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Adopts Without Amendments:

International Residential Code 2012 (IRC 2012)

Part I — Administrative

Part II — Definitions

Part III — Building Planning and Construction

Part IV — Energy Conservation

Part V — Mechanical

Part VI — Fuel Gas

Part VII — Plumbing

Part VIII — Electrical

Part IX — Referenced Standards

Heads up: There are no amended sections in this chapter.
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.
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)
TABLE N1101.10 (R301.1)
Key: A — Moist, B — Dry, C — Marine. Absence of moisture designation indicates moisture regime is irrelevant.
Asterisk (*) indicates a warm-humid location. 
ALABAMA 3A Lee 7 Kodiak Island 4A Boone 3A Mississippi
3A Limestone 7 Lake and 3A Bradley 3A Monroe
3A Autauga* 3A Lowndes* Peninsula 3A Calhoun 3A Montgomery
2A Baldwin* 3A Macon* 7 Matanuska- 4A Carroll 3A Nevada
3A Barbour* 3A Madison Susitna 3A Chicot 4A Newton
3A Bibb 3A Marengo* 8 Nome 3A Clark 3A Ouachita
3A Blount 3A Marion 8 North Slope 3A Clay 3A Perry
3A Bullock* 3A Marshall 8 Northwest Arctic 3A Cleburne 3A Phillips
3A Butler* 2A Mobile* 7 Prince of Wales 3A Cleveland 3A Pike
3A Calhoun 3A Monroe* Outer Ketchikan 3A Columbia* 3A Poinsett
3A Chambers 3A Montgomery* 7 Sitka 3A Conway 3A Polk
3A Cherokee 3A Morgan 7 Skagway-Hoonah- 3A Craighead 3A Pope
3A Chilton 3A Perry* Angoon 3A Crawford 3A Prairie
3A Choctaw* 3A Pickens 8 Southeast 3A Crittenden 3A Pulaski
3A Clarke* 3A Pike* Fairbanks 3A Cross 3A Randolph
3A Clay 3A Randolph 7 Valdez-Cordova 3A Dallas 3A Saline
3A Cleburne 3A Russell* 8 Wade Hampton 3A Desha 3A Scott
3A Coffee* 3A Shelby 7 Wrangell- 3A Drew 4A Searcy
3A Colbert 3A St. Clair Petersburg 3A Faulkner 3A Sebastian
3A Conecuh* 3A Sumter 7 Yakutat 3A Franklin 3A Sevier*
3A Coosa 3A Talladega 8 Yukon-Koyukuk 4A Fulton 3A Sharp
3A Covington* 3A Tallapoosa ARIZONA 3A Garland 3A St. Francis
3A Crenshaw* 3A Tuscaloosa 3A Grant 4A Stone
3A Cullman 3A Walker 5B Apache 3A Greene 3A Union*
3A Dale* 3A Washington* 3B Cochise 3A Hempstead* 3A Van Buren
3A Dallas* 3A Wilcox* 5B Coconino 3A Hot Spring 4A Washington
3A DeKalb 3A Winston 4B Gila 3A Howard 3A White
3A Elmore* ALASKA 3B Graham 3A Independence 3A Woodruff
3A Escambia* 3B Greenlee 4A Izard 3A Yell
3A Etowah 7 Aleutians East 2B La Paz 3A Jackson CALIFORNIA
3A Fayette 7 Aleutians West 2B Maricopa 3A Jefferson
3A Franklin 7 Anchorage 3B Mohave 3A Johnson 3C Alameda
3A Geneva* 8 Bethel 5B Navajo 3A Lafayette* 6B Alpine
3A Greene 7 Bristol Bay 2B Pima 3A Lawrence 4B Amador
3A Hale 7 Denali 2B Pinal 3A Lee 3B Butte
3A Henry* 8 Dillingham 3B Santa Cruz 3A Lincoln 4B Calaveras
3A Houston* 8 Fairbanks North 4B Yavapai 3A Little River* 3B Colusa
3A Jackson Star 2B Yuma 3A Logan 3B Contra Costa
3A Jefferson 7 Haines ARKANSAS 3A Lonoke 4C Del Norte
3A Lamar 7 Juneau 4A Madison 4B El Dorado
3A Lauderdale 7 Kenai Peninsula 3A Arkansas 4A Marion 3B Fresno
3A Lawrence 7 Ketchikan 3A Ashley 3A Miller* 3B Glenn
  Gateway 4A Baxter    
    4A Benton    
TABLE N1101.10 (R301.1)—continued
4C Humboldt 3B Yuba 5B Morgan 2A Escambia* 2A Taylor*
2B Imperial COLORADO 4B Otero 2A Flagler* 2A Union*
4B Inyo 6B Ouray 2A Franklin* 2A Volusia*
3B Kern 5B Adams 7 Park 2A Gadsden* 2A Wakulla*
3B Kings 6B Alamosa 5B Phillips 2A Gilchrist* 2A Walton*
4B Lake 5B Arapahoe 7 Pitkin 2A Glades* 2A Washington*
5B Lassen 6B Archuleta 5B Prowers 2A Gulf* GEORGIA
3B Los Angeles 4B Baca 5B Pueblo 2A Hamilton*
3B Madera 5B Bent 6B Rio Blanco 2A Hardee* 2A Appling*
3C Marin 5B Boulder 7 Rio Grande 2A Hendry* 2A Atkinson*
4B Mariposa 6B Chaffee 7 Routt 2A Hernando* 2A Bacon*
3C Mendocino 5B Cheyenne 6B Saguache 2A Highlands* 2A Baker*
3B Merced 7 Clear Creek 7 San Juan 2A Hillsborough* 3A Baldwin
5B Modoc 6B Conejos 6B San Miguel 2A Holmes* 4A Banks
6B Mono 6B Costilla 5B Sedgwick 2A Indian River* 3A Barrow
3C Monterey 5B Crowley 7 Summit 2A Jackson* 3A Bartow
3C Napa 6B Custer 5B Teller 2A Jefferson* 3A Ben Hill*
5B Nevada 5B Delta 5B Washington 2A Lafayette* 2A Berrien*
3B Orange 5B Denver 5B Weld 2A Lake* 3A Bibb
3B Placer 6B Dolores 5B Yuma 2A Lee* 3A Bleckley*
5B Plumas 5B Douglas CONNECTICUT 2A Leon* 2A Brantley*
3B Riverside 6B Eagle 2A Levy* 2A Brooks*
3B Sacramento 5B Elbert 5A (all) 2A Liberty* 2A Bryan*
3C San Benito 5B El Paso DELAWARE 2A Madison* 3A Bulloch*
3B San Bernardino 5B Fremont 2A Manatee* 3A Burke
3B San Diego 5B Garfield 4A (all) 2A Marion* 3A Butts
3C San Francisco 5B Gilpin DISTRICT OF
2A Martin* 3A Calhoun*
3B San Joaquin 7 Grand 1A Miami-Dade* 2A Camden*
3C San Luis Obispo 7 Gunnison 4A (all) 1A Monroe* 3A Candler*
