alexander5A Lake
3A Harris4A Rabun6B Adams4A Bond5A La Salle
3A Hart3A Randolph*6B Bannock5A Boone4A Lawrence
3A Heard3A Richmond6B Bear Lake5A Brown5A Lee
3A Henry3A Rockdale5B Benewah5A Bureau5A Livingston
3A Houston*3A Schley*6B Bingham5A Calhoun5A Logan
3A Irwin*3A Screven*6B Blaine5A Carroll5A Macon
3A Jackson2A Seminole*6B Boise5A Cass4A Macoupin
3A Jasper3A Spalding6B Bonner5A Champaign4A Madison
2A Jeff Davis*4A Stephens6B Bonneville4A Christian4A Marion
3A Jefferson3A Stewart*6B Boundary5A Clark5A Marshall
3A Jenkins*3A Sumter*6B Butte4A Clay5A Mason
3A Johnson*3A Talbot6B Camas4A Clinton4A Massac
3A Jones3A Taliaferro5B Canyon5A Coles5A McDonough
3A Lamar2A Tattnall*6B Caribou5A Cook5A McHenry

(continued)

TABLE N1101.10 (R301.1)—continued
CLIMATE ZONES, MOISTURE REGIMES, AND WARM-HUMID
DESIGNATIONS BY STATE, COUNTY AND TERRITORY

5A McLean5A Boone5A Miami5A Appanoose5A Jasper
5A Menard4A Brown4A Monroe5A Audubon5A Jefferson
5A Mercer5A Carroll5A Montgomery5A Benton5A Johnson
4A Monroe5A Cass5A Morgan6A Black Hawk5A Jones
4A Montgomery4A Clark5A Newton5A Boone5A Keokuk
5A Morgan5A Clay5A Noble6A Bremer6A Kossuth
5A Moultrie5A Clinton4A Ohio6A Buchanan5A Lee
5A Ogle4A Crawford4A Orange6A Buena Vista5A Linn
5A Peoria4A Daviess5A Owen6A Butler5A Louisa
4A Perry4A Dearborn5A Parke6A Calhoun5A Lucas
5A Piatt5A Decatur4A Perry5A Carroll6A Lyon
5A Pike5A De Kalb4A Pike5A Cass5A Madison
4A Pope5A Delaware5A Porter5A Cedar5A Mahaska
4A Pulaski4A Dubois4A Posey6A Cerro Gordo5A Marion
5A Putnam5A Elkhart5A Pulaski6A Cherokee5A Marshall
4A Randolph5A Fayette5A Putnam6A Chickasaw5A Mills
4A Richland4A Floyd5A Randolph5A Clarke6A Mitchell
5A Rock Island5A Fountain4A Ripley6A Clay5A Monona
4A Saline5A Franklin5A Rush6A Clayton5A Monroe
5A Sangamon5A Fulton4A Scott5A Clinton5A Montgomery
5A Schuyler4A Gibson5A Shelby5A Crawford5A Muscatine
5A Scott5A Grant4A Spencer5A Dallas6A O’Brien
4A Shelby4A Greene5A Starke5A Davis6A Osceola
5A Stark5A Hamilton5A Steuben5A Decatur5A Page
4A St. Clair5A Hancock5A St. Joseph6A Delaware6A Palo Alto
5A Stephenson4A Harrison4A Sullivan5A Des Moines6A Plymouth
5A Tazewell5A Hendricks4A Switzerland6A Dickinson6A Pocahontas
4A Union5A Henry5A Tippecanoe5A Dubuque5A Polk
5A Vermilion5A Howard5A Tipton6A Emmet5A Pottawattamie
4A Wabash5A Huntington5A Union6A Fayette5A Poweshiek
5A Warren4A Jackson4A Vanderburgh6A Floyd5A Ringgold
4A Washington5A Jasper5A Vermillion6A Franklin6A Sac
4A Wayne5A Jay5A Vigo5A Fremont5A Scott
4A White4A Jefferson5A Wabash5A Greene5A Shelby
5A Whiteside4A Jennings5A Warren6A Grundy6A Sioux
5A Will5A Johnson4A Warrick5A Guthrie5A Story
4A Williamson4A Knox4A Washington6A Hamilton5A Tama
5A Winnebago5A Kosciusko5A Wayne6A Hancock5A Taylor
5A Woodford5A Lagrange5A Wells6A Hardin5A Union
INDIANA5A Lake5A White5A Harrison5A Van Buren
5A La Porte5A Whitley5A Henry5A Wapello
5A Adams4A LawrenceIOWA6A Howard5A Warren
5A Allen5A Madison6A Humboldt5A Washington
5A Bartholomew5A Marion5A Adair6A Ida5A Wayne
5A Benton5A Marshall5A Adams5A Iowa6A Webster
5A Blackford4A Martin6A Allamakee5A Jackson6A Winnebago

(continued)

TABLE N1101.10 (R301.1)—continued
CLIMATE ZONES, MOISTURE REGIMES, AND WARM-HUMID
DESIGNATIONS BY STATE, COUNTY AND TERRITORY

6A Winneshiek4A Hodgeman4A Seward2A Iberville*6A Cumberland
5A Woodbury4A Jackson4A Shawnee3A Jackson*6A Franklin
6A Worth4A Jefferson5A Sheridan2A Jefferson*6A Hancock
6A Wright5A Jewell5A Sherman2A Jefferson Davis6A Kennebec
KANSAS4A Johnson5A Smith2A Lafayette*6A Knox
4A Kearny4A Stafford2A Lafourche*6A Lincoln
4A Allen4A Kingman4A Stanton3A La Salle*6A Oxford
4A Anderson4A Kiowa4A Stevens3A Lincoln*6A Penobscot
4A Atchison4A Labette4A Sumner2A Livingston*6A Piscataquis
4A Barber5A Lane5A Thomas3A Madison*6A Sagadahoc
4A Barton4A Leavenworth5A Trego3A Morehouse6A Somerset
4A Bourbon4A Lincoln4A Wabaunsee3A Natchitoches*6A Waldo
4A Brown4A Linn5A Wallace2A Orleans*6A Washington
4A Butler5A Logan4A Washington3A Ouachita*6A York
4A Chase4A Lyon5A Wichita2A Plaquemines*MARYLAND
4A Chautauqua4A Marion4A Wilson2A Pointe Coupee*
4A Cherokee4A Marshall4A Woodson2A Rapides*4A Allegany
5A Cheyenne4A McPherson4A Wyandotte3A Red River*4A Anne Arundel
4A Clark4A MeadeKENTUCKY3A Richland*4A Baltimore
4A Clay4A Miami3A Sabine*4A Baltimore (city)
5A Cloud5A Mitchell4A (all)2A St. Bernard*4A Calvert
4A Coffey4A MontgomeryLOUISIANA2A St. Charles*4A Caroline
4A Comanche4A Morris2A St. Helena*4A Carroll
4A Cowley4A Morton2A Acadia*2A St. James*4A Cecil
4A Crawford4A Nemaha2A Allen*2A St. John the4A Charles
5A Decatur4A Neosho2A Ascension*Baptist*4A Dorchester
4A Dickinson5A Ness2A Assumption*2A St. Landry*4A Frederick
4A Doniphan5A Norton2A Avoyelles*2A St. Martin*5A Garrett
4A Douglas4A Osage2A Beauregard*2A St. Mary*4A Harford
4A Edwards5A Osborne3A Bienville*2A St. Tammany*4A Howard
4A Elk4A Ottawa3A Bossier*2A Tangipahoa*4A Kent
5A Ellis4A Pawnee3A Caddo*3A Tensas*4A Montgomery
4A Ellsworth5A Phillips2A Calcasieu*2A Terrebonne*4A Prince George's
4A Finney4A Pottawatomie3A Caldwell*3A Union*4A Queen Anne's
4A Ford4A Pratt2A Cameron*2A Vermilion*4A Somerset
4A Franklin5A Rawlins3A Catahoula*3A Vernon*4A St. Mary's
4A Geary4A Reno3A Claiborne*2A Washington*4A Talbot
5A Gove5A Republic3A Concordia*3A Webster*4A Washington
5A Graham4A Rice3A De Soto*2A West Baton4A Wicomico
4A Grant4A Riley2A East BatonRouge*4A Worcester
4A Gray5A RooksRouge*3A West CarrollMASSACHSETTS
5A Greeley4A Rush3A East Carroll2A West Feliciana*
4A Greenwood4A Russell2A East Feliciana*3A Winn*5A (all)
5A Hamilton4A Saline2A Evangeline*MAINEMICHIGAN
4A Harper5A Scott3A Franklin*
4A Harvey4A Sedgwick3A Grant*6A Androscoggin6A Alcona
4A Haskell2A Iberia*7 Aroostook6A Alger

