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/h•ft2 (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”).
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)
CLIMATE ZONES
TABLE N1101.10 (R301.1)
CLIMATE ZONES, MOISTURE REGIMES, AND WARM-HUMID
DESIGNATIONS BY STATE, COUNTY AND TERRITORY
Key: A – Moist, B – Dry, C – Marine. Absence of moisture designation indicates moisture regime is irrelevant.
Asterisk (*) indicates a warm-humid location.
US STATES
| 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 | |||||
(continued)
TABLE N1101.10 (R301.1)—continued
CLIMATE ZONES, MOISTURE REGIMES, AND WARM-HUMID
DESIGNATIONS BY STATE, COUNTY AND TERRITORY
| 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 COLUMBIA | 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 | |
(continued)
TABLE N1101.10 (R301.1)—continued
CLIMATE ZONES, MOISTURE REGIMES, AND WARM-HUMID
DESIGNATIONS BY STATE, COUNTY AND TERRITORY
| 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 | |
(continued)
TABLE N1101.10 (R301.1)—continued
CLIMATE ZONES, MOISTURE REGIMES, AND WARM-HUMID
DESIGNATIONS BY STATE, COUNTY AND TERRITORY
| 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 | |
(continued)
TABLE N1101.10 (R301.1)—continued
CLIMATE ZONES, MOISTURE REGIMES, AND WARM-HUMID
DESIGNATIONS BY STATE, COUNTY AND TERRITORY
| 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 | ||
(continued)
TABLE N1101.10 (R301.1)—continued
CLIMATE ZONES, MOISTURE REGIMES, AND WARM-HUMID
DESIGNATIONS BY STATE, COUNTY AND TERRITORY
| 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 | ||
(continued)
TABLE N1101.10 (R301.1)—continued
CLIMATE ZONES, MOISTURE REGIMES, AND WARM-HUMID
DESIGNATIONS BY STATE, COUNTY AND TERRITORY
| 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 HAMPSHIRE | 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 | |||
(continued)
TABLE N1101.10 (R301.1)—continued
CLIMATE ZONES, MOISTURE REGIMES, AND WARM-HUMID
DESIGNATIONS BY STATE, COUNTY AND TERRITORY
| 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 CAROLINA | 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 | ||
(continued)
TABLE N1101.10 (R301.1)—continued
CLIMATE ZONES, MOISTURE REGIMES, AND WARM-HUMID
DESIGNATIONS BY STATE, COUNTY AND TERRITORY
| 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 | |
(continued)
TABLE N1101.10 (R301.1)—continued
CLIMATE ZONES, MOISTURE REGIMES, AND WARM-HUMID
DESIGNATIONS BY STATE, COUNTY AND TERRITORY
| 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 | |
| SOUTH CAROLINA | 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 | |
(continued)
TABLE N1101.10 (R301.1)—continued
CLIMATE ZONES, MOISTURE REGIMES, AND WARM-HUMID
DESIGNATIONS BY STATE, COUNTY AND TERRITORY
| 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* | |
(continued)
TABLE N1101.10 (R301.1)—continued
CLIMATE ZONES, MOISTURE REGIMES, AND WARM-HUMID
DESIGNATIONS BY STATE, COUNTY AND TERRITORY
| 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 | |||||
(continued)
TABLE N1101.10 (R301.1)—continued
CLIMATE ZONES, MOISTURE REGIMES, AND WARM-HUMID
DESIGNATIONS BY STATE, COUNTY AND TERRITORY
| 6A Ozaukee | 7 Taylor | 6B Big Horn | 6B Sheridan | NORTHERN MARIANA ISLANDS | |
| 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 SAMOA | 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)]
INTERNATIONAL CLIMATE ZONE DEFINITIONS
| MAJOR CLIMATE TYPE DEFINITIONS |
| Marine (C) Definition—Locations meeting all four criteria: 1. Mean temperature of coldest month between -3°C (27°F) and 18°C (65°F). 2. Warmest month mean < 22°C (72°F). 3. At least four months with mean temperatures over 10°C (50°F). 4. Dry season in summer. The month with the heaviest precipitation in the cold season has at least three times as much precipitation as the month with the least precipitation in the rest of the year. The cold season is October through March in the Northern Hemisphere and April through September in the Southern Hemisphere. |
| Dry (B) Definition—Locations meeting the following criteria: Not marine and Pin < 0.44 × (TF - 19.5) [Pcm < 2.0 × (TC + 7) in SI units] where: Pin = Annual precipitation in inches (cm) T = Annual mean temperature in °F (°C) |
| Moist (A) Definition—Locations that are not marine and not dry. |
| Warm-humid Definition—Moist (A) locations where either of the following wet-bulb temperature conditions shall occur during the warmest six consecutive months of the year: 1. 67°F (19.4°C) or higher for 3,000 or more hours; or 2. 73°F (22.8°C) or higher for 1,500 or more hours. |
For SI: °C = [(°F)-32]/1.8, 1 inch = 2.54 cm.