3C San Mateo 7 Hinsdale FLORIDA 2A Nassau* 3A Carroll
3C Santa Barbara 5B Huerfano 2A Okaloosa* 4A Catoosa
3C Santa Clara 7 Jackson 2A Alachua* 2A Okeechobee* 2A Charlton*
3C Santa Cruz 5B Jefferson 2A Baker* 2A Orange* 2A Chatham*
3B Shasta 5B Kiowa 2A Bay* 2A Osceola* 3A Chattahoochee*
5B Sierra 5B Kit Carson 2A Bradford* 2A Palm Beach* 4A Chattooga
5B Siskiyou 7 Lake 2A Brevard* 2A Pasco* 3A Cherokee
3B Solano 5B La Plata 1A Broward* 2A Pinellas* 3A Clarke
3C Sonoma 5B Larimer 2A Calhoun* 2A Polk* 3A Clay*
3B Stanislaus 4B Las Animas 2A Charlotte* 2A Putnam* 3A Clayton
3B Sutter 5B Lincoln 2A Citrus* 2A Santa Rosa* 2A Clinch*
3B Tehama 5B Logan 2A Clay* 2A Sarasota* 3A Cobb
4B Trinity 5B Mesa 2A Collier* 2A Seminole* 3A Coffee*
3B Tulare 7 Mineral 2A Columbia* 2A St. Johns* 2A Colquitt*
4B Tuolumne 6B Moffat 2A DeSoto* 2A St. Lucie* 3A Columbia
3C Ventura 5B Montezuma 2A Dixie* 2A Sumter* 2A Cook*
3B Yolo 5B Montrose 2A Duval* 2A Suwannee* 3A Coweta
TABLE N1101.10 (R301.1)—continued
3A Crawford 2A Lanier* 3A Taylor* 5B Cassia 4A Crawford
3A Crisp* 3A Laurens* 3A Telfair* 6B Clark 5A Cumberland
4A Dade 3A Lee* 3A Terrell* 5B Clearwater 5A DeKalb
4A Dawson 2A Liberty* 2A Thomas* 6B Custer 5A De Witt
2A Decatur* 3A Lincoln 3A Tift* 5B Elmore 5A Douglas
3A DeKalb 2A Long* 2A Toombs* 6B Franklin 5A DuPage
3A Dodge* 2A Lowndes* 4A Towns 6B Fremont 5A Edgar
3A Dooly* 4A Lumpkin 3A Treutlen* 5B Gem 4A Edwards
3A Dougherty* 3A Macon* 3A Troup 5B Gooding 4A Effingham
3A Douglas 3A Madison 3A Turner* 5B Idaho 4A Fayette
3A Early* 3A Marion* 3A Twiggs* 6B Jefferson 5A Ford
2A Echols* 3A McDuffie 4A Union 5B Jerome 4A Franklin
2A Effingham* 2A McIntosh* 3A Upson 5B Kootenai 5A Fulton
3A Elbert 3A Meriwether 4A Walker 5B Latah 4A Gallatin
3A Emanuel* 2A Miller* 3A Walton 6B Lemhi 5A Greene
2A Evans* 2A Mitchell* 2A Ware* 5B Lewis 5A Grundy
4A Fannin 3A Monroe 3A Warren 5B Lincoln 4A Hamilton
3A Fayette 3A Montgomery* 3A Washington 6B Madison 5A Hancock
4A Floyd 3A Morgan 2A Wayne* 5B Minidoka 4A Hardin
3A Forsyth 4A Murray 3A Webster* 5B Nez Perce 5A Henderson
4A Franklin 3A Muscogee 3A Wheeler* 6B Oneida 5A Henry
3A Fulton 3A Newton 4A White 5B Owyhee 5A Iroquois
4A Gilmer 3A Oconee 4A Whitfield 5B Payette 4A Jackson
3A Glascock 3A Oglethorpe 3A Wilcox* 5B Power 4A Jasper
2A Glynn* 3A Paulding 3A Wilkes 5B Shoshone 4A Jefferson
4A Gordon 3A Peach* 3A Wilkinson 6B Teton 5A Jersey
2A Grady* 4A Pickens 3A Worth* 5B Twin Falls 5A Jo Daviess
3A Greene 2A Pierce* HAWAII 6B Valley 4A Johnson
3A Gwinnett 3A Pike 5B Washington 5A Kane
4A Habersham 3A Polk 1A (all)* ILLINOIS 5A Kankakee
4A Hall 3A Pulaski* IDAHO 5A Kendall
3A Hancock 3A Putnam 5A Adams 5A Knox
3A Haralson 3A Quitman* 5B Ada 4A Alexander 5A Lake
3A Harris 4A Rabun 6B Adams 4A Bond 5A La Salle
3A Hart 3A Randolph* 6B Bannock 5A Boone 4A Lawrence
3A Heard 3A Richmond 6B Bear Lake 5A Brown 5A Lee
3A Henry 3A Rockdale 5B Benewah 5A Bureau 5A Livingston
3A Houston* 3A Schley* 6B Bingham 5A Calhoun 5A Logan
3A Irwin* 3A Screven* 6B Blaine 5A Carroll 5A Macon
3A Jackson 2A Seminole* 6B Boise 5A Cass 4A Macoupin
3A Jasper 3A Spalding 6B Bonner 5A Champaign 4A Madison
2A Jeff Davis* 4A Stephens 6B Bonneville 4A Christian 4A Marion
3A Jefferson 3A Stewart* 6B Boundary 5A Clark 5A Marshall
3A Jenkins* 3A Sumter* 6B Butte 4A Clay 5A Mason
3A Johnson* 3A Talbot 6B Camas 4A Clinton 4A Massac
3A Jones 3A Taliaferro 5B Canyon 5A Coles 5A McDonough
3A Lamar 2A Tattnall* 6B Caribou 5A Cook 5A McHenry
TABLE N1101.10 (R301.1)—continued
5A McLean 5A Boone 5A Miami 5A Appanoose 5A Jasper
5A Menard 4A Brown 4A Monroe 5A Audubon 5A Jefferson
5A Mercer 5A Carroll 5A Montgomery 5A Benton 5A Johnson
4A Monroe 5A Cass 5A Morgan 6A Black Hawk 5A Jones
4A Montgomery 4A Clark 5A Newton 5A Boone 5A Keokuk
5A Morgan 5A Clay 5A Noble 6A Bremer 6A Kossuth
5A Moultrie 5A Clinton 4A Ohio 6A Buchanan 5A Lee
5A Ogle 4A Crawford 4A Orange 6A Buena Vista 5A Linn
5A Peoria 4A Daviess 5A Owen 6A Butler 5A Louisa
4A Perry 4A Dearborn 5A Parke 6A Calhoun 5A Lucas
5A Piatt 5A Decatur 4A Perry 5A Carroll 6A Lyon
5A Pike 5A De Kalb 4A Pike 5A Cass 5A Madison
4A Pope 5A Delaware 5A Porter 5A Cedar 5A Mahaska
4A Pulaski 4A Dubois 4A Posey 6A Cerro Gordo 5A Marion
5A Putnam 5A Elkhart 5A Pulaski 6A Cherokee 5A Marshall
4A Randolph 5A Fayette 5A Putnam 6A Chickasaw 5A Mills
4A Richland 4A Floyd 5A Randolph 5A Clarke 6A Mitchell
5A Rock Island 5A Fountain 4A Ripley 6A Clay 5A Monona
4A Saline 5A Franklin 5A Rush 6A Clayton 5A Monroe
5A Sangamon 5A Fulton 4A Scott 5A Clinton 5A Montgomery
5A Schuyler 4A Gibson 5A Shelby 5A Crawford 5A Muscatine