(continued)

TABLE N1101.10 (R301.1)—continued
CLIMATE ZONES, MOISTURE REGIMES, AND WARM-HUMID
DESIGNATIONS BY STATE, COUNTY AND TERRITORY

5A Allegan7 Mackinac6A Carver7 Otter Tail3A Clay
6A Alpena5A Macomb7 Cass7 Pennington3A Coahoma
6A Antrim6A Manistee6A Chippewa7 Pine3A Copiah*
6A Arenac6A Marquette6A Chisago6A Pipestone3A Covington*
7 Baraga6A Mason7 Clay7 Polk3A DeSoto
5A Barry6A Mecosta7 Clearwater6A Pope3A Forrest*
5A Bay6A Menominee7 Cook6A Ramsey3A Franklin*
6A Benzie5A Midland6A Cottonwood7 Red Lake3A George*
5A Berrien6A Missaukee7 Crow Wing6A Redwood3A Greene*
5A Branch5A Monroe6A Dakota6A Renville3A Grenada
5A Calhoun5A Montcalm6A Dodge6A Rice2A Hancock*
5A Cass6A Montmorency6A Douglas6A Rock2A Harrison*
6A Charlevoix5A Muskegon6A Faribault7 Roseau3A Hinds*
6A Cheboygan6A Newaygo6A Fillmore6A Scott3A Holmes
7 Chippewa5A Oakland6A Freeborn6A Sherburne3A Humphreys
6A Clare6A Oceana6A Goodhue6A Sibley3A Issaquena
5A Clinton6A Ogemaw7 Grant6A Stearns3A Itawamba
6A Crawford7 Ontonagon6A Hennepin6A Steele2A Jackson*
6A Delta6A Osceola6A Houston6A Stevens3A Jasper
6A Dickinson6A Oscoda7 Hubbard7 St. Louis3A Jefferson*
5A Eaton6A Otsego6A Isanti6A Swift3A Jefferson Davis*
6A Emmet5A Ottawa7 Itasca6A Todd3A Jones*
5A Genesee6A Presque Isle6A Jackson6A Traverse3A Kemper
6A Gladwin6A Roscommon7 Kanabec6A Wabasha3A Lafayette
7 Gogebic5A Saginaw6A Kandiyohi7 Wadena3A Lamar*
6A Grand Traverse6A Sanilac7 Kittson6A Waseca3A Lauderdale
5A Gratiot7 Schoolcraft7 Koochiching6A Washington3A Lawrence*
5A Hillsdale5A Shiawassee6A Lac qui Parle6A Watonwan3A Leake
7 Houghton5A St. Clair7 Lake7 Wilkin3A Lee
6A Huron5A St. Joseph7 Lake of the Woods6A Winona3A Leflore
5A Ingham5A Tuscola6A Le Sueur6A Wright3A Lincoln*
5A Ionia5A Van Buren6A Lincoln6A Yellow Medicine3A Lowndes
6A Iosco5A Washtenaw6A LyonMISSISSIPPI3A Madison
7 Iron5A Wayne7 Mahnomen3A Marion*
6A Isabella6A Wexford7 Marshall3A Adams*3A Marshall
5A JacksonMINNESOTA6A Martin3A Alcorn3A Monroe
5A Kalamazoo6A McLeod3A Amite*3A Montgomery
6A Kalkaska7 Aitkin6A Meeker3A Attala3A Neshoba
5A Kent6A Anoka7 Mille Lacs3A Benton3A Newton
7 Keweenaw7 Becker6A Morrison3A Bolivar3A Noxubee
6A Lake7 Beltrami6A Mower3A Calhoun3A Oktibbeha
5A Lapeer6A Benton6A Murray3A Carroll3A Panola
6A Leelanau6A Big Stone6A Nicollet3A Chickasaw2A Pearl River*
5A Lenawee6A Blue Earth6A Nobles3A Choctaw3A Perry*
5A Livingston6A Brown7 Norman3A Claiborne*3A Pike*
7 Luce7 Carlton6A Olmsted3A Clarke

(continued)

TABLE N1101.10 (R301.1)—continued
CLIMATE ZONES, MOISTURE REGIMES, AND WARM-HUMID
DESIGNATIONS BY STATE, COUNTY AND TERRITORY

3A Pontotoc5A Chariton4A Mississippi4A Webster4A Cumberland
3A Prentiss4A Christian4A Moniteau5A Worth4A Essex
3A Quitman5A Clark4A Monroe4A Wright4A Gloucester
3A Rankin*4A Clay4A MontgomeryMONTANA4A Hudson
3A Scott5A Clinton4A Morgan5A Hunterdon
3A Sharkey4A Cole4A New Madrid6B (all)5A Mercer
3A Simpson*4A Cooper4A NewtonNEBRASKA4A Middlesex
3A Smith*4A Crawford5A Nodaway4A Monmouth
2A Stone*4A Dade4A Oregon5A (all)5A Morris
3A Sunflower4A Dallas4A OsageNEVADA4A Ocean
3A Tallahatchie5A Daviess4A Ozark5A Passaic
3A Tate5A DeKalb4A Pemiscot5B Carson City (city)4A Salem
3A Tippah4A Dent4A Perry5B Churchill5A Somerset
3A Tishomingo4A Douglas4A Pettis3B Clark5A Sussex
3A Tunica4A Dunklin4A Phelps5B Douglas4A Union
3A Union4A Franklin5A Pike5B Elko5A Warren
3A Walthall*4A Gasconade4A Platte5B EsmeraldaNEW MEXICO
3A Warren*5A Gentry4A Polk5B Eureka
3A Washington4A Greene4A Pulaski5B Humboldt4B Bernalillo
3A Wayne*5A Grundy5A Putnam5B Lander5B Catron
3A Webster5A Harrison5A Ralls5B Lincoln3B Chaves
3A Wilkinson*4A Henry4A Randolph5B Lyon4B Cibola
3A Winston4A Hickory4A Ray5B Mineral5B Colfax
3A Yalobusha5A Holt4A Reynolds5B Nye4B Curry
3A Yazoo4A Howard4A Ripley5B Pershing4B DeBaca
MISSOURI4A Howell4A Saline5B Storey3B Dona Ana
4A Iron5A Schuyler5B Washoe3B Eddy
5A Adair4A Jackson5A Scotland5B White Pine4B Grant
5A Andrew4A Jasper4A ScottNEW
HAMPSHIRE
4B Guadalupe
5A Atchison4A Jefferson4A Shannon5B Harding
4A Audrain4A Johnson5A Shelby6A Belknap3B Hidalgo
4A Barry5A Knox4A St. Charles6A Carroll3B Lea
4A Barton4A Laclede4A St. Clair5A Cheshire4B Lincoln
4A Bates4A Lafayette4A Ste. Genevieve6A Coos5B Los Alamos
4A Benton4A Lawrence4A St. Francois6A Grafton3B Luna
4A Bollinger5A Lewis4A St. Louis5A Hillsborough5B McKinley
4A Boone4A Lincoln4A St. Louis (city)6A Merrimack5B Mora
5A Buchanan5A Linn4A Stoddard5A Rockingham3B Otero
4A Butler5A Livingston4A Stone5A Strafford4B Quay
5A Caldwell5A Macon5A Sullivan6A Sullivan5B Rio Arriba
4A Callaway4A Madison4A TaneyNEW JERSEY4B Roosevelt
4A Camden4A Maries4A Texas5B Sandoval
4A Cape Girardeau5A Marion4A Vernon4A Atlantic5B San Juan
4A Carroll4A McDonald4A Warren5A Bergen5B San Miguel
4A Carter5A Mercer4A Washington4A Burlington5B Santa Fe
4A Cass4A Miller4A Wayne4A Camden4B Sierra
4A Cedar4A Cape May4B Socorro

(continued)

TABLE N1101.10 (R301.1)—continued
CLIMATE ZONES, MOISTURE REGIMES, AND WARM-HUMID
DESIGNATIONS BY STATE, COUNTY AND TERRITORY

