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

Climate zones from Table R301.1 shall be used in determining the applicable requirements from Chapter 4.

TABLE R301.1

CLIMATE ZONES, MOISTURE REGIMES, AND WARM-HUMID DESIGNATIONS BY STATE AND COUNTY

Key: A - Moist, B - Dry, C - Marine.
Absence of moisture designation indicates
moisture regime is irrelevant.
WASHINGTON
5B Adams 4C Lewis
5B Asotin 5B Lincoln
5B Benton 4C Mason
5B Chelan 5B Okanogan
4C Clallam 4C Pacific
4C Clark 5B Pend Oreille
5B Columbia 4C Pierce
4C Cowlitz 4C San Juan
5B Douglas 4C Skagit
5B Ferry 5B Skamania
5B Franklin 4C Snohomish
5B Garfield 5B Spokane
5B Grant 5B Stevens
4C Grays Harbor 4C Thurston
4C Island 4C Wahkiakum
4C Jefferson 5B Walla Walla
4C King 4C Whatcom
4C Kitsap 5B Whitman
5B Kittitas 5B Yakima
5B Klickitat
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.
The heating or cooling outdoor design temperatures shall be selected from Appendix RC.
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 (fiber-glass 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. For insulated siding, the R-value shall be labeled on the product's package and shall be listed on the certification. The insulation installer shall sign, date and post the certification in a conspicuous location on the job site.

Exception: For roof insulation installed above the deck, the R-value shall be labeled as required by the material standards specified in Table 1508.2 of the International Building Code or Table R906.2 of the International Residential Code.

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.

Exception: Where required, garage door U-factors shall be determined in accordance with either NFRC 100 or ANSI/DASMA 105.

U-factors shall be determined by an accredited, independent laboratory, and labeled and certified by the manufacturer. Products lacking such a labeled U-factor shall be assigned a default U-factor from Table R303.1.3(1), R303.1.3(2) or R303.1.3(4). 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 R303.1.3(3).


Exceptions:

  1. Units without NFRC ratings produced by a small business may be assigned default U-factors from Table R303.1.3(5) for vertical fenestration.
  2. Owner-built, nonoperable wood frame window consisting of a double pane unit with low-e (E=0.04 or less), 1/2-inch airspace with argon fill.

TABLE R303.1.3(1)

DEFAULT GLAZED WINDOW, GLASS DOOR AND SKYLIGHT U-FACTORS

FRAME TYPE WINDOW AND
GLASS DOOR
SKYLIGHT
SINGLE
PANE
DOUBLE
PANE
Metal 1.20 0.80 See
Table R303.1.3(4)
Metal with Thermal Breaka 1.10 0.65
Nonmetal or Metal Clad 0.95 0.55
Glazed Block 0.60
  1. Metal Thermal Break = A metal thermal break framed window shall incorporate the following minimum design characteristics:

    1. The thermal conductivity of the thermal break material shall be not more than 3.6 Btu-in/h/ft2/°F;
    2. The thermal break material must produce a gap in the frame material of not less than 0.210 inches; and
    3. All metal framing members of the products exposed to interior and exterior air shall incorporate a thermal break meeting the criteria in Items 1 and 2 above.

TABLE R303.1.3(2)

DEFAULT OPAQUE DOOR U-FACTORS

DOOR TYPE NO GLAZED SINGLE
GLAZING
DOUBLE
GLAZING WITH
1/4 in. AIRSPACE
DOUBLE
GLAZING WITH
1/2 in. AIRSPACE
DOUBLE GLAZING
WITH e=0.10,
1/2 in. ARGON
SWINGING DOORS (Rough opening — 38 in. x 82 in.)
Slab Doors
Wood slab in wood framea 0.46
6% glazed fenestration (22 in. × 8 in. lite) 0.48 0.47 0.46 0.44
25% glazed fenestration (22 in. × 36 in. lite) 0.58 0.48 0.46 0.42
45% glazed fenestration (22 in. × 64 in. lite) 0.69 0.49 0.46 0.39
More than 50% glazed fenestration Use Table R303.1.3(1)
Insulated steel slab with wood edge in wood framea 0.16
6% glazed fenestration (22 in. × 8 in. lite) 0.21 0.20 0.19 0.18
25% glazed fenestration (22 in. × 36 in. lite) 0.39 0.28 0.26 0.23
45% glazed fenestration (22 in. × 64 in. lite) 0.58 0.38 0.35 0.26
More than 50% glazed fenestration Use Table R303.1.3(1)
Foam insulated steel slab with metal edge in steel frameb 0.37
6% glazed fenestration (22 in. × 8 in. lite) 0.44 0.42 0.41 0.39
25% glazed fenestration (22 in. × 36 in. lite) 0.55 0.50 0.48 0.44
45% glazed fenestration (22 in. × 64 in. lite) 0.71 0.59 0.56 0.48
More than 50% glazed fenestration Use Table R303.1.3(1)
Cardboard honeycomb slab with metal edge in steel frameb 0.61
Style and Rail Doors
Sliding glass doors/French doors Use Table R303.1.3(1)
Site-Assembled Style and Rail Doors
Aluminum in aluminum frame 1.32 0.99 0.93 0.79
Aluminum in aluminum frame with thermal break 1.13 0.80 0.74 0.63

For SI: 1 inch = 25.4 mm.