5A Scott 5A Grant 4A Spencer 5A Dallas 6A O'Brien
4A Shelby 4A Greene 5A Starke 5A Davis 6A Osceola
5A Stark 5A Hamilton 5A Steuben 5A Decatur 5A Page
4A St. Clair 5A Hancock 5A St. Joseph 6A Delaware 6A Palo Alto
5A Stephenson 4A Harrison 4A Sullivan 5A Des Moines 6A Plymouth
5A Tazewell 5A Hendricks 4A Switzerland 6A Dickinson 6A Pocahontas
4A Union 5A Henry 5A Tippecanoe 5A Dubuque 5A Polk
5A Vermilion 5A Howard 5A Tipton 6A Emmet 5A Pottawattamie
4A Wabash 5A Huntington 5A Union 6A Fayette 5A Poweshiek
5A Warren 4A Jackson 4A Vanderburgh 6A Floyd 5A Ringgold
4A Washington 5A Jasper 5A Vermillion 6A Franklin 6A Sac
4A Wayne 5A Jay 5A Vigo 5A Fremont 5A Scott
4A White 4A Jefferson 5A Wabash 5A Greene 5A Shelby
5A Whiteside 4A Jennings 5A Warren 6A Grundy 6A Sioux
5A Will 5A Johnson 4A Warrick 5A Guthrie 5A Story
4A Williamson 4A Knox 4A Washington 6A Hamilton 5A Tama
5A Winnebago 5A Kosciusko 5A Wayne 6A Hancock 5A Taylor
5A Woodford 5A Lagrange 5A Wells 6A Hardin 5A Union
INDIANA 5A Lake 5A White 5A Harrison 5A Van Buren
5A La Porte 5A Whitley 5A Henry 5A Wapello
5A Adams 4A Lawrence IOWA 6A Howard 5A Warren
5A Allen 5A Madison 6A Humboldt 5A Washington
5A Bartholomew 5A Marion 5A Adair 6A Ida 5A Wayne
5A Benton 5A Marshall 5A Adams 5A Iowa 6A Webster
5A Blackford 4A Martin 6A Allamakee 5A Jackson 6A Winnebago
TABLE N1101.10 (R301.1)—continued
6A Winneshiek 4A Hodgeman 4A Seward 2A Iberville* 6A Cumberland
5A Woodbury 4A Jackson 4A Shawnee 3A Jackson* 6A Franklin
6A Worth 4A Jefferson 5A Sheridan 2A Jefferson* 6A Hancock
6A Wright 5A Jewell 5A Sherman 2A Jefferson Davis 6A Kennebec
KANSAS 4A Johnson 5A Smith 2A Lafayette* 6A Knox
4A Kearny 4A Stafford 2A Lafourche* 6A Lincoln
4A Allen 4A Kingman 4A Stanton 3A La Salle* 6A Oxford
4A Anderson 4A Kiowa 4A Stevens 3A Lincoln* 6A Penobscot
4A Atchison 4A Labette 4A Sumner 2A Livingston* 6A Piscataquis
4A Barber 5A Lane 5A Thomas 3A Madison* 6A Sagadahoc
4A Barton 4A Leavenworth 5A Trego 3A Morehouse 6A Somerset
4A Bourbon 4A Lincoln 4A Wabaunsee 3A Natchitoches* 6A Waldo
4A Brown 4A Linn 5A Wallace 2A Orleans* 6A Washington
4A Butler 5A Logan 4A Washington 3A Ouachita* 6A York
4A Chase 4A Lyon 5A Wichita 2A Plaquemines* MARYLAND
4A Chautauqua 4A Marion 4A Wilson 2A Pointe Coupee*
4A Cherokee 4A Marshall 4A Woodson 2A Rapides* 4A Allegany
5A Cheyenne 4A McPherson 4A Wyandotte 3A Red River* 4A Anne Arundel
4A Clark 4A Meade KENTUCKY 3A Richland* 4A Baltimore
4A Clay 4A Miami 3A Sabine* 4A Baltimore (city)
5A Cloud 5A Mitchell 4A (all) 2A St. Bernard* 4A Calvert
4A Coffey 4A Montgomery LOUISIANA 2A St. Charles* 4A Caroline
4A Comanche 4A Morris 2A St. Helena* 4A Carroll
4A Cowley 4A Morton 2A Acadia* 2A St. James* 4A Cecil
4A Crawford 4A Nemaha 2A Allen* 2A St. John the 4A Charles
5A Decatur 4A Neosho 2A Ascension* Baptist* 4A Dorchester
4A Dickinson 5A Ness 2A Assumption* 2A St. Landry* 4A Frederick
4A Doniphan 5A Norton 2A Avoyelles* 2A St. Martin* 5A Garrett
4A Douglas 4A Osage 2A Beauregard* 2A St. Mary* 4A Harford
4A Edwards 5A Osborne 3A Bienville* 2A St. Tammany* 4A Howard
4A Elk 4A Ottawa 3A Bossier* 2A Tangipahoa* 4A Kent
5A Ellis 4A Pawnee 3A Caddo* 3A Tensas* 4A Montgomery
4A Ellsworth 5A Phillips 2A Calcasieu* 2A Terrebonne* 4A Prince George's
4A Finney 4A Pottawatomie 3A Caldwell* 3A Union* 4A Queen Anne's
4A Ford 4A Pratt 2A Cameron* 2A Vermilion* 4A Somerset
4A Franklin 5A Rawlins 3A Catahoula* 3A Vernon* 4A St. Mary's
4A Geary 4A Reno 3A Claiborne* 2A Washington* 4A Talbot
5A Gove 5A Republic 3A Concordia* 3A Webster* 4A Washington
5A Graham 4A Rice 3A De Soto* 2A West Baton 4A Wicomico
4A Grant 4A Riley 2A East Baton Rouge* 4A Worcester
4A Gray 5A Rooks Rouge* 3A West Carroll MASSACHSETTS
5A Greeley 4A Rush 3A East Carroll 2A West Feliciana*
4A Greenwood 4A Russell 2A East Feliciana* 3A Winn* 5A (all)
5A Hamilton 4A Saline 2A Evangeline* MAINE MICHIGAN
4A Harper 5A Scott 3A Franklin*
4A Harvey 4A Sedgwick 3A Grant* 6A Androscoggin 6A Alcona
4A Haskell   2A Iberia* 7 Aroostook 6A Alger
TABLE N1101.10 (R301.1)—continued
5A Allegan 7 Mackinac 6A Carver 7 Otter Tail 3A Clay
6A Alpena 5A Macomb 7 Cass 7 Pennington 3A Coahoma
6A Antrim 6A Manistee 6A Chippewa 7 Pine 3A Copiah*
6A Arenac 6A Marquette 6A Chisago 6A Pipestone 3A Covington*
7 Baraga 6A Mason 7 Clay 7 Polk 3A DeSoto
5A Barry 6A Mecosta 7 Clearwater 6A Pope 3A Forrest*
5A Bay 6A Menominee 7 Cook 6A Ramsey 3A Franklin*
6A Benzie 5A Midland 6A Cottonwood 7 Red Lake 3A George*
5A Berrien 6A Missaukee 7 Crow Wing 6A Redwood 3A Greene*
5A Branch 5A Monroe 6A Dakota 6A Renville 3A Grenada
5A Calhoun 5A Montcalm 6A Dodge 6A Rice 2A Hancock*