5B Taos4A Queens4A Clay4A Orange7 Divide
5B Torrance5A Rensselaer4A Cleveland3A Pamlico6A Dunn
4B Union4A Richmond3A Columbus*3A Pasquotank7 Eddy
4B Valencia5A Rockland3A Craven3A Pender*6A Emmons
NEW YORK5A Saratoga3A Cumberland3A Perquimans7 Foster
5A Schenectady3A Currituck4A Person6A Golden Valley
5A Albany6A Schoharie3A Dare3A Pitt7 Grand Forks
6A Allegany6A Schuyler3A Davidson4A Polk6A Grant
4A Bronx5A Seneca4A Davie3A Randolph7 Griggs
6A Broome6A Steuben3A Duplin3A Richmond6A Hettinger
6A Cattaraugus6A St. Lawrence4A Durham3A Robeson7 Kidder
5A Cayuga4A Suffolk3A Edgecombe4A Rockingham6A LaMoure
5A Chautauqua6A Sullivan4A Forsyth3A Rowan6A Logan
5A Chemung5A Tioga4A Franklin4A Rutherford7 McHenry
6A Chenango6A Tompkins3A Gaston3A Sampson6A McIntosh
6A Clinton6A Ulster4A Gates3A Scotland6A McKenzie
5A Columbia6A Warren4A Graham3A Stanly7 McLean
5A Cortland5A Washington4A Granville4A Stokes6A Mercer
6A Delaware5A Wayne3A Greene4A Surry6A Morton
5A Dutchess4A Westchester4A Guilford4A Swain7 Mountrail
5A Erie6A Wyoming4A Halifax4A Transylvania7 Nelson
6A Essex5A Yates4A Harnett3A Tyrrell6A Oliver
6A FranklinNORTH
CAROLINA
4A Haywood3A Union7 Pembina
6A Fulton4A Henderson4A Vance7 Pierce
5A Genesee4A Alamance4A Hertford4A Wake7 Ramsey
5A Greene4A Alexander3A Hoke4A Warren6A Ransom
6A Hamilton5A Alleghany3A Hyde3A Washington7 Renville
6A Herkimer3A Anson4A Iredell5A Watauga6A Richland
6A Jefferson5A Ashe4A Jackson3A Wayne7 Rolette
4A Kings5A Avery3A Johnston4A Wilkes6A Sargent
6A Lewis3A Beaufort3A Jones3A Wilson7 Sheridan
5A Livingston4A Bertie4A Lee4A Yadkin6A Sioux
6A Madison3A Bladen3A Lenoir5A Yancey6A Slope
5A Monroe3A Brunswick*4A LincolnNORTH DAKOTA6A Stark
6A Montgomery4A Buncombe4A Macon7 Steele
4A Nassau4A Burke4A Madison6A Adams7 Stutsman
4A New York3A Cabarrus3A Martin7 Barnes7 Towner
5A Niagara4A Caldwell4A McDowell7 Benson7 Traill
6A Oneida3A Camden3A Mecklenburg6A Billings7 Walsh
5A Onondaga3A Carteret*5A Mitchell7 Bottineau7 Ward
5A Ontario4A Caswell3A Montgomery6A Bowman7 Wells
5A Orange4A Catawba3A Moore7 Burke7 Williams
5A Orleans4A Chatham4A Nash6A BurleighOHIO
5A Oswego4A Cherokee3A New Hanover*7 Cass
6A Otsego3A Chowan4A Northampton7 Cavalier4A Adams
5A Putnam3A Onslow*6A Dickey5A Allen

(continued)

TABLE N1101.10 (R301.1)—continued
CLIMATE ZONES, MOISTURE REGIMES, AND WARM-HUMID
DESIGNATIONS BY STATE, COUNTY AND TERRITORY

5A Ashland5A Mahoning3A Bryan3A Okfuskee4C Linn
5A Ashtabula5A Marion3A Caddo3A Oklahoma5B Malheur
5A Athens5A Medina3A Canadian3A Okmulgee4C Marion
5A Auglaize5A Meigs3A Carter3A Osage5B Morrow
5A Belmont5A Mercer3A Cherokee3A Ottawa4C Multnomah
4A Brown5A Miami3A Choctaw3A Pawnee4C Polk
5A Butler5A Monroe4B Cimarron3A Payne5B Sherman
5A Carroll5A Montgomery3A Cleveland3A Pittsburg4C Tillamook
5A Champaign5A Morgan3A Coal3A Pontotoc5B Umatilla
5A Clark5A Morrow3A Comanche3A Pottawatomie5B Union
4A Clermont5A Muskingum3A Cotton3A Pushmataha5B Wallowa
5A Clinton5A Noble3A Craig3A Roger Mills5B Wasco
5A Columbiana5A Ottawa3A Creek3A Rogers4C Washington
5A Coshocton5A Paulding3A Custer3A Seminole5B Wheeler
5A Crawford5A Perry3A Delaware3A Sequoyah4C Yamhill
5A Cuyahoga5A Pickaway3A Dewey3A StephensPENNSYLVANIA
5A Darke4A Pike3A Ellis4B Texas
5A Defiance5A Portage3A Garfield3A Tillman5A Adams
5A Delaware5A Preble3A Garvin3A Tulsa5A Allegheny
5A Erie5A Putnam3A Grady3A Wagoner5A Armstrong
5A Fairfield5A Richland3A Grant3A Washington5A Beaver
5A Fayette5A Ross3A Greer3A Washita5A Bedford
5A Franklin5A Sandusky3A Harmon3A Woods5A Berks
5A Fulton4A Scioto3A Harper3A Woodward5A Blair
4A Gallia5A Seneca3A HaskellOREGON5A Bradford
5A Geauga5A Shelby3A Hughes4A Bucks
5A Greene5A Stark3A Jackson5B Baker5A Butler
5A Guernsey5A Summit3A Jefferson4C Benton5A Cambria
4A Hamilton5A Trumbull3A Johnston4C Clackamas6A Cameron
5A Hancock5A Tuscarawas3A Kay4C Clatsop5A Carbon
5A Hardin5A Union3A Kingfisher4C Columbia5A Centre
5A Harrison5A Van Wert3A Kiowa4C Coos4A Chester
5A Henry5A Vinton3A Latimer5B Crook5A Clarion
5A Highland5A Warren3A Le Flore4C Curry6A Clearfield
5A Hocking4A Washington3A Lincoln5B Deschutes5A Clinton
5A Holmes5A Wayne3A Logan4C Douglas5A Columbia
5A Huron5A Williams3A Love5B Gilliam5A Crawford
5A Jackson5A Wood3A Major5B Grant5A Cumberland
5A Jefferson5A Wyandot3A Marshall5B Harney5A Dauphin
5A KnoxOKLAHOMA3A Mayes5B Hood River4A Delaware
5A Lake3A McClain4C Jackson6A Elk
4A Lawrence3A Adair3A McCurtain5B Jefferson5A Erie
5A Licking3A Alfalfa3A McIntosh4C Josephine5A Fayette
5A Logan3A Atoka3A Murray5B Klamath5A Forest
5A Lorain4B Beaver3A Muskogee5B Lake5A Franklin
5A Lucas3A Beckham3A Noble4C Lane5A Fulton
5A Madison3A Blaine3A Nowata4C Lincoln5A Greene

(continued)

TABLE N1101.10 (R301.1)—continued
CLIMATE ZONES, MOISTURE REGIMES, AND WARM-HUMID
DESIGNATIONS BY STATE, COUNTY AND TERRITORY