TABLE N1101.10.2(2) [R301.3(2)]
INTERNATIONAL CLIMATE ZONE DEFINITIONS
| ZONE NUMBER | THERMAL CRITERIA | |
| IP Units | SI Units | |
| 1 | 9000 < CDD50°F | 5000 < CDD10°C |
| 2 | 6300 < CDD50°F ≤ 9000 | 3500 < CDD10°C ≤ 5000 |
| 3A and 3B | 4500 < CDD50°F ≤ 6300 AND HDD65°F ≤ 5400 | 2500 < CDD10°C ≤ 3500 AND HDD18°C ≤ 3000 |
| 4A and 4B | CDD50°F ≤ 4500 AND HDD65°F ≤ 5400 | CDD10°C ≤ 2500 AND HDD18°C ≤ 3000 |
| 3C | HDD65°F ≤ 3600 | HDD18°C ≤ 2000 |
| 4C | 3600 < HDD65°F ≤ 5400 | 2000 < HDD18°C ≤ 3000 |
| 5 | 5400 < HDD65°F ≤ 7200 | 3000 < HDD18°C ≤ 4000 |
| 6 | 7200 < HDD65°F ≤ 9000 | 4000 < HDD18°C ≤ 5000 |
| 7 | 9000 < HDD65°F ≤ 12600 | 5000 < HDD18°C ≤ 7000 |
| 8 | 12600 < HDD65°F | 7000 < HDD18°C |
For SI: °C = [(°F)-32]/1.8.
The interior design temperatures used for heating and cooling load calculations shall be a maximum of 72°F (22°C) for heating and minimum of 75°F (24°C) for cooling.
Materials, systems and equipment shall be identified in a manner that will allow a determination of compliance with the applicable provisions of this code.
An R-value identification mark shall be applied by the manufacturer to each piece of building thermal envelope insulation 12 inches (305 mm) or greater in width. Alternately, the insulation installers shall provide a certification listing the type, manufacturer and R-value of insulation installed in each element of the building thermal envelope. For blown or sprayed insulation (fiberglass and cellulose), the initial installed thickness, settled thickness, settled R-value, installed density, coverage area and number of bags installed shall be listed on the certification. For sprayed polyurethane foam (SPF) insulation, the installed thickness of the areas covered and R-value of installed thickness shall be listed on the certification. The insulation installer shall sign, date and post the certification in a conspicuous location on the job site.
The thickness of blown-in or sprayed roof/ceiling insulation (fiberglass or cellulose) shall be written in inches (mm) on markers that are installed at least one for every 300 square feet (28 m2) throughout the attic space. The markers shall be affixed to the trusses or joists and marked with the minimum initial installed thickness with numbers a minimum of 1 inch (25 mm) in height. Each marker shall face the attic access opening. Spray polyurethane foam thickness and installed R-value shall be listed on certification provided by the insulation installer.
Insulating materials shall be installed such that the manufacturer's R-value mark is readily observable upon inspection.
U-factors of fenestration products (windows, doors and skylights) shall be determined in accordance with NFRC 100 by an accredited, independent laboratory, and labeled and certified by the manufacturer. Products lacking such a labeled U-factor shall be assigned a default U-factor from Table N1101.12.3(1) or N1101.12.3(2). The solar heat gain coefficient (SHGC) and visible transmittance (VT) of glazed fenestration products (windows, glazed doors and skylights) shall be determined in accordance with NFRC 200 by an accredited, independent laboratory, and labeled and certified by the manufacturer. Products lacking such a labeled SHGC or VT shall be assigned a default SHGC or VT from Table N1101.12.3(3).
TABLE N1101.12.3(1) [R303.1.3(1)]
DEFAULT GLAZED FENESTRATION U-FACTOR
| FRAME TYPE | SINGLE PANE | DOUBLE PANE | SKYLIGHT | |
| 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)]
DEFAULT DOOR U-FACTORS
| DOOR TYPE | U-FACTOR |
| Uninsulated Metal | 1.20 |
| Insulated Metal | 0.60 |
| Wood | 0.50 |
| Insulated, nonmetal edge, max 45% glazing, any glazing double pane | 0.35 |
TABLE N1101.12.3(3) [R303.1.3(3)]
DEFAULT GLAZED FENESTRATION SHGC AND VT
| SINGLE GLAZED | DOUBLE GLAZED | GLAZED BLOCK | |||
| Clear | Tinted | Clear | Tinted | ||
| SHGC | 0.8 | 0.7 | 0.7 | 0.6 | 0.6 |
| VT | 0.6 | 0.3 | 0.6 | 0.3 | 0.6 |
The thermal resistance (R-value) of insulation shall be determined in accordance with the U.S. Federal Trade Commission R-value rule (CFR Title 16, Part 460) in units of h × ft2 × °F/Btu at a mean temperature of 75°F (24°C).
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 Table N1102.1.1 based on the climate zone specified in Section N1101.10.
TABLE N1102.1.1 (R402.1.1)
INSULATION AND FENESTRATION REQUIREMENTS BY COMPONENTa
| CLIMATE ZONE | FENESTRATION U-FACTORb | SKYLIGHTb U-FACTOR | GLAZED FENESTRATION SHGCb, e | CEILING R-VALUE | WOOD FRAME WALL R-VALUE | MASS WALL R-VALUEi | FLOOR R-VALUE | BASEMENTc WALL R-VALUE | SLABd R-VALUE & DEPTH | CRAWL SPACEc WALL R-VALUE |
| 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.
a. R-values are minimums. U-factors and SHGC are maximums. When insulation is installed in a cavity which is less than the label or design thickness of the insulation, the installed R-value of the insulation shall not be less than the R-value specified in the table.
b. The fenestration U-factor column excludes skylights. The SHGC column applies to all glazed fenestration.