5A Cass 6A Montmorency 6A Douglas 6A Rock 2A Harrison*
6A Charlevoix 5A Muskegon 6A Faribault 7 Roseau 3A Hinds*
6A Cheboygan 6A Newaygo 6A Fillmore 6A Scott 3A Holmes
7 Chippewa 5A Oakland 6A Freeborn 6A Sherburne 3A Humphreys
6A Clare 6A Oceana 6A Goodhue 6A Sibley 3A Issaquena
5A Clinton 6A Ogemaw 7 Grant 6A Stearns 3A Itawamba
6A Crawford 7 Ontonagon 6A Hennepin 6A Steele 2A Jackson*
6A Delta 6A Osceola 6A Houston 6A Stevens 3A Jasper
6A Dickinson 6A Oscoda 7 Hubbard 7 St. Louis 3A Jefferson*
5A Eaton 6A Otsego 6A Isanti 6A Swift 3A Jefferson Davis*
6A Emmet 5A Ottawa 7 Itasca 6A Todd 3A Jones*
5A Genesee 6A Presque Isle 6A Jackson 6A Traverse 3A Kemper
6A Gladwin 6A Roscommon 7 Kanabec 6A Wabasha 3A Lafayette
7 Gogebic 5A Saginaw 6A Kandiyohi 7 Wadena 3A Lamar*
6A Grand Traverse 6A Sanilac 7 Kittson 6A Waseca 3A Lauderdale
5A Gratiot 7 Schoolcraft 7 Koochiching 6A Washington 3A Lawrence*
5A Hillsdale 5A Shiawassee 6A Lac qui Parle 6A Watonwan 3A Leake
7 Houghton 5A St. Clair 7 Lake 7 Wilkin 3A Lee
6A Huron 5A St. Joseph 7 Lake of the Woods 6A Winona 3A Leflore
5A Ingham 5A Tuscola 6A Le Sueur 6A Wright 3A Lincoln*
5A Ionia 5A Van Buren 6A Lincoln 6A Yellow Medicine 3A Lowndes
6A Iosco 5A Washtenaw 6A Lyon MISSISSIPPI 3A Madison
7 Iron 5A Wayne 7 Mahnomen 3A Marion*
6A Isabella 6A Wexford 7 Marshall 3A Adams* 3A Marshall
5A Jackson MINNESOTA 6A Martin 3A Alcorn 3A Monroe
5A Kalamazoo 6A McLeod 3A Amite* 3A Montgomery
6A Kalkaska 7 Aitkin 6A Meeker 3A Attala 3A Neshoba
5A Kent 6A Anoka 7 Mille Lacs 3A Benton 3A Newton
7 Keweenaw 7 Becker 6A Morrison 3A Bolivar 3A Noxubee
6A Lake 7 Beltrami 6A Mower 3A Calhoun 3A Oktibbeha
5A Lapeer 6A Benton 6A Murray 3A Carroll 3A Panola
6A Leelanau 6A Big Stone 6A Nicollet 3A Chickasaw 2A Pearl River*
5A Lenawee 6A Blue Earth 6A Nobles 3A Choctaw 3A Perry*
5A Livingston 6A Brown 7 Norman 3A Claiborne* 3A Pike*
7 Luce 7 Carlton 6A Olmsted 3A Clarke  
TABLE N1101.10 (R301.1)—continued
3A Pontotoc 5A Chariton 4A Mississippi 4A Webster 4A Cumberland
3A Prentiss 4A Christian 4A Moniteau 5A Worth 4A Essex
3A Quitman 5A Clark 4A Monroe 4A Wright 4A Gloucester
3A Rankin* 4A Clay 4A Montgomery MONTANA 4A Hudson
3A Scott 5A Clinton 4A Morgan 5A Hunterdon
3A Sharkey 4A Cole 4A New Madrid 6B (all) 5A Mercer
3A Simpson* 4A Cooper 4A Newton NEBRASKA 4A Middlesex
3A Smith* 4A Crawford 5A Nodaway 4A Monmouth
2A Stone* 4A Dade 4A Oregon 5A (all) 5A Morris
3A Sunflower 4A Dallas 4A Osage NEVADA 4A Ocean
3A Tallahatchie 5A Daviess 4A Ozark 5A Passaic
3A Tate 5A DeKalb 4A Pemiscot 5B Carson City (city) 4A Salem
3A Tippah 4A Dent 4A Perry 5B Churchill 5A Somerset
3A Tishomingo 4A Douglas 4A Pettis 3B Clark 5A Sussex
3A Tunica 4A Dunklin 4A Phelps 5B Douglas 4A Union
3A Union 4A Franklin 5A Pike 5B Elko 5A Warren
3A Walthall* 4A Gasconade 4A Platte 5B Esmeralda NEW MEXICO
3A Warren* 5A Gentry 4A Polk 5B Eureka
3A Washington 4A Greene 4A Pulaski 5B Humboldt 4B Bernalillo
3A Wayne* 5A Grundy 5A Putnam 5B Lander 5B Catron
3A Webster 5A Harrison 5A Ralls 5B Lincoln 3B Chaves
3A Wilkinson* 4A Henry 4A Randolph 5B Lyon 4B Cibola
3A Winston 4A Hickory 4A Ray 5B Mineral 5B Colfax
3A Yalobusha 5A Holt 4A Reynolds 5B Nye 4B Curry
3A Yazoo 4A Howard 4A Ripley 5B Pershing 4B DeBaca
MISSOURI 4A Howell 4A Saline 5B Storey 3B Dona Ana
4A Iron 5A Schuyler 5B Washoe 3B Eddy
5A Adair 4A Jackson 5A Scotland 5B White Pine 4B Grant
5A Andrew 4A Jasper 4A Scott NEW
4B Guadalupe
5A Atchison 4A Jefferson 4A Shannon 5B Harding
4A Audrain 4A Johnson 5A Shelby 6A Belknap 3B Hidalgo
4A Barry 5A Knox 4A St. Charles 6A Carroll 3B Lea
4A Barton 4A Laclede 4A St. Clair 5A Cheshire 4B Lincoln
4A Bates 4A Lafayette 4A Ste. Genevieve 6A Coos 5B Los Alamos
4A Benton 4A Lawrence 4A St. Francois 6A Grafton 3B Luna
4A Bollinger 5A Lewis 4A St. Louis 5A Hillsborough 5B McKinley
4A Boone 4A Lincoln 4A St. Louis (city) 6A Merrimack 5B Mora
5A Buchanan 5A Linn 4A Stoddard 5A Rockingham 3B Otero
4A Butler 5A Livingston 4A Stone 5A Strafford 4B Quay
5A Caldwell 5A Macon 5A Sullivan 6A Sullivan 5B Rio Arriba
4A Callaway 4A Madison 4A Taney NEW JERSEY 4B Roosevelt
4A Camden 4A Maries 4A Texas 5B Sandoval
4A Cape Girardeau 5A Marion 4A Vernon 4A Atlantic 5B San Juan
4A Carroll 4A McDonald 4A Warren 5A Bergen 5B San Miguel
4A Carter 5A Mercer 4A Washington 4A Burlington 5B Santa Fe
4A Cass 4A Miller 4A Wayne 4A Camden 4B Sierra
4A Cedar     4A Cape May 4B Socorro
TABLE N1101.10 (R301.1)—continued
5B Taos 4A Queens 4A Clay 4A Orange 7 Divide
5B Torrance 5A Rensselaer 4A Cleveland 3A Pamlico 6A Dunn
4B Union 4A Richmond 3A Columbus* 3A Pasquotank 7 Eddy