5A Huntingdon3A Bamberg*5A Bennett6A Minnehaha4A Gibson
5A Indiana3A Barnwell*5A Bon Homme6A Moody4A Giles
5A Jefferson3A Beaufort*6A Brookings6A Pennington4A Grainger
5A Juniata3A Berkeley*6A Brown6A Perkins4A Greene
5A Lackawanna3A Calhoun6A Brule6A Potter4A Grundy
5A Lancaster3A Charleston*6A Buffalo6A Roberts4A Hamblen
5A Lawrence3A Cherokee6A Butte6A Sanborn4A Hamilton
5A Lebanon3A Chester6A Campbell6A Shannon4A Hancock
5A Lehigh3A Chesterfield5A Charles Mix6A Spink3A Hardeman
5A Luzerne3A Clarendon6A Clark6A Stanley3A Hardin
5A Lycoming3A Colleton*5A Clay6A Sully4A Hawkins
6A McKean3A Darlington6A Codington5A Todd3A Haywood
5A Mercer3A Dillon6A Corson5A Tripp3A Henderson
5A Mifflin3A Dorchester*6A Custer6A Turner4A Henry
5A Monroe3A Edgefield6A Davison5A Union4A Hickman
4A Montgomery3A Fairfield6A Day6A Walworth4A Houston
5A Montour3A Florence6A Deuel5A Yankton4A Humphreys
5A Northampton3A Georgetown*6A Dewey6A Ziebach4A Jackson
5A Northumberland3A Greenville5A DouglasTENNESSEE4A Jefferson
5A Perry3A Greenwood6A Edmunds4A Johnson
4A Philadelphia3A Hampton*6A Fall River4A Anderson4A Knox
5A Pike3A Horry*6A Faulk4A Bedford3A Lake
6A Potter3A Jasper*6A Grant4A Benton3A Lauderdale
5A Schuylkill3A Kershaw5A Gregory4A Bledsoe4A Lawrence
5A Snyder3A Lancaster6A Haakon4A Blount4A Lewis
5A Somerset3A Laurens6A Hamlin4A Bradley4A Lincoln
5A Sullivan3A Lee6A Hand4A Campbell4A Loudon
6A Susquehanna3A Lexington6A Hanson4A Cannon4A Macon
6A Tioga3A Marion6A Harding4A Carroll3A Madison
5A Union3A Marlboro6A Hughes4A Carter4A Marion
5A Venango3A McCormick5A Hutchinson4A Cheatham4A Marshall
5A Warren3A Newberry6A Hyde3A Chester4A Maury
5A Washington3A Oconee5A Jackson4A Claiborne4A McMinn
6A Wayne3A Orangeburg6A Jerauld4A Clay3A McNairy
5A Westmoreland3A Pickens6A Jones4A Cocke4A Meigs
5A Wyoming3A Richland6A Kingsbury4A Coffee4A Monroe
4A York3A Saluda6A Lake3A Crockett4A Montgomery
RHODE ISLAND3A Spartanburg6A Lawrence4A Cumberland4A Moore
3A Sumter6A Lincoln4A Davidson4A Morgan
5A (all)3A Union6A Lyman4A Decatur4A Obion
SOUTH
CAROLINA
3A Williamsburg6A Marshall4A DeKalb4A Overton
3A York6A McCook4A Dickson4A Perry
3A AbbevilleSOUTH DAKOTA6A McPherson3A Dyer4A Pickett
3A Aiken6A Meade3A Fayette4A Polk
3A Allendale*6A Aurora5A Mellette4A Fentress4A Putnam
3A Anderson6A Beadle6A Miner4A Franklin4A Rhea

(continued)

TABLE N1101.10 (R301.1)—continued
CLIMATE ZONES, MOISTURE REGIMES, AND WARM-HUMID
DESIGNATIONS BY STATE, COUNTY AND TERRITORY

4A Roane3B Brewster3B Ector3B Howard3B McCulloch
4A Robertson4B Briscoe2B Edwards*3B Hudspeth2A McLennan*
4A Rutherford2A Brooks*3A Ellis*3A Hunt*2A McMullen*
4A Scott3A Brown*3B El Paso4B Hutchinson2B Medina*
4A Sequatchie2A Burleson*3A Erath*3B Irion3B Menard
4A Sevier3A Burnet*2A Falls*3A Jack3B Midland
3A Shelby2A Caldwell*3A Fannin2A Jackson*2A Milam*
4A Smith2A Calhoun*2A Fayette*2A Jasper*3A Mills*
4A Stewart3B Callahan3B Fisher3B Jeff Davis3B Mitchell
4A Sullivan2A Cameron*4B Floyd2A Jefferson*3A Montague
4A Sumner3A Camp*3B Foard2A Jim Hogg*2A Montgomery*
3A Tipton4B Carson2A Fort Bend*2A Jim Wells*4B Moore
4A Trousdale3A Cass*3A Franklin*3A Johnson*3A Morris*
4A Unicoi4B Castro2A Freestone*3B Jones3B Motley
4A Union2A Chambers*2B Frio*2A Karnes*3A Nacogdoches*
4A Van Buren2A Cherokee*3B Gaines3A Kaufman*3A Navarro*
4A Warren3B Childress2A Galveston*3A Kendall*2A Newton*
4A Washington3A Clay3B Garza2A Kenedy*3B Nolan
4A Wayne4B Cochran3A Gillespie*3B Kent2A Nueces*
4A Weakley3B Coke3B Glasscock3B Kerr4B Ochiltree
4A White3B Coleman2A Goliad*3B Kimble4B Oldham
4A Williamson3A Collin*2A Gonzales*3B King2A Orange*
4A Wilson3B Collingsworth4B Gray2B Kinney*3A Palo Pinto*
TEXAS2A Colorado*3A Grayson2A Kleberg*3A Panola*
2A Comal*3A Gregg*3B Knox3A Parker*
2A Anderson*3A Comanche*2A Grimes*3A Lamar*4B Parmer
3B Andrews3B Concho2A Guadalupe*4B Lamb3B Pecos
2A Angelina*3A Cooke4B Hale3A Lampasas*2A Polk*
2A Aransas*2A Coryell*3B Hall2B La Salle*4B Potter
3A Archer3B Cottle3A Hamilton*2A Lavaca*3B Presidio
4B Armstrong3B Crane4B Hansford2A Lee*3A Rains*
2A Atascosa*3B Crockett3B Hardeman2A Leon*4B Randall
2A Austin*3B Crosby2A Hardin*2A Liberty*3B Reagan
4B Bailey3B Culberson2A Harris*2A Limestone*2B Real*
2B Bandera*4B Dallam3A Harrison*4B Lipscomb3A Red River*
2A Bastrop*3A Dallas*4B Hartley2A Live Oak*3B Reeves
3B Baylor3B Dawson3B Haskell3A Llano*2A Refugio*
2A Bee*4B Deaf Smith2A Hays*3B Loving4B Roberts
2A Bell*3A Delta3B Hemphill3B Lubbock2A Robertson*
2A Bexar*3A Denton*3A Henderson*3B Lynn3A Rockwall*
3A Blanco*2A DeWitt*2A Hidalgo*2A Madison*3B Runnels
3B Borden3B Dickens2A Hill*3A Marion*3A Rusk*
2A Bosque*2B Dimmit*4B Hockley3B Martin3A Sabine*
3A Bowie*4B Donley3A Hood*3B Mason3A San Augustine*
2A Brazoria*2A Duval*3A Hopkins*2A Matagorda*2A San Jacinto*
2A Brazos*3A Eastland2A Houston*2B Maverick*2A San Patricio*

(continued)

TABLE N1101.10 (R301.1)—continued
CLIMATE ZONES, MOISTURE REGIMES, AND WARM-HUMID
DESIGNATIONS BY STATE, COUNTY AND TERRITORY

3A San Saba*3A Young4C Clark4A GilmerWISCONSIN
3B Schleicher2B Zapata*5B Columbia5A Grant6A Adams
3B Scurry2B Zavala*4C Cowlitz5A Greenbrier7 Ashland
3B ShackelfordUTAH5B Douglas5A Hampshire6A Barron
3A Shelby*6B Ferry5A Hancock7 Bayfield
4B Sherman5B Beaver5B Franklin5A Hardy6A Brown
3A Smith*6B Box Elder5B Garfield5A Harrison6A Buffalo
3A Somervell*6B Cache5B Grant4A Jackson7 Burnett
2A Starr*6B Carbon4C Grays Harbor4A Jefferson6A Calumet
3A Stephens6B Daggett4C Island4A Kanawha6A Chippewa
3B Sterling5B Davis4C Jefferson5A Lewis6A Clark
3B Stonewall6B Duchesne4C King4A Lincoln6A Columbia
3B Sutton5B Emery4C Kitsap4A Logan6A Crawford
4B Swisher5B Garfield5B Kittitas5A Marion6A Dane
3A Tarrant*5B Grand5B Klickitat5A Marshall6A Dodge
3B Taylor5B Iron4C Lewis4A Mason6A Door
3B Terrell5B Juab5B Lincoln4A McDowell7 Douglas
3B Terry5B Kane4C Mason4A Mercer6A Dunn
3B Throckmorton5B Millard6B Okanogan5A Mineral6A Eau Claire
3A Titus*6B Morgan4C Pacific4A Mingo7 Florence
3B Tom Green5B Piute6B Pend Oreille5A Monongalia6A Fond du Lac
2A Travis*6B Rich4C Pierce4A Monroe7 Forest
2A Trinity*5B Salt Lake4C San Juan4A Morgan6A Grant
2A Tyler*5B San Juan4C Skagit5A Nicholas6A Green
3A Upshur*5B Sanpete5B Skamania5A Ohio6A Green Lake
3B Upton5B Sevier4C Snohomish5A Pendleton6A Iowa
2B Uvalde*6B Summit5B Spokane4A Pleasants7 Iron
2B Val Verde*5B Tooele6B Stevens5A Pocahontas6A Jackson
3A Van Zandt*6B Uintah4C Thurston5A Preston6A Jefferson
2A Victoria*5B Utah4C Wahkiakum4A Putnam6A Juneau
2A Walker*6B Wasatch5B Walla Walla5A Raleigh6A Kenosha
2A Waller*3B Washington4C Whatcom5A Randolph6A Kewaunee
3B Ward5B Wayne5B Whitman4A Ritchie6A La Crosse
2A Washington*5B Weber5B Yakima4A Roane6A Lafayette
2B Webb*VERMONTWEST VIRGINIA5A Summers7 Langlade
2A Wharton*5A Taylor7 Lincoln
3B Wheeler6A (all)5A Barbour5A Tucker6A Manitowoc
3A WichitaVIRGINIA4A Berkeley4A Tyler6A Marathon
3B Wilbarger4A Boone5A Upshur6A Marinette
2A Willacy*4A (all)4A Braxton4A Wayne6A Marquette
2A Williamson*WASHINGTON5A Brooke5A Webster6A Menominee
2A Wilson*4A Cabell5A Wetzel6A Milwaukee
3B Winkler5B Adams4A Calhoun4A Wirt6A Monroe
3A Wise5B Asotin4A Clay4A Wood6A Oconto
3A Wood*5B Benton5A Doddridge4A Wyoming7 Oneida
4B Yoakum5B Chelan5A Fayette6A Outagamie
4C Clallam