Exception: Skylights may be excluded from glazed fenestration SHGC requirements in Climate Zones 1 through 3 where the SHGC for such skylights does not exceed 0.30.
c. “15/19” means R-15 continuous insulation on the interior or exterior of the home or R-19 cavity insulation at the interior of the basement wall. “15/19” shall be permitted to be met with R-13 cavity insulation on the interior of the basement wall plus R-5 continuous insulation on the interior or exterior of the home. “10/13” means R-10 continuous insulation on the interior or exterior of the home or R-13 cavity insulation at the interior of the basement wall.
d. R-5 shall be added to the required slab edge R-values for heated slabs. Insulation depth shall be the depth of the footing or 2 feet, whichever is less in Zones 1 through 3 for heated slabs.
e. There are no SHGC requirements in the Marine Zone.
f. Basement wall insulation is not required in warm-humid locations as defined by Figure N1101.10 and Table N1101.10.
g. Or insulation sufficient to fill the framing cavity, R-19 minimum.
h. First value is cavity insulation, second is continuous insulation or insulated siding, so “13 + 5” means R-13 cavity insulation plus R-5 continuous insulation or insulated siding. If structural sheathing covers 40 percent or less of the exterior, continuous insulation R-value shall be permitted to be reduced by no more than R-3 in the locations where structural sheathing is used – to maintain a consistent total sheathing thickness.
i. The second R-value applies when more than half the insulation is on the interior of the mass wall.
Insulation material used in layers, such as framing cavity insulation and insulating sheathing, shall be summed to compute the component R-value. The manufacturer's settled R-value shall be used for blown insulation. Computed R-values shall not include an R-value for other building materials or air films.
An assembly with a U-factor equal to or less than that specified in Table N1102.1.3 shall be permitted as an alternative to the R-value in Table N1102.1.1.
TABLE N1102.1.3 (R402.1.3)
EQUIVALENT U-FACTORSa
| CLIMATE ZONE | FENESTRATION U-FACTOR | SKYLIGHT U-FACTOR | CEILING U-FACTOR | FRAME WALL U-FACTOR | MASS WALL U-FACTORb | FLOOR U-FACTOR | BASEMENT WALL U-FACTOR | CRAWL SPACE WALL U-FACTOR |
| 1 | 0.50 | 0.75 | 0.035 | 0.082 | 0.197 | 0.064 | 0.360 | 0.477 |
| 2 | 0.40 | 0.65 | 0.030 | 0.082 | 0.165 | 0.064 | 0.360 | 0.477 |
| 3 | 0.35 | 0.55 | 0.030 | 0.057 | 0.098 | 0.047 | 0.091c | 0.136 |
| 4 except Marine | 0.35 | 0.55 | 0.026 | 0.057 | 0.098 | 0.047 | 0.059 | 0.065 |
| 5 and Marine 4 | 0.32 | 0.55 | 0.026 | 0.057 | 0.082 | 0.033 | 0.050 | 0.055 |
| 6 | 0.32 | 0.55 | 0.026 | 0.048 | 0.060 | 0.033 | 0.050 | 0.055 |
| 7 and 8 | 0.32 | 0.55 | 0.026 | 0.048 | 0.057 | 0.028 | 0.050 | 0.055 |
a. Nonfenestration U-factors shall be obtained from measurement, calculation or an approved source.
b. When more than half the insulation is on the interior, the mass wall U-factors shall be a maximum of 0.17 in Zone 1, 0.14 in Zone 2, 0.12 in Zone 3, 0.087 in Zone 4 except Marine, 0.065 in Zone 5 and Marine 4, and 0.057 in Zones 6 through 8.
c. Basement wall U-factor of 0.360 in warm-humid locations as defined by Figure N1101.10 (R301.1) and Table N1101.10 (R301.1).
If the total building thermal envelope UA (sum of U-factor times assembly area) is less than or equal to the total UA resulting from using the U-factors in Table N1102.1.3 (multiplied by the same assembly area as in the proposed building), the building shall be considered in compliance with Table N1102.1.1. The UA calculation shall be done using a method consistent with the ASHRAE Handbook of Fundamentals and shall include the thermal bridging effects of framing materials. The SHGC requirements shall be met in addition to UA compliance.
In addition to the requirements of Section N1102.1, insulation shall meet the specific requirements of Sections N1102.2.1 through N1102.2.12.
When Section N1102.1.1 would require R-38 in the ceiling, R-30 shall be deemed to satisfy the requirement for R-38 wherever the full height of uncompressed R-30 insulation extends over the wall top plate at the eaves. Similarly, R-38 shall be deemed to satisfy the requirement for R-49 wherever the full height of uncompressed R-38 insulation extends over the wall top plate at the eaves. This reduction shall not apply to the U-factor alternative approach in Section N1102.1.3 and the total UA alternative in Section N1102.1.4.
Where Section N1102.1.1 would require insulation levels above R-30 and the design of the roof/ceiling assembly does not allow sufficient space for the required insulation, the minimum required insulation for such roof/ceiling assemblies shall be R-30. This reduction of insulation from the requirements of Section N1102.1.1 shall be limited to 500 square feet (46 m2) or 20 percent of the total insulated ceiling area, whichever is less. This reduction shall not apply to the U-factor alternative approach in Section N1102.1.3 and the total UA alternative in Section N1102.1.4.