4B Valencia 5A Rockland 3A Craven 3A Pender* 6A Emmons
NEW YORK 5A Saratoga 3A Cumberland 3A Perquimans 7 Foster
5A Schenectady 3A Currituck 4A Person 6A Golden Valley
5A Albany 6A Schoharie 3A Dare 3A Pitt 7 Grand Forks
6A Allegany 6A Schuyler 3A Davidson 4A Polk 6A Grant
4A Bronx 5A Seneca 4A Davie 3A Randolph 7 Griggs
6A Broome 6A Steuben 3A Duplin 3A Richmond 6A Hettinger
6A Cattaraugus 6A St. Lawrence 4A Durham 3A Robeson 7 Kidder
5A Cayuga 4A Suffolk 3A Edgecombe 4A Rockingham 6A LaMoure
5A Chautauqua 6A Sullivan 4A Forsyth 3A Rowan 6A Logan
5A Chemung 5A Tioga 4A Franklin 4A Rutherford 7 McHenry
6A Chenango 6A Tompkins 3A Gaston 3A Sampson 6A McIntosh
6A Clinton 6A Ulster 4A Gates 3A Scotland 6A McKenzie
5A Columbia 6A Warren 4A Graham 3A Stanly 7 McLean
5A Cortland 5A Washington 4A Granville 4A Stokes 6A Mercer
6A Delaware 5A Wayne 3A Greene 4A Surry 6A Morton
5A Dutchess 4A Westchester 4A Guilford 4A Swain 7 Mountrail
5A Erie 6A Wyoming 4A Halifax 4A Transylvania 7 Nelson
6A Essex 5A Yates 4A Harnett 3A Tyrrell 6A Oliver
6A Franklin NORTH
4A Haywood 3A Union 7 Pembina
6A Fulton 4A Henderson 4A Vance 7 Pierce
5A Genesee 4A Alamance 4A Hertford 4A Wake 7 Ramsey
5A Greene 4A Alexander 3A Hoke 4A Warren 6A Ransom
6A Hamilton 5A Alleghany 3A Hyde 3A Washington 7 Renville
6A Herkimer 3A Anson 4A Iredell 5A Watauga 6A Richland
6A Jefferson 5A Ashe 4A Jackson 3A Wayne 7 Rolette
4A Kings 5A Avery 3A Johnston 4A Wilkes 6A Sargent
6A Lewis 3A Beaufort 3A Jones 3A Wilson 7 Sheridan
5A Livingston 4A Bertie 4A Lee 4A Yadkin 6A Sioux
6A Madison 3A Bladen 3A Lenoir 5A Yancey 6A Slope
5A Monroe 3A Brunswick* 4A Lincoln NORTH DAKOTA 6A Stark
6A Montgomery 4A Buncombe 4A Macon 7 Steele
4A Nassau 4A Burke 4A Madison 6A Adams 7 Stutsman
4A New York 3A Cabarrus 3A Martin 7 Barnes 7 Towner
5A Niagara 4A Caldwell 4A McDowell 7 Benson 7 Traill
6A Oneida 3A Camden 3A Mecklenburg 6A Billings 7 Walsh
5A Onondaga 3A Carteret* 5A Mitchell 7 Bottineau 7 Ward
5A Ontario 4A Caswell 3A Montgomery 6A Bowman 7 Wells
5A Orange 4A Catawba 3A Moore 7 Burke 7 Williams
5A Orleans 4A Chatham 4A Nash 6A Burleigh OHIO
5A Oswego 4A Cherokee 3A New Hanover* 7 Cass
6A Otsego 3A Chowan 4A Northampton 7 Cavalier 4A Adams
5A Putnam   3A Onslow* 6A Dickey 5A Allen
TABLE N1101.10 (R301.1)—continued
5A Ashland 5A Mahoning 3A Bryan 3A Okfuskee 4C Linn
5A Ashtabula 5A Marion 3A Caddo 3A Oklahoma 5B Malheur
5A Athens 5A Medina 3A Canadian 3A Okmulgee 4C Marion
5A Auglaize 5A Meigs 3A Carter 3A Osage 5B Morrow
5A Belmont 5A Mercer 3A Cherokee 3A Ottawa 4C Multnomah
4A Brown 5A Miami 3A Choctaw 3A Pawnee 4C Polk
5A Butler 5A Monroe 4B Cimarron 3A Payne 5B Sherman
5A Carroll 5A Montgomery 3A Cleveland 3A Pittsburg 4C Tillamook
5A Champaign 5A Morgan 3A Coal 3A Pontotoc 5B Umatilla
5A Clark 5A Morrow 3A Comanche 3A Pottawatomie 5B Union
4A Clermont 5A Muskingum 3A Cotton 3A Pushmataha 5B Wallowa
5A Clinton 5A Noble 3A Craig 3A Roger Mills 5B Wasco
5A Columbiana 5A Ottawa 3A Creek 3A Rogers 4C Washington
5A Coshocton 5A Paulding 3A Custer 3A Seminole 5B Wheeler
5A Crawford 5A Perry 3A Delaware 3A Sequoyah 4C Yamhill
5A Cuyahoga 5A Pickaway 3A Dewey 3A Stephens PENNSYLVANIA
5A Darke 4A Pike 3A Ellis 4B Texas
5A Defiance 5A Portage 3A Garfield 3A Tillman 5A Adams
5A Delaware 5A Preble 3A Garvin 3A Tulsa 5A Allegheny
5A Erie 5A Putnam 3A Grady 3A Wagoner 5A Armstrong
5A Fairfield 5A Richland 3A Grant 3A Washington 5A Beaver
5A Fayette 5A Ross 3A Greer 3A Washita 5A Bedford
5A Franklin 5A Sandusky 3A Harmon 3A Woods 5A Berks
5A Fulton 4A Scioto 3A Harper 3A Woodward 5A Blair
4A Gallia 5A Seneca 3A Haskell OREGON 5A Bradford
5A Geauga 5A Shelby 3A Hughes 4A Bucks
5A Greene 5A Stark 3A Jackson 5B Baker 5A Butler
5A Guernsey 5A Summit 3A Jefferson 4C Benton 5A Cambria
4A Hamilton 5A Trumbull 3A Johnston 4C Clackamas 6A Cameron
5A Hancock 5A Tuscarawas 3A Kay 4C Clatsop 5A Carbon
5A Hardin 5A Union 3A Kingfisher 4C Columbia 5A Centre
5A Harrison 5A Van Wert 3A Kiowa 4C Coos 4A Chester
5A Henry 5A Vinton 3A Latimer 5B Crook 5A Clarion
5A Highland 5A Warren 3A Le Flore 4C Curry 6A Clearfield
5A Hocking 4A Washington 3A Lincoln 5B Deschutes 5A Clinton
5A Holmes 5A Wayne 3A Logan 4C Douglas 5A Columbia
5A Huron 5A Williams 3A Love 5B Gilliam 5A Crawford
5A Jackson 5A Wood 3A Major 5B Grant 5A Cumberland
5A Jefferson 5A Wyandot 3A Marshall 5B Harney 5A Dauphin
5A Knox OKLAHOMA 3A Mayes 5B Hood River 4A Delaware
5A Lake 3A McClain 4C Jackson 6A Elk
4A Lawrence 3A Adair 3A McCurtain 5B Jefferson 5A Erie
5A Licking 3A Alfalfa 3A McIntosh 4C Josephine 5A Fayette
5A Logan 3A Atoka 3A Murray 5B Klamath 5A Forest