(continued)

TABLE N1101.10 (R301.1)—continued
CLIMATE ZONES, MOISTURE REGIMES, AND WARM-HUMID
DESIGNATIONS BY STATE, COUNTY AND TERRITORY

6A Ozaukee7 Taylor6B Big Horn6B SheridanNORTHERN
MARIANA
ISLANDS
6A Pepin6A Trempealeau6B Campbell7 Sublette
6A Pierce6A Vernon6B Carbon6B Sweetwater
6A Polk7 Vilas6B Converse7 Teton1A (all)*
6A Portage6A Walworth6B Crook6B UintaPUERTO RICO
7 Price7 Washburn6B Fremont6B Washakie
6A Racine6A Washington5B Goshen6B Weston1A (all)*
6A Richland6A Waukesha6B Hot SpringsUS TERRITORIESVIRGIN ISLANDS
6A Rock6A Waupaca6B Johnson
6A Rusk6A Waushara6B LaramieAMERICAN
SAMOA
1A (all)*
6A Sauk6A Winnebago7 Lincoln
7 Sawyer6A Wood6B Natrona1A (all)*
6A ShawanoWYOMING6B NiobraraGUAM
6A Sheboygan6B Park
6A St. Croix6B Albany5B Platte1A (all)*
Warm humid counties are identified in Table N1101.10 by an asterisk.
The climate zone for any location outside the United States shall be determined by applying Table N1101.10.2(1) and then Table N1101.10.2(2).

TABLE N1101.10.2(1) [R302.3(1)]
INTERNATIONAL CLIMATE ZONE DEFINITIONS

MAJOR CLIMATE TYPE DEFINITIONS
Marine (C) Definition—Locations meeting all four criteria:
1. Mean temperature of coldest month between -3°C (27°F) and 18°C (65°F).
2. Warmest month mean < 22°C (72°F).
3. At least four months with mean temperatures over 10°C (50°F).
4. Dry season in summer. The month with the heaviest precipitation in the cold season has at least three times as much precipitation as the month with the least precipitation in the rest of the year. The cold season is October through March in the Northern Hemisphere and
April through September in the Southern Hemisphere.
Dry (B) Definition—Locations meeting the following criteria:
Not marine and Pin < 0.44 × (TF - 19.5) [Pcm < 2.0 × (TC + 7) in SI units]
where:
Pin = Annual precipitation in inches (cm)
T = Annual mean temperature in °F (°C)
Moist (A) Definition—Locations that are not marine and not dry.
Warm-humid Definition—Moist (A) locations where either of the following wet-bulb temperature conditions shall occur during the warmest
six consecutive months of the year:
1. 67°F (19.4°C) or higher for 3,000 or more hours; or
2. 73°F (22.8°C) or higher for 1,500 or more hours.
For SI: °C = [(°F)-32]/1.8, 1 inch = 2.54 cm.

TABLE N1101.10.2(2) [R301.3(2)]
INTERNATIONAL CLIMATE ZONE DEFINITIONS

ZONE
NUMBER
THERMAL CRITERIA
IP Units SI Units
1 9000 < CDD50°F5000 < CDD10°C
2 6300 < CDD50°F ≤ 90003500 < CDD10°C ≤ 5000
3A and 3B 4500 < CDD50°F ≤ 6300 AND HDD65°F ≤ 54002500 < CDD10°C ≤ 3500 AND HDD18°C ≤ 3000
4A and 4B CDD50°F ≤ 4500 AND HDD65°F ≤ 5400CDD10°C ≤ 2500 AND HDD18°C ≤ 3000
3C HDD65°F ≤ 3600HDD18°C ≤ 2000
4C 3600 < HDD65°F ≤ 54002000 < HDD18°C ≤ 3000
5 5400 < HDD65°F ≤ 72003000 < HDD18°C ≤ 4000
6 7200 < HDD65°F ≤ 90004000 < HDD18°C ≤ 5000
7 9000 < HDD65°F ≤ 126005000 < HDD18°C ≤ 7000
8 12600 < HDD65°F7000 < HDD18°C
For SI: °C = [(°F)-32]/1.8.
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 sprayed polyurethane foam (SPF) insulation, the installed thickness of the areas covered and R-value of installed thickness 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 a minimum of 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.
U-factors of fenestration products (windows, doors and skylights) shall be determined in accordance with NFRC 100 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 Table N1101.12.3(1) or N1101.12.3(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 N1101.12.3(3).

TABLE N1101.12.3(1) [R303.1.3(1)]
DEFAULT GLAZED FENESTRATION U-FACTOR

FRAME TYPE SINGLE
PANE
DOUBLE
PANE
SKYLIGHT
SingleDouble
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 N1101.12.3(2) [R303.1.3(2)]
DEFAULT DOOR U-FACTORS

DOOR TYPEU-FACTOR
Uninsulated Metal1.20
Insulated Metal0.60
Wood0.50
Insulated, nonmetal edge, max 45% glazing, any glazing double pane0.35

TABLE N1101.12.3(3) [R303.1.3(3)]
DEFAULT GLAZED FENESTRATION SHGC AND VT

SINGLE GLAZEDDOUBLE GLAZEDGLAZED
BLOCK
ClearTinted ClearTinted
SHGC0.80.70.70.60.6
VT0.60.30.60.30.6
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).
All materials, systems and equipment shall be installed in accordance with the manufacturer's installation instructions and this code.
Insulation applied to the exterior of basement walls, crawlspace walls and the perimeter of slab-on-grade floors shall have a rigid, 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 a minimum of 6 inches (153 mm) below grade.
Maintenance instructions shall be furnished for equipment and systems that require preventive maintenance. Required regular maintenance actions shall be clearly stated and incorporated on a readily accessible label. The label shall include the title or publication number for the operation and maintenance manual for that particular model and type of product.
Projects shall comply with Sections identified as “mandatory” and with either sections identified as “prescriptive” or the performance approach in Section N1105.
A permanent certificate shall be completed and posted on or in the electrical distribution panel by the builder or registered design professional. The certificate shall not cover or obstruct the visibility of the circuit directory label, service disconnect label or other required labels. The certificate shall list the predominant R-values of insulation installed in or on ceiling/roof, walls, foundation (slab, basement wall, crawl space wall and/or floor) and ducts outside conditioned spaces; U-factors for fenestration and the solar heat gain coefficient (SHGC) of fenestration, and the results from any required duct system and building envelope air leakage testing done on the building. Where there is more than one value for each component, the certificate shall list the value covering the largest area. The certificate shall list the types and efficiencies of heating, cooling and service water heating equipment. Where a gas-fired unvented room heater, electric furnace, or baseboard electric heater is installed in the residence, the certificate shall list “gas-fired unvented room heater,” “electric furnace” or “baseboard electric heater,” as appropriate. An efficiency shall not be listed for gas-fired unvented room heaters, electric furnaces or electric baseboard heaters.
The building thermal envelope shall meet the requirements of Sections N1102.1.1 through N1102.1.4.
The building thermal envelope shall meet the requirements of Table N1102.1.1 based on the climate zone specified in Section N1101.10.