For air permeable insulations in vented attics, a baffle shall be installed adjacent to soffit and eave vents. Baffles shall maintain an opening equal or greater than the size of the vent. The baffle shall extend over the top of the attic insulation. The baffle shall be permitted to be any solid material.
Access doors from conditioned spaces to unconditioned spaces (e.g., attics and crawl spaces) shall be weatherstripped and insulated to a level equivalent to the insulation on the surrounding surfaces. Access shall be provided to all equipment that prevents damaging or compressing the insulation. A wood framed or equivalent baffle or retainer is required to be provided when loose fill insulation is installed, the purpose of which is to prevent the loose fill insulation from spilling into the living space when the attic access is opened, and to provide a permanent means of maintaining the installed R-value of the loose fill insulation.
Steel-frame ceilings, walls, and floors shall meet the insulation requirements of Table N1102.2.6 or shall meet the U-factor requirements of Table N1102.1.3. The calculation of the U-factor for a steel-frame envelope assembly shall use a series-parallel path calculation method.
TABLE N1102.2.6 (R402.2.6)
STEEL-FRAME CEILING, WALL AND FLOOR INSULATION
(R-VALUE)
| WOOD FRAME R-VALUE REQUIREMENT | COLD-FORMED STEEL EQUIVALENT R-VALUEa |
| Steel Truss Ceilingsb | |
| R-30 | R-38 or R-30 + 3 or R-26 + 5 |
| R-38 | R-49 or R-38 + 3 |
| R-49 | R-38 + 5 |
| Steel Joist Ceilingsb | |
| R-30 | R-38 in 2 × 4 or 2 × 6 or 2 × 8 R-49 in any framing |
| R-38 | R-49 in 2 × 4 or 2 × 6 or 2 × 8 or 2 × 10 |
| Steel-Framed Wall, 16″ o.c. | |
| R-13 | R-13 + 4.2 or R-19 + 2.1 or R-21 + 2.8 or R-0 + 9.3 or R-15 + 3.8 or R-21 + 3.1 |
| R-13 + 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 |
a. Cavity insulation R-value is listed first, followed by continuous insulation R-value.
b. Insulation exceeding the height of the framing shall cover the framing.
Floor insulation shall be installed to maintain permanent contact with the underside of the subfloor decking.
Walls associated with conditioned basements shall be insulated from the top of the basement wall down to 10 feet (3048 mm) below grade or to the basement floor, whichever is less. Walls associated with unconditioned basements shall meet this requirement unless the floor overhead is insulated in accordance with Sections N1102.1.1 and N1102.2.7.
Slab-on-grade floors with a floor surface less than 12 inches (305 mm) below grade shall be insulated in accordance with Table N1102.1.1. The insulation shall extend downward from the top of the slab on the outside or inside of the foundation wall. Insulation located below grade shall be extended the distance provided in Table N1102.1.1 by any combination of vertical insulation, insulation extending under the slab or insulation extending out from the building. Insulation extending away from the building shall be protected by pavement or by a minimum of 10 inches (254 mm) of soil. The top edge of the insulation installed between the exterior wall and the edge of the interior slab shall be permitted to be cut at a 45-degree (0.79 rad) angle away from the exterior wall. Slab-edge insulation is not required in jurisdictions designated by the building official as having a very heavy termite infestation.
As an alternative to insulating floors over crawl spaces, crawl space walls shall be permitted to be insulated when the crawl space is not vented to the outside. Crawl space wall insulation shall be permanently fastened to the wall and extend downward from the floor to the finished grade level and then vertically and/or horizontally for at least an additional 24 inches (610 mm). Exposed earth in unvented crawl space foundations shall be covered with a continuous Class I vapor retarder in accordance with this code. All joints of the vapor retarder shall overlap by 6 inches (153 mm) and be sealed or taped. The edges of the vapor retarder shall extend at least 6 inches (153 mm) up the stem wall and shall be attached to the stem wall.
Insulation shall not be required on the horizontal portion of the foundation that supports a masonry veneer.
All sunrooms enclosing conditioned spaces shall meet the insulation requirements of this code.
Exception: For sunrooms with thermal isolation, and enclosing conditioned spaces, the following exceptions to the insulation requirements of this code shall apply:
1. The minimum ceiling insulation R-values shall be R-19 in Zones 1 through 4 and R-24 in Zones 5 through 8; and
2. The minimum wall R-value shall be R-13 in all zones. Wall(s) separating a sunroom with a thermal isolation from conditioned space shall meet the building thermal envelope requirements of this code.
In addition to the requirements of Section N1102, fenestration shall comply with Sections N1102.3.1 through N1102.3.6.
An area-weighted average of fenestration products shall be permitted to satisfy the U-factor requirements.
An area-weighted average of fenestration products more than 50-percent glazed shall be permitted to satisfy the SHGC requirements.
Up to 15 square feet (1.4 m2) of glazed fenestration per dwelling unit shall be permitted to be exempt from U-factor and SHGC requirements in Section N1102.1.1. This exemption shall not apply to the U-factor alternative approach in Section N1102.1.3 and the Total UA alternative in Section N1102.1.4.
One side-hinged opaque door assembly up to 24 square feet (2.22 m2) in area is exempted from the U-factor requirement in Section N1102.1.1. This exemption shall not apply to the U-factor alternative approach in Section N1102.1.3 and the total UA alternative in Section N1102.1.4.