5A Lorain 4B Beaver 3A Muskogee 5B Lake 5A Franklin
5A Lucas 3A Beckham 3A Noble 4C Lane 5A Fulton
5A Madison 3A Blaine 3A Nowata 4C Lincoln 5A Greene
TABLE N1101.10 (R301.1)—continued
5A Huntingdon 3A Bamberg* 5A Bennett 6A Minnehaha 4A Gibson
5A Indiana 3A Barnwell* 5A Bon Homme 6A Moody 4A Giles
5A Jefferson 3A Beaufort* 6A Brookings 6A Pennington 4A Grainger
5A Juniata 3A Berkeley* 6A Brown 6A Perkins 4A Greene
5A Lackawanna 3A Calhoun 6A Brule 6A Potter 4A Grundy
5A Lancaster 3A Charleston* 6A Buffalo 6A Roberts 4A Hamblen
5A Lawrence 3A Cherokee 6A Butte 6A Sanborn 4A Hamilton
5A Lebanon 3A Chester 6A Campbell 6A Shannon 4A Hancock
5A Lehigh 3A Chesterfield 5A Charles Mix 6A Spink 3A Hardeman
5A Luzerne 3A Clarendon 6A Clark 6A Stanley 3A Hardin
5A Lycoming 3A Colleton* 5A Clay 6A Sully 4A Hawkins
6A McKean 3A Darlington 6A Codington 5A Todd 3A Haywood
5A Mercer 3A Dillon 6A Corson 5A Tripp 3A Henderson
5A Mifflin 3A Dorchester* 6A Custer 6A Turner 4A Henry
5A Monroe 3A Edgefield 6A Davison 5A Union 4A Hickman
4A Montgomery 3A Fairfield 6A Day 6A Walworth 4A Houston
5A Montour 3A Florence 6A Deuel 5A Yankton 4A Humphreys
5A Northampton 3A Georgetown* 6A Dewey 6A Ziebach 4A Jackson
5A Northumberland 3A Greenville 5A Douglas TENNESSEE 4A Jefferson
5A Perry 3A Greenwood 6A Edmunds 4A Johnson
4A Philadelphia 3A Hampton* 6A Fall River 4A Anderson 4A Knox
5A Pike 3A Horry* 6A Faulk 4A Bedford 3A Lake
6A Potter 3A Jasper* 6A Grant 4A Benton 3A Lauderdale
5A Schuylkill 3A Kershaw 5A Gregory 4A Bledsoe 4A Lawrence
5A Snyder 3A Lancaster 6A Haakon 4A Blount 4A Lewis
5A Somerset 3A Laurens 6A Hamlin 4A Bradley 4A Lincoln
5A Sullivan 3A Lee 6A Hand 4A Campbell 4A Loudon
6A Susquehanna 3A Lexington 6A Hanson 4A Cannon 4A Macon
6A Tioga 3A Marion 6A Harding 4A Carroll 3A Madison
5A Union 3A Marlboro 6A Hughes 4A Carter 4A Marion
5A Venango 3A McCormick 5A Hutchinson 4A Cheatham 4A Marshall
5A Warren 3A Newberry 6A Hyde 3A Chester 4A Maury
5A Washington 3A Oconee 5A Jackson 4A Claiborne 4A McMinn
6A Wayne 3A Orangeburg 6A Jerauld 4A Clay 3A McNairy
5A Westmoreland 3A Pickens 6A Jones 4A Cocke 4A Meigs
5A Wyoming 3A Richland 6A Kingsbury 4A Coffee 4A Monroe
4A York 3A Saluda 6A Lake 3A Crockett 4A Montgomery
RHODE ISLAND 3A Spartanburg 6A Lawrence 4A Cumberland 4A Moore
3A Sumter 6A Lincoln 4A Davidson 4A Morgan
5A (all) 3A Union 6A Lyman 4A Decatur 4A Obion
3A Williamsburg 6A Marshall 4A DeKalb 4A Overton
3A York 6A McCook 4A Dickson 4A Perry
3A Abbeville SOUTH DAKOTA 6A McPherson 3A Dyer 4A Pickett
3A Aiken 6A Meade 3A Fayette 4A Polk
3A Allendale* 6A Aurora 5A Mellette 4A Fentress 4A Putnam
3A Anderson 6A Beadle 6A Miner 4A Franklin 4A Rhea
TABLE N1101.10 (R301.1)—continued
4A Roane 3B Brewster 3B Ector 3B Howard 3B McCulloch
4A Robertson 4B Briscoe 2B Edwards* 3B Hudspeth 2A McLennan*
4A Rutherford 2A Brooks* 3A Ellis* 3A Hunt* 2A McMullen*
4A Scott 3A Brown* 3B El Paso 4B Hutchinson 2B Medina*
4A Sequatchie 2A Burleson* 3A Erath* 3B Irion 3B Menard
4A Sevier 3A Burnet* 2A Falls* 3A Jack 3B Midland
3A Shelby 2A Caldwell* 3A Fannin 2A Jackson* 2A Milam*
4A Smith 2A Calhoun* 2A Fayette* 2A Jasper* 3A Mills*
4A Stewart 3B Callahan 3B Fisher 3B Jeff Davis 3B Mitchell
4A Sullivan 2A Cameron* 4B Floyd 2A Jefferson* 3A Montague
4A Sumner 3A Camp* 3B Foard 2A Jim Hogg* 2A Montgomery*
3A Tipton 4B Carson 2A Fort Bend* 2A Jim Wells* 4B Moore
4A Trousdale 3A Cass* 3A Franklin* 3A Johnson* 3A Morris*
4A Unicoi 4B Castro 2A Freestone* 3B Jones 3B Motley
4A Union 2A Chambers* 2B Frio* 2A Karnes* 3A Nacogdoches*
4A Van Buren 2A Cherokee* 3B Gaines 3A Kaufman* 3A Navarro*
4A Warren 3B Childress 2A Galveston* 3A Kendall* 2A Newton*
4A Washington 3A Clay 3B Garza 2A Kenedy* 3B Nolan
4A Wayne 4B Cochran 3A Gillespie* 3B Kent 2A Nueces*
4A Weakley 3B Coke 3B Glasscock 3B Kerr 4B Ochiltree
4A White 3B Coleman 2A Goliad* 3B Kimble 4B Oldham
4A Williamson 3A Collin* 2A Gonzales* 3B King 2A Orange*
4A Wilson 3B Collingsworth 4B Gray 2B Kinney* 3A Palo Pinto*
TEXAS 2A Colorado* 3A Grayson 2A Kleberg* 3A Panola*
2A Comal* 3A Gregg* 3B Knox 3A Parker*
2A Anderson* 3A Comanche* 2A Grimes* 3A Lamar* 4B Parmer
3B Andrews 3B Concho 2A Guadalupe* 4B Lamb 3B Pecos
2A Angelina* 3A Cooke 4B Hale 3A Lampasas* 2A Polk*
2A Aransas* 2A Coryell* 3B Hall 2B La Salle* 4B Potter
3A Archer 3B Cottle 3A Hamilton* 2A Lavaca* 3B Presidio
4B Armstrong 3B Crane 4B Hansford 2A Lee* 3A Rains*
2A Atascosa* 3B Crockett 3B Hardeman 2A Leon* 4B Randall
2A Austin* 3B Crosby 2A Hardin* 2A Liberty* 3B Reagan
4B Bailey 3B Culberson 2A Harris* 2A Limestone* 2B Real*
2B Bandera* 4B Dallam 3A Harrison* 4B Lipscomb 3A Red River*
