Washington Administrative Code

HEAT TRAP. An arrangement of piping and fittings, such as elbows, or a commercially available heat trap that prevents thermosyphoning of hot water during standby periods.HEAT TRAP, PIPE CONFIGURED. A pipe configured heat trap is either, as applicable:1. A device specifically desi…

IEC DESIGN H MOTOR. An electric motor that meets all of the following:1. It is an induction motor designed for use with three-phase power.2. It contains a cage rotor.3. It is capable of direct-on-line starting.4. It has 4, 6 or 8 poles.5. It is rated from 0.4 kW to 1600 kW at a f…

[Statutory Authority: RCW 19.27A.020, 19.27A.025 and chapters 19.27 and 34.05 RCW. WSR 13-04-056, § 51-11C-20210, filed 2/1/13, effective 7/1/13.]

[Statutory Authority: RCW 19.27A.020, 19.27A.025 and chapters 19.27 and 34.05 RCW. WSR 13-04-056, § 51-11C-20211, filed 2/1/13, effective 7/1/13.]

LABELED. Equipment, materials or products to which have been affixed a label, seal, symbol or other identifying mark of a nationally recognized testing laboratory, approvedagency or other organization concerned with product evaluation that maintains periodic inspection of the pro…

MANUAL. Capable of being operated by personal intervention (see "Automatic").MASS TRANSFER DECK SLAB. A concrete slab designed to transfer structural load from the building perimeter wall or column line above, laterally to an offset wall or column line below, and which has condit…

NAMEPLATE HORSEPOWER. The nominal motor output power rating stamped on the motor nameplate.NEMA DESIGN A MOTOR. A squirrel-cage motor that meets all of the following:1. It is designed to withstand full-voltage starting and developing locked-rotor torque as shown in paragraph 12.3…

OCCUPANT SENSOR CONTROL. An automatic control device or system that detects the presence or absence of people within an area and causes lighting, equipment or appliances to be regulated accordingly.ON-SITE RENEWABLE ENERGY. Energy from renewable energy resources harvested at the …

PERSONAL WIRELESS SERVICE FACILITY. A wireless communication facility (WCF), including a microcell, which is a facility for the transmission and/or reception of radio frequency signals and which may include antennas, equipment shelter or cabinet, transmission cables, a support st…

[Statutory Authority: RCW 19.27A.020, 19.27A.025 and chapters 19.27 and 34.05 RCW. WSR 13-04-056, § 51-11C-20217, filed 2/1/13, effective 7/1/13.]

RADIANT HEATING SYSTEM. A heating system that transfers heat to objects and surfaces within a conditioned space, primarily by infrared radiation.READY ACCESS (TO). That which enables a device, appliance or equipment to be directly reached, without requiring the removal or movemen…

SATURATED-CONDENSING TEMPERATURE. The saturation temperature corresponding to the measured refrigerant pressure at the condenser inlet for single component and azeotropic refrigerants, and the arithmetic average of the dew point and bubble point temperatures corresponding to the …

TEMPERATURE MAINTENANCE. The system used to maintain the temperature of the building service hot water delivery system, typically by circulation and reheating or by a heat trace system.TEMPORARY GROWING STRUCTURE. A temporary growing structure has sides and roof covered with poly…

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 …

VARIABLE REFRIGERANT FLOW SYSTEM. An engineered direct-expansion (DX) refrigerant system that incorporates a common condensing unit, at least one variable capacity compressor, a distributed refrigerant piping network to multiple indoor fan heating and cooling units each capable o…

WALK-IN COOLER. An enclosed storage space capable of being refrigerated to temperatures above 32°F (0°C) and less than 55°F (12.8°C) that can be walked into, has a ceiling height of not less than 7 feet (2134 mm) and has a total chilled storage area of less than 3,000 square feet…

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.[Statutory Authority: RCW 19.27A.020, 19.27A.025 and chapters 19.27 and …

[Statutory Authority: RCW 19.27A.020, 19.27A.025 and chapters 19.27 and 34.05 RCW. WSR 13-04-056, § 51-11C-30000, filed 2/1/13, effective 7/1/13.]Reviser's note: The brackets and enclosed material in the text of the above section occurred in the copy filed by the agency.

C301.1 General. Climate zones from Table C301.1 shall be used in determining the applicable requirements from Chapter 4.Table C301.1Climate Zones and Moisture RegimesDesignations by State and CountyKey: A - Moist, B - Dry, C - Marine. Absence of moisture designation indicates moi…

C302.1 Interior design conditions. 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.C302.2 Exterior design conditions. The heating or cooling outdoor design tempera…

[Statutory Authority: RCW 19.27A.020, 19.27A.025 and chapters 19.27 and 34.05 RCW. WSR 13-04-056, § 51-11C-30300, filed 2/1/13, effective 7/1/13.]