All sunrooms enclosing conditioned spaces shall meet the fenestration requirements of this code.
Exception: For sunrooms with thermal isolation and enclosing conditioned spaces, in Zones 4 through 8, the following exceptions to the fenestration requirements of this code shall apply:
1. The maximum fenestration U-factor shall be 0.45; and
2. The maximum skylight U-factor shall be 0.70. New fenestration separating the sunroom with thermal isolation from conditioned space shall meet the building thermal envelope requirements of this code.
Where some or all of an existing fenestration unit is replaced with a new fenestration product, including sash and glazing, the replacement fenestration unit shall meet the applicable requirements for U-factor and SHGC in Table N1102.1.1.
The building thermal envelope shall be constructed to limit air leakage in accordance with the requirements of Sections N1102.4.1 through N1102.4.4.
The building thermal envelope shall comply with Sections N1102.4.1.1 and N1102.4.1.2. The sealing methods between dissimilar materials shall allow for differential expansion and contraction.
The components of the building thermal envelope as listed in Table N1102.4.1.1 shall be installed in accordance with the manufacturer's instructions and the criteria listed in Table N1102.4.1.1, as applicable to the method of construction. Where required by the building official, an approved third party shall inspect all components and verify compliance.
TABLE N1102.4.1.1 (R402.4.1.1)
AIR BARRIER AND INSULATION INSTALLATION
| COMPONENT | CRITERIAa |
| Air barrier and thermal barrier | A continuous air barrier shall be installed in the building envelope. Exterior thermal envelope contains a continuous air barrier. Breaks or joints in the air barrier shall be sealed. Air-permeable insulation shall not be used as a sealing material. |
| Ceiling/attic | The air barrier in any dropped ceiling/soffit shall be aligned with the insulation and any gaps in the air barrier sealed. Access openings, drop down stair or knee wall doors to unconditioned attic spaces shall be sealed. |
| Walls | Corners and headers shall be insulated and the junction of the foundation and sill plate shall be sealed. The junction of the top plate and top of exterior walls shall be sealed. Exterior thermal envelope insulation for framed walls shall be installed in substantial contact and continuous alignment with the air barrier. Knee walls shall be sealed. |
| Windows, skylights and doors | The space between window/door jambs and framing and skylights and framing shall be sealed. |
| Rim joists | Rim joists shall be insulated and include the air barrier. |
| Floors (including above-garage and cantilevered floors) | Insulation shall be installed to maintain permanent contact with underside of subfloor decking. The air barrier shall be installed at any exposed edge of insulation. |
| Crawl space walls | Where provided in lieu of floor insulation, insulation shall be permanently attached to the crawlspace walls. Exposed earth in unvented crawl spaces shall be covered with a Class I vapor retarder with overlapping joints taped. |
| Shafts, penetrations | Duct shafts, utility penetrations, and flue shafts opening to exterior or unconditioned space shall be sealed. |
| Narrow cavities | Batts in narrow cavities shall be cut to fit, or narrow cavities shall be filled by insulation that on installation readily conforms to the available cavity space. |
| Garage separation | Air sealing shall be provided between the garage and conditioned spaces. |
| Recessed lighting | Recessed light fixtures installed in the building thermal envelope shall be air tight, IC rated, and sealed to the drywall. |
| Plumbing and wiring | Batt insulation shall be cut neatly to fit around wiring and plumbing in exterior walls, or insulation that on installation readily conforms to available space shall extend behind piping and wiring. |
| Shower/tub on exterior wall | Exterior walls adjacent to showers and tubs shall be insulated and the air barrier installed separating them from the showers and tubs. |
| Electrical/phone box on exterior walls | The air barrier shall be installed behind electrical or communication boxes or air-sealed boxes shall be installed. |
| HVAC register boots | HVAC register boots that penetrate building thermal envelope shall be sealed to the subfloor or drywall. |
| Fireplace | An air barrier shall be installed on fireplace walls. Fireplaces shall have gasketed doors. |
a. In addition, inspection of log walls shall be in accordance with the provisions of ICC-400.
The building or dwelling unit shall be tested and verified as having an air leakage rate of not exceeding 5 air changes per hour in Zones 1 and 2, and 3 air changes per hour in Zones 3 through 8. Testing shall be conducted with a blower door at a pressure of 0.2 inches w.g. (50 Pascals). Where required by the building official, testing shall be conducted by an approved third party. A written report of the results of the test shall be signed by the party conducting the test and provided to the building official. Testing shall be performed at any time after creation of all penetrations of the building thermal envelope.
During testing:
1. Exterior windows and doors, fireplace and stove doors shall be closed, but not sealed, beyond the intended weatherstripping or other infiltration control measures;
2. Dampers including exhaust, intake, makeup air, backdraft and flue dampers shall be closed, but not sealed beyond intended infiltration control measures;
3. Interior doors, if installed at the time of the test, shall be open;
4. Exterior doors for continuous ventilation systems and heat recovery ventilators shall be closed and sealed;
5. Heating and cooling systems, if installed at the time of the test, shall be turned off; and
6. Supply and return registers, if installed at the time of the test, shall be fully open.
DeletedNew 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.
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 CodeUniform Mechanical Code
or Section M1601.4.1 of this code as applicable.