2A Bastrop* 3A Dallas* 4B Hartley 2A Live Oak* 3B Reeves
3B Baylor 3B Dawson 3B Haskell 3A Llano* 2A Refugio*
2A Bee* 4B Deaf Smith 2A Hays* 3B Loving 4B Roberts
2A Bell* 3A Delta 3B Hemphill 3B Lubbock 2A Robertson*
2A Bexar* 3A Denton* 3A Henderson* 3B Lynn 3A Rockwall*
3A Blanco* 2A DeWitt* 2A Hidalgo* 2A Madison* 3B Runnels
3B Borden 3B Dickens 2A Hill* 3A Marion* 3A Rusk*
2A Bosque* 2B Dimmit* 4B Hockley 3B Martin 3A Sabine*
3A Bowie* 4B Donley 3A Hood* 3B Mason 3A San Augustine*
2A Brazoria* 2A Duval* 3A Hopkins* 2A Matagorda* 2A San Jacinto*
2A Brazos* 3A Eastland 2A Houston* 2B Maverick* 2A San Patricio*
TABLE N1101.10 (R301.1)—continued
3A San Saba* 3A Young 4C Clark 4A Gilmer WISCONSIN
3B Schleicher 2B Zapata* 5B Columbia 5A Grant 6A Adams
3B Scurry 2B Zavala* 4C Cowlitz 5A Greenbrier 7 Ashland
3B Shackelford UTAH 5B Douglas 5A Hampshire 6A Barron
3A Shelby* 6B Ferry 5A Hancock 7 Bayfield
4B Sherman 5B Beaver 5B Franklin 5A Hardy 6A Brown
3A Smith* 6B Box Elder 5B Garfield 5A Harrison 6A Buffalo
3A Somervell* 6B Cache 5B Grant 4A Jackson 7 Burnett
2A Starr* 6B Carbon 4C Grays Harbor 4A Jefferson 6A Calumet
3A Stephens 6B Daggett 4C Island 4A Kanawha 6A Chippewa
3B Sterling 5B Davis 4C Jefferson 5A Lewis 6A Clark
3B Stonewall 6B Duchesne 4C King 4A Lincoln 6A Columbia
3B Sutton 5B Emery 4C Kitsap 4A Logan 6A Crawford
4B Swisher 5B Garfield 5B Kittitas 5A Marion 6A Dane
3A Tarrant* 5B Grand 5B Klickitat 5A Marshall 6A Dodge
3B Taylor 5B Iron 4C Lewis 4A Mason 6A Door
3B Terrell 5B Juab 5B Lincoln 4A McDowell 7 Douglas
3B Terry 5B Kane 4C Mason 4A Mercer 6A Dunn
3B Throckmorton 5B Millard 6B Okanogan 5A Mineral 6A Eau Claire
3A Titus* 6B Morgan 4C Pacific 4A Mingo 7 Florence
3B Tom Green 5B Piute 6B Pend Oreille 5A Monongalia 6A Fond du Lac
2A Travis* 6B Rich 4C Pierce 4A Monroe 7 Forest
2A Trinity* 5B Salt Lake 4C San Juan 4A Morgan 6A Grant
2A Tyler* 5B San Juan 4C Skagit 5A Nicholas 6A Green
3A Upshur* 5B Sanpete 5B Skamania 5A Ohio 6A Green Lake
3B Upton 5B Sevier 4C Snohomish 5A Pendleton 6A Iowa
2B Uvalde* 6B Summit 5B Spokane 4A Pleasants 7 Iron
2B Val Verde* 5B Tooele 6B Stevens 5A Pocahontas 6A Jackson
3A Van Zandt* 6B Uintah 4C Thurston 5A Preston 6A Jefferson
2A Victoria* 5B Utah 4C Wahkiakum 4A Putnam 6A Juneau
2A Walker* 6B Wasatch 5B Walla Walla 5A Raleigh 6A Kenosha
2A Waller* 3B Washington 4C Whatcom 5A Randolph 6A Kewaunee
3B Ward 5B Wayne 5B Whitman 4A Ritchie 6A La Crosse
2A Washington* 5B Weber 5B Yakima 4A Roane 6A Lafayette
2B Webb* VERMONT WEST VIRGINIA 5A Summers 7 Langlade
2A Wharton* 5A Taylor 7 Lincoln
3B Wheeler 6A (all) 5A Barbour 5A Tucker 6A Manitowoc
3A Wichita VIRGINIA 4A Berkeley 4A Tyler 6A Marathon
3B Wilbarger 4A Boone 5A Upshur 6A Marinette
2A Willacy* 4A (all) 4A Braxton 4A Wayne 6A Marquette
2A Williamson* WASHINGTON 5A Brooke 5A Webster 6A Menominee
2A Wilson* 4A Cabell 5A Wetzel 6A Milwaukee
3B Winkler 5B Adams 4A Calhoun 4A Wirt 6A Monroe
3A Wise 5B Asotin 4A Clay 4A Wood 6A Oconto
3A Wood* 5B Benton 5A Doddridge 4A Wyoming 7 Oneida
4B Yoakum 5B Chelan 5A Fayette   6A Outagamie
  4C Clallam      
TABLE N1101.10 (R301.1)—continued
6A Ozaukee 7 Taylor 6B Big Horn 6B Sheridan NORTHERN
6A Pepin 6A Trempealeau 6B Campbell 7 Sublette
6A Pierce 6A Vernon 6B Carbon 6B Sweetwater
6A Polk 7 Vilas 6B Converse 7 Teton 1A (all)*
6A Portage 6A Walworth 6B Crook 6B Uinta PUERTO RICO
7 Price 7 Washburn 6B Fremont 6B Washakie
6A Racine 6A Washington 5B Goshen 6B Weston 1A (all)*
6A Richland 6A Waukesha 6B Hot Springs US TERRITORIES VIRGIN ISLANDS
6A Rock 6A Waupaca 6B Johnson
6A Rusk 6A Waushara 6B Laramie AMERICAN
1A (all)*
6A Sauk 6A Winnebago 7 Lincoln
7 Sawyer 6A Wood 6B Natrona 1A (all)*
6A Shawano WYOMING 6B Niobrara GUAM
6A Sheboygan 6B Park
6A St. Croix 6B Albany 5B Platte 1A (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)]
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]
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)]
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)]
Single Double
Metal 1.20 0.80 2.00 1.30
Metal with Thermal Break 1.10 0.65 1.90 1.10
Nonmetal or Metal Clad 0.95 0.55 1.75 1.05
Glazed Block 0.60
TABLE N1101.12.3(2) [R303.1.3(2)]
Uninsulated Metal 1.20
Insulated Metal 0.60
Wood 0.50
Insulated, nonmetal edge, max 45% glazing, any glazing double pane 0.35
TABLE N1101.12.3(3) [R303.1.3(3)]
Clear Tinted Clear Tinted
SHGC 0.8 0.7 0.7 0.6 0.6
VT 0.6 0.3 0.6 0.3 0.6
The thermal resistance (R-value) of insulation shall be determined in accordance with the U.S. Federal Trade Commission R-value rule (CFR Title 16, Part 460) in units of h × ft2 × °F/Btu at a mean temperature of 75°F (24°C).