TABLE N1102.1.1 (R402.1.1)
INSULATION AND FENESTRATION REQUIREMENTS BY COMPONENTa

CLIMATE
ZONE
FENESTRATION
U-FACTORb
SKYLIGHTb
U-FACTOR
GLAZED
FENESTRATION
SHGCb, e
CEILING
R-VALUE
WOOD
FRAME WALL
R-VALUE
MASS WALL
R-VALUEi
FLOOR
R-VALUE
BASEMENTc
WALL
R-VALUE
SLABd
R-VALUE
& DEPTH
CRAWL
SPACEc
WALL
R-VALUE
1NR0.750.2530133/413000
20.400.650.2538134/613000
30.350.550.253820 or 13 + 5h8/13195/13f05/13
4 except Marine0.350.550.404920 or 13 + 5h8/131910 /1310, 2 ft10/13
5 and Marine 40.320.55NR4920 or 13 + 5h13/1730g15/1910, 2 ft15/19
60.320.55NR4920 + 5 or 13 + 10h15/2030g15/1910, 4 ft15/19
7 and 80.320.55NR4920 + 5 or 13 + 10h19/2138g15/1910, 4 ft15/19
For SI: 1 foot = 304.8 mm.
a. 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.
b. The fenestration U-factor column excludes skylights. The SHGC column applies to all glazed fenestration.
Exception: Skylights may be excluded from glazed fenestration SHGC requirements in Climate Zones 1 through 3 where the SHGC for such skylights does not exceed 0.30.
c. “15/19” means R-15 continuous insulation on the interior or exterior of the home or R-19 cavity insulation at the interior of the basement wall. “15/19” shall be permitted to be met with R-13 cavity insulation on the interior of the basement wall plus R-5 continuous insulation on the interior or exterior of the home. “10/13” means R-10 continuous insulation on the interior or exterior of the home or R-13 cavity insulation at the interior of the basement wall.
d. R-5 shall be added to the required slab edge R-values for heated slabs. Insulation depth shall be the depth of the footing or 2 feet, whichever is less in Zones 1 through 3 for heated slabs.
e. There are no SHGC requirements in the Marine Zone.
f. Basement wall insulation is not required in warm-humid locations as defined by Figure N1101.10 and Table N1101.10.
g. Or insulation sufficient to fill the framing cavity, R-19 minimum.
h. First value is cavity insulation, second is continuous insulation or insulated siding, so “13 + 5” means R-13 cavity insulation plus R-5 continuous insulation or insulated siding. If structural sheathing covers 40 percent or less of the exterior, continuous insulation R-value shall be permitted to be reduced by no more than R-3 in the locations where structural sheathing is used – to maintain a consistent total sheathing thickness.
i. The second R-value applies when more than half the insulation is on the interior of the mass wall.
Insulation material used in layers, such as framing cavity insulation and insulating sheathing, shall be summed to compute the 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.
An assembly with a U-factor equal to or less than that specified in Table N1102.1.3 shall be permitted as an alternative to the R-value in Table N1102.1.1.

TABLE N1102.1.3 (R402.1.3)
EQUIVALENT U-FACTORSa

CLIMATE
ZONE
FENESTRATION
U-FACTOR
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
10.500.750.0350.0820.1970.0640.3600.477
20.400.650.0300.0820.1650.0640.3600.477
30.350.550.0300.0570.0980.047 0.091c0.136
4 except Marine0.350.550.0260.0570.0980.0470.0590.065
5 and Marine 40.320.550.0260.0570.0820.0330.0500.055
60.320.550.0260.0480.0600.0330.0500.055
7 and 80.320.550.0260.0480.0570.0280.0500.055
a. Nonfenestration U-factors shall be obtained from measurement, calculation or an approved source.
b. When more than half the insulation is on the interior, the mass wall U-factors shall be a maximum of 0.17 in Zone 1, 0.14 in Zone 2, 0.12 in Zone 3, 0.087 in Zone 4 except Marine, 0.065 in Zone 5 and Marine 4, and 0.057 in Zones 6 through 8.
c. Basement wall U-factor of 0.360 in warm-humid locations as defined by Figure N1101.10 (R301.1) and Table N1101.10 (R301.1).
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 N1102.1.3 (multiplied by the same assembly area as in the proposed building), the building shall be considered in compliance with Table N1102.1.1. 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.
In addition to the requirements of Section N1102.1, insulation shall meet the specific requirements of Sections N1102.2.1 through N1102.2.12.
When Section N1102.1.1 would require R-38 in the ceiling, R-30 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. Similarly, R-38 shall be deemed to satisfy the requirement for R-49 wherever the full height of uncompressed R-38 insulation extends over the wall top plate at the eaves. This reduction shall not apply to the U-factor alternative approach in Section N1102.1.3 and the total UA alternative in Section N1102.1.4.
Where Section N1102.1.1 would require insulation levels above R-30 and the design of the roof/ceiling assembly 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 N1102.1.1 shall be limited to 500 square feet (46 m2) or 20 percent of the total insulated ceiling area, whichever is less. This reduction shall not apply to the U-factor alternative approach in Section N1102.1.3 and the total UA alternative in Section N1102.1.4.
For air permeable insulations in vented attics, a baffle shall be installed adjacent to soffit and eave vents. Baffles shall maintain an opening equal or greater than the size of the vent. The baffle shall extend over the top of the attic insulation. The baffle shall be permitted to be any solid material.
Access doors from conditioned spaces to unconditioned spaces (e.g., attics and crawl spaces) shall be weatherstripped and insulated to a level equivalent to the insulation on the surrounding surfaces. 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.
Mass walls for the purposes of this chapter shall be considered above-grade 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.
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 N1102.1.3. 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 o.c.
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 + 3R-0 + 11.2 or R-13 + 6.1 or R-15 + 5.7 or
R-19 + 5.0 or R-21 + 4.7
R-20R-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 + 5R-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 o.c.
R-13R-0 + 9.3 or R-13 + 3.0 or R-15 + 2.4
R-13 + 3R-0 + 11.2 or R-13 + 4.9 or R-15 + 4.3 or
R-19 + 3.5 or R-21 + 3.1
R-20R-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 + 5R-13 + 11.5 or R-15 + 10.9 or R-19 + 10.1 or
R-21 + 9.7 or R-25 + 9.1
R-21R-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-13R-19 in 2 × 6, or R-19 + 6 in 2 × 8 or 2 × 10
R-19R-19 + 6 in 2 × 6, or R-19 + 12 in 2 × 8 or 2 × 10
a. Cavity insulation R-value is listed first, followed by continuous insulation R-value.
b. Insulation exceeding the height of the framing shall cover the framing.
Floor insulation shall be installed to maintain permanent contact with the underside of the subfloor decking.
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 N1102.1.1 and N1102.2.7.
Slab-on-grade floors with a floor surface less than 12 inches (305 mm) below grade shall be insulated in accordance with Table N1102.1.1. The insulation shall extend downward from the top of the slab on the outside or inside of the foundation wall. Insulation located below grade shall be extended the distance provided in Table N1102.1.1 by any combination of vertical insulation, insulation extending under the slab or insulation extending out from the building. Insulation extending away from the building shall be protected by pavement or by a minimum of 10 inches (254 mm) of soil. 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 is not required in jurisdictions designated by the building official as having a very heavy termite infestation.
As an alternative to insulating floors over crawl spaces, crawl space walls shall be permitted to be insulated when the crawl space is not vented to the outside. Crawl space wall insulation shall be permanently fastened to the wall and extend downward from the floor to the finished grade level and then vertically and/or horizontally for at least an additional 24 inches (610 mm). Exposed earth in unvented crawl space foundations shall be covered with a continuous Class I vapor retarder in accordance with this code. All joints of the vapor retarder shall overlap by 6 inches (153 mm) and be sealed or taped. The edges of the vapor retarder shall extend at least 6 inches (153 mm) up the stem wall and shall be attached to the stem wall.
Insulation shall not be required on the horizontal portion of the foundation that supports a masonry veneer.
All 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 1 through 4 and R-24 in Zones 5 through 8; and
2. The minimum wall R-value shall be R-13 in all zones. Wall(s) separating a sunroom with a thermal isolation from conditioned space shall meet the building thermal envelope requirements of this code.
In addition to the requirements of Section N1102, fenestration shall comply with Sections N1102.3.1 through N1102.3.6.
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.
Up to 15 square feet (1.4 m2) of glazed fenestration per dwelling unit shall be permitted to be exempt from U-factor and SHGC requirements in Section N1102.1.1. This exemption shall not apply to the U-factor alternative approach in Section N1102.1.3 and the Total UA alternative in Section N1102.1.4.
One side-hinged opaque door assembly up to 24 square feet (2.22 m2) in area is exempted from the U-factor requirement in Section N1102.1.1. This exemption shall not apply to the U-factor alternative approach in Section N1102.1.3 and the total UA alternative in Section N1102.1.4.
All sunrooms enclosing conditioned spaces shall meet the fenestration requirements of this code.