Exceptions:
1. Air-impermeable spray foam products shall be permitted to be applied without additional joint seals.
2. Where a duct connection is made that is partially inaccessible, three screws or rivets shall be equally spaced on the exposed portion of the joint so as to prevent a hinge effect.
3. Continuously welded and locking-type longitudinal joints and seams in ducts operating at static pressures less than 2 inches of water column (500 Pa) pressure classification shall not require additional closure systems.
Duct tightness shall be verified by either of the following:
1. Postconstruction test: Total leakage shall be less than or equal to 4 cfm (113.3 L/min) per 100 square feet (9.29 m2) of conditioned floor area when tested at a pressure differential of 0.1 inches w.g. (25 Pa) across the entire system, including the manufacturer's air handler enclosure. All register boots shall be taped or otherwise sealed during the test.
2. Rough-in test: Total leakage shall be less than or equal to 4 cfm (113.3 L/min) per 100 ft2 (9.29 m2) of conditioned floor area when tested at a pressure differential of 0.1 inches w.g. (25 Pa) across the system, including the manufacturer's air handler enclosure. All registers shall be taped or otherwise sealed during the test. If the air handler is not installed at the time of the test, total leakage shall be less than or equal to 3 cfm (85 L/min) per 100 square feet (9.29 m2) of conditioned floor area.
Exception: The total leakage test is not required for ducts and air handlers located entirely within the building thermal envelope.
Air handlers shall have a manufacturer's designation for an air leakage of no more than 2 percent of the design air flow rate when tested in accordance with ASHRAE 193.
Building framing cavities shall not be used as ducts or plenums.
Mechanical system piping capable of carrying fluids above 105°F (41°C) or below 55°F (13°C) shall be insulated to a minimum of R-3.
Piping insulation exposed to weather shall be protected from damage, including that caused by sunlight, moisture, equipment maintenance, and wind, and shall provide shielding from solar radiation that can cause degradation of the material. Adhesive tape shall not be permitted.
Circulating hot water systems shall be provided with an automatic or readily accessible manual switch that can turn off the hot-water circulating pump when the system is not in use.
Insulation for hot water pipe with a minimum thermal resistance (R-value) of R-3 shall be applied to the following:
1. Piping larger than 3/4-inch nominal diameter.
2. Piping serving more than one dwelling unit.
3. Piping from the water heater to kitchen outlets.
4. Piping located outside the conditioned space.
5. Piping from the water heater to a distribution manifold.
6. Piping located under a floor slab.
7. Buried piping.
8. Supply and return piping in recirculation systems other than demand recirculation systems.
9. Piping with run lengths greater than the maximum run lengths for the nominal pipe diameter given in Table N1103.4.2.
All remaining piping shall be insulated to at least R-3 or meet the run length requirements of Table N1103.4.2.
TABLE N1103.4.2 (R403.4.2)
MAXIMUM RUN LENGTH (feet)a
| Nominal pipe diameter of largest diameter pipe in the run (inch) | 3/8 | 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.
a. Total length of all piping from the distribution manifold or the recirculation loop to a point of use.
The building shall be provided with ventilation that meets the requirements of Section M1507 of this code or the International Mechanical CodeUniform Mechanical Code, as applicable, or with other approved means of ventilation. Outdoor air intakes and exhausts shall have automatic or gravity dampers that close when the ventilation system is not operating.
When installed to function as a whole-house mechanical ventilation system fans shall meet the efficacy requirements of Table N1103.5.1.
Exception: Where whole-house mechanical ventilation fans are integral to tested and listed HVAC equipment, they shall be powered by an electronically commutated motor.
TABLE N1103.5.1 (R403.5.1)
MECHANICAL VENTILATION SYSTEM FAN EFFICACY
| FAN LOCATION | AIR FLOW RATE MINIMUM (CFM) | MINIMUM EFFICACYa (CFM/WATT) | AIR FLOW RATE MAXIMUM (CFM) |
| 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. |
| a. When tested in accordance with HVI Standard 916 |
Heating and cooling equipment shall be sized in accordance with ACCA Manual S based on building loads calculated in accordance with ACCA Manual J or other approved heating and cooling calculation methodologies.
Systems serving multiple dwelling units shall comply with Sections C403 and C404 of the IECC—Commercial Provisions in lieu of Section N1103.
Snow- and ice-melting systems, supplied through energy service to the building, shall include automatic controls capable of shutting off the system when the pavement temperature is above 50°F (10°C), and no precipitation is falling and an automatic or manual control that will allow shutoff when the outdoor temperature is above 40°F (4.8°C).
All heaters shall be equipped with a readily accessible on-off switch that is mounted outside of the heater to allow shutting off the heater without adjusting the thermostat setting. Gas-fired heaters shall not be equipped with constant burning pilot lights.
Time switches or other control method that can automatically turn off and on heaters and pumps according to a preset schedule shall be installed on all heaters and pumps. Heaters, pumps and motors that have built in timers shall be deemed in compliance with this requirement.
Exceptions:
1. Where public health standards require 24-hour pump operation.
2. Where pumps are required to operate solar-and waste-heat-recovery pool heating systems.
Heated pools and inground permanently installed spas shall be provided with a vapor-retardant cover.
Exception: Pools deriving over 70 percent of the energy for heating from site-recovered energy, such as a heat pump or solar energy source computed over an operating season.