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)
SHGCb, e
1 NR 0.75 0.25 30 13 3/4 13 0 0 0
2 0.40 0.65 0.25 38 13 4/6 13 0 0 0
3 0.35 0.55 0.25 38 20 or 13 + 5h 8/13 19 5/13f 0 5/13
4 except Marine 0.35 0.55 0.40 49 20 or 13 + 5h 8/13 19 10 /13 10, 2 ft 10/13
5 and Marine 4 0.32 0.55 NR 49 20 or 13 + 5h 13/17 30g 15/19 10, 2 ft 15/19
6 0.32 0.55 NR 49 20 + 5 or 13 + 10h 15/20 30g 15/19 10, 4 ft 15/19
7 and 8 0.32 0.55 NR 49 20 + 5 or 13 + 10h 19/21 38g 15/19 10, 4 ft 15/19
For SI: 1 foot = 304.8 mm.
  1. R-values are minimums. U-factors and SHGC are maximums. When insulation is installed in a cavity which is less than the label or design thickness of the insulation, the installed R-value of the insulation shall not be less than the R-value specified in the table.
  2. The fenestration U-factor column excludes skylights. The SHGC column applies to all glazed fenestration.
    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.
  3. "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.
  4. 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.
  5. There are no SHGC requirements in the Marine Zone.
  6. Basement wall insulation is not required in warm-humid locations as defined by Figure N1101.10 and Table N1101.10.
  7. Or insulation sufficient to fill the framing cavity, R-19 minimum.
  8. 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.
  9. 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)
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
7 and 80.320.550.0260.0480.0570.0280.0500.055
  1. Nonfenestration U-factors shall be obtained from measurement, calculation or an approved source.
  2. When more than half the insulation is on the interior, the mass wall U-factors shall be a maximum of 0.17 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.
  3. 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 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 + 3 R-0 + 11.2 or R-13 + 6.1 or R-15 + 5.7 or
R-19 + 5.0 or R-21 + 4.7
R-20 R-0 + 14.0 or R-13 + 8.9 or R-15 + 8.5 or
R-19 + 7.8 or R-19 + 6.2 or R-21 + 7.5
R-20 + 5 R-13 + 12.7 or R-15 + 12.3 or R-19 + 11.6 or
R-21 + 11.3 or R-25 + 10.9
R-21 R-0 + 14.6 or R-13 + 9.5 or R-15 + 9.1 or
R-19 + 8.4 or R-21 + 8.1 or R-25 + 7.7
Steel-Framed Wall, 24" o.c.
R-13 R-0 + 9.3 or R-13 + 3.0 or R-15 + 2.4
R-13 + 3 R-0 + 11.2 or R-13 + 4.9 or R-15 + 4.3 or
R-19 + 3.5 or R-21 + 3.1
R-20 R-0 + 14.0 or R-13 + 7.7 or R-15 + 7.1 or
R-19 + 6.3 or R-21 + 5.9
R-20 + 5 R-13 + 11.5 or R-15 + 10.9 or R-19 + 10.1 or
R-21 + 9.7 or R-25 + 9.1
R-21 R-0 + 14.6 or R-13 + 8.3 or R-15 + 7.7 or
R-19 + 6.9 or R-21 + 6.5 or R-25 + 5.9
Steel Joist Floor
R-13 R-19 in 2 × 6, or R-19 + 6 in 2 × 8 or 2 × 10
R-19 R-19 + 6 in 2 × 6, or R-19 + 12 in 2 × 8 or 2 × 10
  1. Cavity insulation R-value is listed first, followed by continuous insulation R-value.
  2. Insulation exceeding the height of the framing shall cover the framing.
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 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.
(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.
  1. 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.
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.
  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)
Nominal pipe diameter of largest
diameter pipe in the run (inch)
3/8 1/2 3/4 > 3/4
Maximum run length 30 20 10 5
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm.
  1. 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.
Mechanical ventilation system fans shall meet the efficacy requirements of Table N1103.5.1.
Exception: Where 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)
Range hoods Any 2.8 cfm/watt Any
In-line fan Any 2.8 cfm/watt Any
Bathroom, utility room 10 1.4 cfm/watt < 90
Bathroom, utility room 90 2.8 cfm/watt Any
For SI: 1 cubic foot per minute = 28.3 L/min.
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.
  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)]
Above-grade walls Type: mass wall if proposed wall is mass; otherwise wood frame. As proposed
Gross area: same as proposed As proposed
U-factor: from Table N1102.1.3 As proposed
Solar absorptance = 0.75 As proposed
Remittance = 0.90 As proposed
Basement and crawl space walls Type: same as proposed As proposed
Gross area: same as proposed As proposed
U-factor: from Table N1102.1.3, with insulation layer on interior side of walls. As proposed
Above-grade floors Type: wood frame As proposed
Gross area: same as proposed As proposed
U-factor: from Table N1102.1.3 As proposed
Ceilings Type: wood frame As proposed
Gross area: same as proposed As proposed
U-factor: from Table N1102.1.3 As proposed
Roofs Type: composition shingle on wood sheathing As proposed
Gross area: same as proposed As proposed
Solar absorptance = 0.75 As proposed
Emittance = 0.90 As proposed
Attics Type: vented with aperture = 1 ft2 per 300 ft2 ceiling area As proposed
Foundations Type: same as proposed foundation wall area above and below grade and soil characteristics: same as proposed. As proposed
As proposed
Doors Area: 40 ft2 As proposed
Orientation: North As proposed
U-factor: same as fenestration from Table N1102.1.3. As proposed
Glazinga Total areab =
  1. The proposed glazing area; where proposed glazing area is less than 15% of the conditioned floor area.
  2. 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.
As proposed
Interior shade fraction: 0.92-(0.21 × SHGC for the standard reference design) 0.92-(0.21 × SHGC as proposed)
External shading: none As proposed
Skylights None As proposed
Thermally isolated sunrooms None As proposed
Air exchange rate Air leakage rate of 5 air changes per hour in 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)
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)
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. As proposed
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. As proposed
For other walls, for ceilings, floors, and interior walls, wood frame construction. 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 As proposed
Use: same as proposed design gal/day = 30 + (10 × Nbr)
Thermal distribution systems None Thermal 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.
  1. 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.
  2. 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


    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.
  3. 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.
  4. 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.
  5. 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.
  6. 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.
  7. 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.
  8. 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.
  9. 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)] 
Distribution system components located in unconditioned space 0.95
Untested distribution systems entirely located in conditioned spacec 0.88 1
"Ductless" systemsd 1

For SI: 1 cubic foot per minute = 0.47 L/s, 1 square foot = 0.093m2, 1 pound per square inch = 6895 Pa, 1 inch water gauge = 1250 Pa.
  1. Default values given by this table are for untested distribution systems, which must still meet minimum requirements for duct system insulation.
  2. 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.
  3. 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.
  4. 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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