Exception: For sunrooms with thermal isolation and enclosing conditioned spaces, in Zones 4 through 8, the following exceptions to the fenestration requirements of this code shall apply:

1. The maximum fenestration U-factor shall be 0.45; and
2. The maximum skylight U-factor shall be 0.70. New fenestration separating the sunroom with thermal isolation from conditioned space shall meet the building thermal envelope requirements of this code.
Where some or all of an existing fenestration unit is replaced with a new fenestration product, including sash and glazing, the replacement fenestration unit shall meet the applicable requirements for U-factor and SHGC in Table N1102.1.1.
The building thermal envelope shall be constructed to limit air leakage in accordance with the requirements of Sections N1102.4.1 through N1102.4.4.
The building thermal envelope shall comply with Sections N1102.4.1.1 and N1102.4.1.2. The sealing methods between dissimilar materials shall allow for differential expansion and contraction.
The components of the building thermal envelope as listed in Table N1102.4.1.1 shall be installed in accordance with the manufacturer's instructions and the criteria listed in Table N1102.4.1.1, as applicable to the method of construction. Where required by the building official, an approved third party shall inspect all components and verify compliance.

TABLE N1102.4.1.1 (R402.4.1.1)
AIR BARRIER AND INSULATION INSTALLATION

COMPONENT CRITERIAa
Air barrier and thermal barrier A continuous air barrier shall be installed in the building envelope.
Exterior thermal envelope contains a continuous air barrier.
Breaks or joints in the air barrier shall be sealed.
Air-permeable insulation shall not be used as a sealing material.
Ceiling/attic The air barrier in any dropped ceiling/soffit shall be aligned with the insulation and any gaps in the air barrier sealed.
Access openings, drop down stair or knee wall doors to unconditioned attic spaces shall be sealed.
Walls Corners and headers shall be insulated and the junction of the foundation and sill plate shall be sealed.
The junction of the top plate and top of exterior walls shall be sealed.
Exterior thermal envelope insulation for framed walls shall be installed in substantial contact and continuous alignment with the air barrier.
Knee walls shall be sealed.
Windows, skylights and doors The space between window/door jambs and framing and skylights and framing shall be sealed.
Rim joists Rim joists shall be insulated and include the air barrier.
Floors
(including above-garage and cantilevered floors)
Insulation shall be installed to maintain permanent contact with underside of subfloor decking.
The air barrier shall be installed at any exposed edge of insulation.
Crawl space walls Where provided in lieu of floor insulation, insulation shall be permanently attached to the crawlspace walls.
Exposed earth in unvented crawl spaces shall be covered with a Class I vapor retarder with overlapping joints taped.
Shafts, penetrations Duct shafts, utility penetrations, and flue shafts opening to exterior or unconditioned space shall be sealed.
Narrow cavities Batts in narrow cavities shall be cut to fit, or narrow cavities shall be filled by insulation that on installation readily conforms to the available cavity space.
Garage separation Air sealing shall be provided between the garage and conditioned spaces.
Recessed lighting Recessed light fixtures installed in the building thermal envelope shall be air tight, IC rated, and sealed to the drywall.
Plumbing and wiring Batt insulation shall be cut neatly to fit around wiring and plumbing in exterior walls, or insulation that on installation readily conforms to available space shall extend behind piping and wiring.
Shower/tub on exterior wall Exterior walls adjacent to showers and tubs shall be insulated and the air barrier installed separating them from the showers and tubs.
Electrical/phone box on exterior walls The air barrier shall be installed behind electrical or communication boxes or air-sealed boxes shall be installed.
HVAC register boots HVAC register boots that penetrate building thermal envelope shall be sealed to the subfloor or drywall.
Fireplace An air barrier shall be installed on fireplace walls. Fireplaces shall have gasketed doors.
a. In addition, inspection of log walls shall be in accordance with the provisions of ICC-400.
The building or dwelling unit shall be tested and verified as having an air leakage rate of not exceeding 5 air changes per hour in Zones 1 and 2, and 3 air changes per hour in Zones 3 through 8. Testing shall be conducted with a blower door at a pressure of 0.2 inches w.g. (50 Pascals). Where required by the building official, testing shall be conducted by an approved third party. A written report of the results of the test shall be signed by the party conducting the test and provided to the building official. Testing shall be performed at any time after creation of all penetrations of the building thermal envelope.

During testing:

1. Exterior windows and doors, fireplace and stove doors shall be closed, but not sealed, beyond the intended weatherstripping or other infiltration control measures;
2. Dampers including exhaust, intake, makeup air, backdraft and flue dampers shall be closed, but not sealed beyond intended infiltration control measures;
3. Interior doors, if installed at the time of the test, shall be open;
4. Exterior doors for continuous ventilation systems and heat recovery ventilators shall be closed and sealed;
5. Heating and cooling systems, if installed at the time of the test, shall be turned off; and
6. Supply and return registers, if installed at the time of the test, shall be fully open.
Deleted
New wood-burning fireplaces shall have tight-fitting flue dampers and outdoor combustion air.
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: Site-built windows, skylights and doors.

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.
The area-weighted average maximum fenestration U-factor permitted using tradeoffs from Section N1102.1.4 or N1105 shall be 0.48 in Zones 4 and 5 and 0.40 in Zones 6 through 8 for vertical fenestration, and 0.75 in Zones 4 through 8 for skylights. The area-weighted average maximum fenestration SHGC permitted using tradeoffs from Section N1105 in Zones 1 through 3 shall be 0.50.
At least one thermostat shall be provided for each separate heating and cooling system.
Where the primary heating system is a forced-air furnace, at least one thermostat per 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 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).
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.
Ducts and air handlers shall be in accordance with Sections N1103.2.1 through N1103.2.3.
Supply ducts in attics shall be insulated to a minimum of R-8. All other ducts shall be insulated to a minimum of R-6.

Exception: Ducts or portions thereof located completely inside the building thermal envelope.

Ducts, air handlers, and filter boxes 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.
2. Where a duct connection is made that is partially inaccessible, three screws or rivets shall be equally spaced on the exposed portion of the joint so as to prevent a hinge effect.
3. Continuously welded and locking-type longitudinal joints and seams in ducts operating at static pressures less than 2 inches of water column (500 Pa) pressure classification shall not require additional closure systems.
Duct tightness shall be verified by either of the following:
1. Postconstruction test: Total leakage shall be less than or equal to 4 cfm (113.3 L/min) per 100 square feet (9.29 m2) of conditioned floor area 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. All register boots shall be taped or otherwise sealed during the test.
2. Rough-in test: Total leakage shall be less than or equal to 4 cfm (113.3 L/min) per 100 ft2 (9.29 m2) of conditioned floor area when tested at a pressure differential of 0.1 inches w.g. (25 Pa) across the system, including the manufacturer's air handler enclosure. All registers shall be taped or otherwise sealed during the test. If the air handler is not installed at the time of the test, total leakage shall be less than or equal to 3 cfm (85 L/min) per 100 square feet (9.29 m2) of conditioned floor area.

Exception: The total leakage test is not required for ducts and air handlers located entirely within the building thermal envelope.

Air handlers shall have a manufacturer's designation for an air leakage of no more than 2 percent of the design air flow rate when tested in accordance with ASHRAE 193.
Building framing cavities shall not be used as ducts or 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.
Piping insulation exposed to weather shall be protected from damage, including that caused by sunlight, moisture, equipment maintenance, and wind, and shall provide shielding from solar radiation that can cause degradation of the material. Adhesive tape shall not be permitted.
Energy conservation measures for service hot water systems shall be in accordance with Sections N1103.4.1 and N1103.4.2.
Circulating hot water systems shall be provided with an automatic or readily accessible manual switch that can turn off the hot-water circulating pump when the system is not in use.
Insulation for hot water pipe with a minimum thermal resistance (R-value) of R-3 shall be applied to the following:
1. Piping larger than 3/4-inch nominal diameter.
2. Piping serving more than one dwelling unit.
3. Piping from the water heater to kitchen outlets.
4. Piping located outside the conditioned space.
5. Piping from the water heater to a distribution manifold.
6. Piping located under a floor slab.
7. Buried piping.
8. Supply and return piping in recirculation systems other than demand recirculation systems.
9. Piping with run lengths greater than the maximum run lengths for the nominal pipe diameter given in Table N1103.4.2.
All remaining piping shall be insulated to at least R-3 or meet the run length requirements of Table N1103.4.2.