A minimum of 75 percent of the lamps in permanently installed lighting fixtures shall be high-efficacy lamps or a minimum of 75 percent of the permanently installed lighting fixtures shall contain only high-efficacy lamps.
Exception: Low-voltage lighting shall not be required to utilize high-efficiency lamps.
Fuel gas lighting systems shall not have continuously burning pilot lights.
This section establishes criteria for compliance using simulated energy performance analysis. Such analysis shall include heating, cooling, and service water heating energy only.
Compliance with this section requires that the mandatory provisions identified in Section N1101.15 be met. All supply and return ducts not completely inside the building thermal envelope shall be insulated to a minimum of R-6.
Compliance based on simulated energy performance requires that a proposed residence (proposed design) be shown to have an annual energy cost that is less than or equal to the annual energy cost of the standard reference design. Energy prices shall be taken from a source approved by the building official, such as the Department of Energy, Energy Information Administration's State Energy Price and Expenditure Report. Building officials shall be permitted to require time-of-use pricing in energy cost calculations.
Exception: The energy use based on source energy expressed in Btu (J) or Btu per square foot (J/m2) of conditioned floor area shall be permitted to be substituted for the energy cost. The source energy multiplier for electricity shall be 3.16. The source energy multiplier for fuels other than electricity shall be 1.1.
Documentation 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.
Except as specified by this section, the standard reference design and proposed design shall be configured and analyzed using identical methods and techniques.
The standard reference design and proposed design shall be configured and analyzed as specified by Table N1105.5.2(1). Table N1105.5.2(1) shall include by reference all notes contained in Table N1102.1.1.
TABLE N1105.5.2(1) [R405.5.2(1)]
SPECIFICATIONS FOR THE STANDARD REFERENCE AND PROPOSED DESIGNS
| BUILDING COMPONENT | STANDARD REFERENCE DESIGN | PROPOSED DESIGN |
| Above-grade walls | Type: mass wall if proposed wall is mass; otherwise wood frame. Gross area: same as proposed U-factor: from Table N1102.1.3 Solar absorptance = 0.75 Remittance = 0.90 | As proposed As proposed As proposed As proposed As proposed |
| Basement and crawl space walls | Type: same as proposed Gross area: same as proposed U-factor: from Table N1102.1.3, with insulation layer on interior side of walls. | As proposed As proposed As proposed |
| Above-grade floors | Type: wood frame Gross area: same as proposed U-factor: from Table N1102.1.3 | As proposed As proposed As proposed |
| Ceilings | Type: wood frame Gross area: same as proposed U-factor: from Table N1102.1.3 | As proposed As proposed As proposed |
| Roofs | Type: composition shingle on wood sheathing Gross area: same as proposed Solar absorptance = 0.75 Emittance = 0.90 | As proposed As proposed As proposed As proposed |
| 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 Orientation: North U-factor: same as fenestration from Table N1102.1.3. | As proposed As proposed As proposed |
| Glazinga | Total areab = (a) The proposed glazing area; where proposed glazing area is less than 15% of the conditioned floor area. (b) 15% of the conditioned floor area; where the proposed glazing area is 15% or more of the conditioned floor area. | As proposed |
| Orientation: equally distributed to four cardinal compass orientations (N, E, S & W). | As proposed | |
| U-factor: from Table N1102.1.3 | As proposed | |
| SHGC: From Table N1102.1.1 except that for climates with no requirement (NR) SHGC = 0.40 shall be used. Interior shade fraction: 0.92-(0.21 × SHGC for the standard reference design) External shading: none | As proposed 0.92-(0.21 × SHGC as proposed) As proposed | |
| Skylights | None | As proposed |
| Thermally isolated sunrooms | None | As proposed |
(continued)
TABLE N1105.5.2(1) [R405.5.2(1)]—continued
SPECIFICATIONS FOR THE STANDARD REFERENCE AND PROPOSED DESIGNS
| BUILDING COMPONENT | STANDARD REFERENCE DESIGN | PROPOSED DESIGN |
| Air exchange rate | Air leakage rate of 5 air changes per hour in Zones 1 and 2, and 3 air changes per hour in Zones 3 through 8 at a pressure of 0.2 inches w.g (50 Pa). The mechanical ventilation rate shall be in addition to the air leakage rate and the same as in the proposed design, but no greater than 0.01 × CFA + 7.5 × (Nbr + 1) where: CFA = conditioned floor area Nbr = number of bedrooms Energy recovery shall not be assumed for mechanical ventilation. | For residences that are not tested, the same air leakage rate as the standard reference design. For tested residences, the measured air exchange ratec. The mechanical ventilation rated shall be in addition to the air leakage rate and shall be as proposed. |
| Mechanical ventilation | None, except where mechanical ventilation is specified by the proposed design, in which case: Annual vent fan energy use: kWh/yr = 0.03942 × CFA + 29.565 × (Nbr+ 1) where: CFA = conditioned floor area Nbr= number of bedrooms | As proposed |
| Internal gains | IGain = 17,900 + 23.8 × CFA + 4104 × Nbr(Btu/day per dwelling unit) | Same as standard reference design. |
| Internal mass | An internal mass for furniture and contents of 8 pounds per square foot of floor area. | Same as standard reference design, plus any additional mass specifically designed as a thermal storage elemente but not integral to the building envelope or structure. |
| Structural mass | For masonry floor slabs, 80% of floor area covered by R-2 carpet and pad, and 20% of floor directly exposed to room air. For masonry basement walls, as proposed, but with insulation required by Table N1102.1.3 (R402.1.3) located on the interior side of the walls. For other walls, for ceilings, floors, and interior walls, wood frame construction. | As proposed As proposed As proposed |
| Heating systems f, g | As proposed for other than electric heating without a heat pump. Where the proposed design utilizes electric heating without a heat pump the standard reference design shall be an air source heat pump meeting the requirements of Section C403 of the International Energy Conservation Code—Commercial Provisions. Capacity: sized in accordance with Section N1103.6 | As proposed |
| Cooling systemsf, h | As proposed Capacity: sized in accordance with Section N1103.6. | As proposed |
| Service water Heatingf, g, h, i | As proposed Use: same as proposed design | As proposed gal/day = 30 + (10 × Nbr) |
| Thermal distribution systems | 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.