Note: Appendix RA Tables RA107.1(2) through RA107.1(4) may also be used if applicable.

  1. Thermally broken sill (add 0.03 for nonthermally broken sill).
  2. Nonthermally broken sill.

TABLE 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

TABLE R303.1.3(4)

DEFAULT U-FACTORS FOR SKYLIGHTSa, b, c, d

  FRAME TYPE
FENESTRATION TYPE Aluminum
Without Thermal
Break
Aluminum
With Thermal
Break
Reinforced
Vinyl/Aluminum-Clad
Wood or Vinyl
Wood or Vinyl-clad
Wood/Vinyl without
Reinforcing
Single Glazing        
Glass
Acrylic/polycarb
U-1.58
U-1.52
U-1.51
U-1.45
U-1.40
U-1.34
U-1.18
U-1.11
         
Double Glazing
Air
Argon
U-1.05
U-1.02
U-0.89
U-0.86
U-0.84
U-0.80
U-0.67
U-0.64
Double Glazing, e=0.20
Air
Argon
U-0.96
U-0.91
U-0.80
U-0.75
U-0.75
U-0.70
U-0.59
U-0.54
Double Glazing, e=0.10
Air
Argon
U-0.94
U-0.89
U-0.79
U-0.73
U-0.74
U-0.68
U-0.58
U-0.52
Double Glazing, e=0.05
Air
Argon
U-0.93
U-0.87
U-0.78
U-0.71
U-0.73
U-0.66
U-0.56
U-0.50
         
Triple Glazing
Air
Argon
U-0.90
U-0.87
U-0.70
U-0.69
U-0.67
U-0.64
U-0.51
U-0.48
Triple Glazing, e=0.20
Air
Argon
U-0.86
U-0.82
U-0.68
U-0.63
U-0.63
U-0.59
U-0.47
U-0.43
Triple Glazing, e=0.20 on 2 surfaces
Air
Argon
U-0.82
U-0.79
U-0.64
U-0.60
U-0.60
U-0.56
U-0.44
U-0.40
Triple Glazing, e=0.10 on 2 surfaces
Air
Argon
U-0.81
U-0.77
U-0.62
U-0.58
U-0.58
U-0.54
U-0.42
U-0.38
         
Quadruple Glazing, e=0.10 on 2 surfaces
Air
Argon
Krypton
U-0.78
U-0.74
U-0.70
U-0.59
U-0.56
U-0.52
U-0.55
U-0.52
U-0.48
U-0.39
U-0.36
U-0.32
  1. U-factors are applicable to glass and plastic, flat and domed units, all spacers and gaps.
  2. Emissivities shall be less than or equal to the value specified.
  3. Gap fill shall be assumed to be air unless there is a minimum of 90% Argon or Krypton.
  4. Aluminum frame with thermal break is as defined in Footnote a, Item 1 to Table R303.1.3(1).

TABLE R303.1.3(5)

SMALL BUSINESS COMPLIANCE TABLE DEFAULT U-FACTORS FOR VERTICAL FENESTRATION

VERTICAL FENESTRATION DESCRIPTION FRAME TYPE
Any Frame Aluminum
Thermal Breakb
Wood/Vinyl/
Fiberglass
Panes Low-e a Spacer Fill
Doublec A Any Argon 0.48 0.41 0.32
B Any Argon 0.46 0.39 0.30
C Any Argon 0.44 0.37 0.28
C High Performance Argon 0.42 0.35 Deemed to complye
Tripled A Any Air 0.50 0.44 0.26
B Any Air 0.45 0.39 0.22
C Any Air 0.41 0.34 0.20
Any double low-e Any Air 0.35 0.32 0.18

For SI: 1 inch = 25.4 mm.

  1. Low-eA (emissivity) shall be 0.24 to 0.16.
    Low-eB (emissivity) shall be 0.15 to 0.08.
    Low-eC (emissivity) shall be 0.07 or less.
  2. Aluminum Thermal Break = An aluminum thermal break framed window shall incorporate the following minimum design characteristics:

    1. The thermal conductivity of the thermal break material shall be not more than 3.6 Btu-in/h/ft2/°F;
    2. The thermal break material must produce a gap in the frame material of not less than 0.210 inches; and
    3. All metal framing members of the products exposed to interior and exterior air shall incorporate a thermal break meeting the criteria in Items 1 and 2 above.
  3. A minimum air space of 0.375 inches between panes of glass is required for double glazing.
  4. A minimum air space of 0.25 inches between panes of glass is required for triple glazing.
  5. Deemed to comply glazing shall not be used for performance compliance.
The thermal resistance (R-value) of insulation shall be determined in accordance with the U.S. Federal Trade Commission R-value rule (C.F.R. Title 16, Part 460) in units of h × ft2 × °F/Btu at a mean temperature of 75°F (24°C).
The thermal resistance (R-value) of insulated siding shall be determined in accordance with ASTM C1363. Installation for testing shall be in accordance with the manufacturer's installation instructions.
All materials, systems and equipment shall be installed in accordance with the manufacturer's installation instructions and the International Building Code or International Residential Code, as applicable.
Insulation applied to the exterior of basement walls, crawl-space 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.
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