TABLE N1103.4.2 (R403.4.2)
MAXIMUM RUN LENGTH (feet)a

Nominal pipe diameter of largest
diameter pipe in the run (inch)
3/81/23/4> 3/4
Maximum run length3020105
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm.
a. Total length of all piping from the distribution manifold or the recirculation loop to a point of use.
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.
When installed to function as a whole-house mechanical ventilation system fans shall meet the efficacy requirements of Table N1103.5.1.

Exception: Where whole-house mechanical ventilation fans are integral to tested and listed HVAC equipment, they shall be powered by an electronically commutated motor.

TABLE N1103.5.1 (R403.5.1)
MECHANICAL VENTILATION SYSTEM FAN EFFICACY

FAN LOCATIONAIR FLOW RATE MINIMUM
(CFM)
MINIMUM EFFICACYa
(CFM/WATT)
AIR FLOW RATE MAXIMUM
(CFM)
Range hoodsAny2.8 cfm/wattAny
In-line fanAny2.8 cfm/wattAny
Bathroom, utility room101.4 cfm/watt< 90
Bathroom, utility room902.8 cfm/wattAny
For SI: 1 cubic foot per minute = 28.3 L/min.
a. When tested in accordance with HVI Standard 916
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.
Systems serving multiple dwelling units shall comply with Sections C403 and C404 of the IECC—Commercial Provisions in lieu of Section N1103.
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), and no precipitation is falling and an automatic or manual control that will allow shutoff when the outdoor temperature is above 40°F (4.8°C).
Pools and inground permanently installed spas shall comply with Sections N1103.9.1 through N1103.9.3.
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 constant burning pilot lights.
Time switches or other control method that can automatically turn off and on heaters and pumps according to a preset schedule shall be installed on all heaters and pumps. Heaters, pumps and motors that have built in timers shall be deemed in compliance with this requirement.

Exceptions:

1. Where public health standards require 24-hour pump operation.
2. Where pumps are required to operate solar-and waste-heat-recovery pool heating systems.
Heated pools and inground permanently installed spas shall be provided with a vapor-retardant cover.

Exception: Pools deriving over 70 percent of the energy for heating from site-recovered energy, such as a heat pump or solar energy source computed over an operating season.

A minimum of 75 percent of the lamps in permanently installed lighting fixtures shall be high-efficacy lamps or a minimum of 75 percent of the permanently installed lighting fixtures shall contain only high-efficacy lamps.
Exception: Low-voltage lighting shall not be required to utilize high-efficiency lamps.
Fuel gas lighting systems shall not have continuously burning pilot lights.
This section establishes criteria for compliance using simulated energy performance analysis. Such analysis shall include heating, cooling, and service water heating energy only.
Compliance with this section requires that the mandatory provisions identified in Section N1101.15 be met. All supply and return ducts not completely inside the building thermal envelope shall be insulated to a minimum of R-6.
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.
Compliance software tools shall generate a report that documents that the proposed design complies with Section N1105.3. The compliance documentation shall include the following information:
1. Address or other identification of the residence;
2. An inspection checklist documenting the building component characteristics of the proposed design as listed in Table N1105.5.2(1). The inspection checklist shall show results for both the standard reference design and the proposed design, and shall document all inputs entered by the user necessary to reproduce the results;
3. Name of individual completing the compliance report; and
4. Name and version of the compliance software tool.

Exception: Multiple orientations. When an otherwise identical building model is offered in multiple orientations, compliance for any orientation shall be permitted by documenting that the building meets the performance requirements in each of the four cardinal (north, east, south and west) orientations.

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.
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 N1102.1.1.

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 wallsType: mass wall if proposed wall is mass; otherwise wood frame.
Gross area: same as proposed
U-factor: from Table N1102.1.3
Solar absorptance = 0.75
Remittance = 0.90
As proposed
As proposed
As proposed
As proposed
As proposed
Basement and crawl space wallsType: same as proposed
Gross area: same as proposed
U-factor: from Table N1102.1.3, with insulation layer on interior side of walls.
As proposed
As proposed
As proposed
Above-grade floorsType: wood frame
Gross area: same as proposed
U-factor: from Table N1102.1.3
As proposed
As proposed
As proposed
CeilingsType: wood frame
Gross area: same as proposed
U-factor: from Table N1102.1.3
As proposed
As proposed
As proposed
RoofsType: composition shingle on wood sheathing
Gross area: same as proposed
Solar absorptance = 0.75
Emittance = 0.90
As proposed
As proposed
As proposed
As proposed
AtticsType: vented with aperture = 1 ft2 per 300 ft2 ceiling areaAs proposed
FoundationsType: same as proposed foundation wall area above and below grade and soil characteristics: same as proposed.As proposed
As proposed
DoorsArea: 40 ft2
Orientation: North
U-factor: same as fenestration from Table N1102.1.3.
As proposed
As proposed
As proposed
GlazingaTotal areab =
(a) The proposed glazing area; where proposed glazing area is less than
15% of the conditioned floor area.
(b) 15% of the conditioned floor area; where the proposed glazing area is 15% or more of the conditioned floor area.
As proposed
Orientation: equally distributed to four cardinal compass orientations
(N, E, S & W).
As proposed
U-factor: from Table N1102.1.3 As proposed
SHGC: From Table N1102.1.1 except that for climates with no requirement
(NR) SHGC = 0.40 shall be used.
Interior shade fraction: 0.92-(0.21 × SHGC for the standard reference design)
External shading: none
As proposed
0.92-(0.21 × SHGC as proposed)
As proposed
SkylightsNoneAs proposed
Thermally isolated sunroomsNoneAs proposed

(continued)

TABLE N1105.5.2(1) [R405.5.2(1)]—continued
SPECIFICATIONS FOR THE STANDARD REFERENCE AND PROPOSED DESIGNS

BUILDING COMPONENTSTANDARD REFERENCE DESIGNPROPOSED DESIGN
Air exchange rate Air leakage rate of 5 air changes per hour in Zones 1 and 2, and 3 air changes per hour in Zones 3 through 8 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 ratec.
The mechanical ventilation rated 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 elemente but not
integral to the building envelope
or structure.
Structural mass For masonry floor slabs, 80% of floor area covered by R-2 carpet and pad, and 20% of floor directly exposed to room air.
For masonry basement walls, as proposed, but with insulation required by Table N1102.1.3 (R402.1.3) located on the interior side of the walls.
For other walls, for ceilings, floors, and interior walls, wood frame construction.

As proposed
As proposed
As proposed
Heating systems f, g 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 International Energy
Conservation Code—Commercial Provisions.
Capacity: sized in accordance with Section N1103.6
As proposed
Cooling systemsf, h As proposed
Capacity: sized in accordance with Section N1103.6.
As proposed
Service water
Heatingf, g, h, i
As proposed
Use: same as proposed design
As proposed
gal/day = 30 + (10 × Nbr)
Thermal distribution systems NoneThermal distribution system efficiency shall be as tested or as specified in Table N1105.5.2(2)
if not tested. Duct insulation
shall be as proposed.
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 (U.S.) = 3.785 L,
°C = (°F-3)/1.8, 1 degree = 0.79 rad, 1 inch water gauge = 1250 Pa.
a. Glazing shall be defined as sunlight-transmitting fenestration, including the area of sash, curbing or other framing elements, that enclose conditioned space. Glazing includes the area of sunlight-transmitting fenestration assemblies in walls bounding conditioned basements. For doors where the sunlight-transmitting opening is less than 50 percent of the door area, the glazing area is the sunlight transmitting opening area. For all other doors, the glazing area is the rough frame opening area for the door including the door and the frame.
b. 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.
c. Where required by the building 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.
d. 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.
e. 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.
f. 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.
g. 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.
h. 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.
i. 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.

TABLE N1105.5.2(2) [R405.5.2(2)]
DEFAULT DISTRIBUTION SYSTEM EFFICIENCIES FOR PROPOSED DESIGNSa

DISTRIBUTION SYSTEM CONFIGURATION AND CONDITIONFORCED AIR SYSTEMSHYDRONIC SYSTEMSb
Distribution system components located in unconditioned space 0.95
Untested distribution systems entirely located in conditioned spacec 0.881
“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 (e.g., R-value, U-factor, SHGC, HSPF, AFUE, SEER, EF, etc.).
Performance analysis tools meeting the applicable sections 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.
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