a. Glazing shall be defined as sunlight-transmitting fenestration, including the area of sash, curbing or other framing elements, that enclose conditioned space. Glazing includes the area of sunlight-transmitting fenestration assemblies in walls bounding conditioned basements. For doors where the sunlight-transmitting opening is less than 50 percent of the door area, the glazing area is the sunlight transmitting opening area. For all other doors, the glazing area is the rough frame opening area for the door including the door and the frame.
b. For residences with conditioned basements, R-2 and R-4 residences and townhouses, the following formula shall be used to determine glazing area:
AF = As × FA × F
where:
AF = Total glazing area.
As= Standard reference design total glazing area.
FA = (Above-grade thermal boundary gross wall area)/(above-grade boundary wall area + 0.5 × below-grade boundary wall area).
F = (Above-grade thermal boundary wall area)/(above-grade thermal boundary wall area + common wall area) or 0.56, whichever is greater.
and where:
Thermal boundary wall is any wall that separates conditioned space from unconditioned space or ambient conditions.
Above-grade thermal boundary wall is any thermal boundary wall component not in contact with soil.
Below-grade boundary wall is any thermal boundary wall in soil contact.
Common wall area is the area of walls shared with an adjoining dwelling unit.
L and CFA are in the same units.
c. Where required by the building official, testing shall be conducted by an approved party. Hourly calculations as specified in the ASHRAE Handbook of Fundamentals, or the equivalent shall be used to determine the energy loads resulting from infiltration.
d. The combined air exchange rate for infiltration and mechanical ventilation shall be determined in accordance with Equation 43 of 2001 ASHRAE Handbook of Fundamentals, page 26.24 and the “Whole-house Ventilation” provisions of 2001 ASHRAE Handbook of Fundamentals, page 26.19 for intermittent mechanical ventilation.
e. Thermal storage element shall mean a component not part of the floors, walls or ceilings that is part of a passive solar system, and that provides thermal storage such as enclosed water columns, rock beds, or phase-change containers. A thermal storage element must be in the same room as fenestration that faces within 15 degrees (0.26 rad) of true south, or must be connected to such a room with pipes or ducts that allow the element to be actively charged.
f. For a proposed design with multiple heating, cooling or water heating systems using different fuel types, the applicable standard reference design system capacities and fuel types shall be weighted in accordance with their respective loads as calculated by accepted engineering practice for each equipment and fuel type present.
g. For a proposed design without a proposed heating system, a heating system with the prevailing federal minimum efficiency shall be assumed for both the standard reference design and proposed design.
h. For a proposed design home without a proposed cooling system, an electric air conditioner with the prevailing federal minimum efficiency shall be assumed for both the standard reference design and the proposed design.
i. For a proposed design with a nonstorage-type water heater, a 40-gallon storage-type water heater with the prevailing federal minimum energy factor for the same fuel as the predominant heating fuel type shall be assumed. For the case of a proposed design without a proposed water heater, a 40-gallon storage-type water heater with the prevailing federal minimum efficiency for the same fuel as the predominant heating fuel type shall be assumed for both the proposed design and standard reference design.
TABLE N1105.5.2(2) [R405.5.2(2)]
DEFAULT DISTRIBUTION SYSTEM EFFICIENCIES FOR PROPOSED DESIGNSa
| DISTRIBUTION SYSTEM CONFIGURATION AND CONDITION | FORCED AIR SYSTEMS | HYDRONIC SYSTEMSb |
| Distribution system components located in unconditioned space | — | 0.95 |
| Untested distribution systems entirely located in conditioned spacec | 0.88 | 1 |
| “Ductless“ systemsd | 1 | — |
For SI: 1 cubic foot per minute = 0.47 L/s, 1 square foot = 0.093m2, 1 pound per square inch = 6895 Pa, 1 inch water gauge = 1250 Pa.
a. Default values given by this table are for untested distribution systems, which must still meet minimum requirements for duct system insulation.
b. Hydronic systems shall mean those systems that distribute heating and cooling energy directly to individual spaces using liquids pumped through closed-loop piping and that do not depend on ducted, forced airflow to maintain space temperatures.
c. Entire system in conditioned space shall mean that no component of the distribution system, including the air handler unit, is located outside of the conditioned space.
d. Ductless systems shall be allowed to have forced airflow across a coil but shall not have any ducted airflow external to the manufacturer's air handler enclosure.
Calculation 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.