C303.1 Identification. Materials, systems and equipment shall be identified in a manner that will allow a determination of compliance with the applicable provisions of this code.C303.1.1 Building thermal envelope insulation. An R-value identification mark shall be applied by the …

Table C303.1.3(1)Default Glazed Window, Glass Door and Skylight U-Factors Window and Glass Door FRAME TYPESINGLE PANEDOUBLE PANESKY-LIGHTMetal1.200.80 Metal with Thermal Break1.100.65See TableC303.1.3(4)Nonmetal or Metal Clad0.950.55 Glazed Block0.60[Statutory Authority: RCW 19.2…

Table C303.1.3(2)Default Opaque Door U-FactorsSee Appendix A, Section A107[Statutory Authority: RCW 19.27A.020, 19.27A.025, 19.27A.160 and chapter 19.27 RCW. WSR 19-24-040, § 51-11C-303132, filed 11/26/19, effective 7/1/20. Statutory Authority: RCW 19.27A.020, 19.27A.025 and chap…

Table C303.1.3(3)Default Glazed Fenestration SHGC and VT SINGLE GLAZEDDOUBLE GLAZEDGLAZE BLOCK ClearTintedClearTintedSHGC 0.400.400.400.400.40VT 0.60.30.60.30.6[Statutory Authority: RCW 19.27A.020, 19.27A.025 and chapters 19.27 and 34.05 RCW. WSR 13-04-056, § 51-11C-303133, filed…

Table C303.1.3(4)Default U-Factors for Skylights Frame Type AluminumWithout Thermal BreakAluminum With Thermal BreakReinforced Vinyl/Aluminum-Clad Wood or VinylWood or Vinyl-Clad Wood/Vinyl Without ReinforcingFenestration TypeSingle Glazing glassU-1.58U-1.51U-1.40U-1.18 acrylic/p…

Table C303.1.3(5)Small Business Compliance TableDefault U-Factors for Vertical GlazingVertical Glazing DescriptionFrame TypeAny FrameAluminum Thermal Break2Wood/Vinyl/FiberglassPanesLow-e1SpacerFillDouble3AAnyArgon0.480.410.32 BAnyArgon0.460.390.30 CAnyArgon0.440.370.28 CHighPerf…

Table C303.1.5U-Factors for Spandrel Panels and Glass Curtain Walls Rated R-Value of Insulation Between Framing MembersNoneR-4R-7R-10R-15R-20R-25R-30Frame TypeSpandrel Panel ABCDEFGHAluminum without Thermal BreakSingle glass pane, stone or metal panel10.3600.2420.2220.2120.2030.1…

C303.2 Installation. Materials, systems and equipment shall be installed in accordance with the manufacturer's instructions and the International Building Code.C303.2.1 Protection of exposed foundation insulation. Insulation applied to the exterior of basement walls, crawlspace w…

[Statutory Authority: RCW 19.27A.020, 19.27A.025, 19.27A.160 and chapter 19.27 RCW. WSR 19-24-040, § 51-11C-30330, filed 11/26/19, effective 7/1/20. Statutory Authority: RCW 19.27A.020, 19.27A.025 and chapters 19.27 and 34.05 RCW. WSR 13-04-056, § 51-11C-30330, filed 2/1/13, effe…

[Statutory Authority: RCW 19.27A.020, 19.27A.025 and chapters 19.27 and 34.05 RCW. WSR 13-04-056, § 51-11C-40000, filed 2/1/13, effective 7/1/13.]Reviser's note: The brackets and enclosed material in the text of the above section occurred in the copy filed by the agency.

C401.1 Scope. The provisions in this chapter are applicable to commercial buildings and their building sites.C401.2 Application. Commercial buildings shall comply with the fossil fuel compliance path according to Section C401.3, or with one of the following:1. Prescriptive compli…

[Statutory Authority: RCW 19.27A.020, 19.27A.025 and chapters 19.27 and 34.05 RCW. WSR 13-04-056, § 51-11C-40200, filed 2/1/13, effective 7/1/13.]

C402.1 General. Building thermal envelope assemblies for buildings that are intended to comply with the code on a prescriptive basis, in accordance with the compliance path described in Item 1 of Section C401.2, shall comply with the following:1. The opaque portions of the buildi…

C402.1.1Low energy buildings, semi-heated buildings and greenhouses. Low energy buildings shall comply with Section C402.1.1.1. Semi-heated buildings and spaces shall comply with Section C402.1.1.2. Greenhouses shall comply with Section C402.1.1.3.C402.1.1.1 Low energy buildings.…

C402.1.2 Equipment buildings. Buildings that comply with all of the following shall be exempt from the building thermal envelope provisions of this code:1. Are separate buildings with floor area no more than 500 square feet (50 m2).2. Are intended to house electric equipment with…

Table C402.1.3Opaque Thermal Envelope Insulation ComponentMinimum Requirements, R-value Methoda, jCLIMATE ZONE5 AND MARINE 4 All OtherGroup RRoofsInsulation entirely above deckR-38ciR-38ciMetal buildingsbR-25 + R-22 LSR-25 + R-22 LSAttic and otherR-49R-49Walls, Above GradeiMasshR…

C402.1.3 Insulation component R-value-based method.Building thermal envelope opaque assemblies shall comply with the requirements of Section C402.2 based on the climate zone specified in Chapter 3. For opaque portions of the building thermal envelope intended to comply on an insu…

C402.1.4 Assembly U-factor, C-factor, or F-factor-based method. Building thermal envelope opaque assemblies shall meet the requirements of Section C402.2 based on the climate zone specified in Chapter 3. Building thermal envelope opaque assemblies intended to comply on an assembl…

Table C402.1.4Opaque Thermal Envelope Requirementsa,fCLIMATE ZONE5 AND MARINE 4 All OtherGroup RRoofsInsulation entirely above deckU-0.027U-0.027Metal buildingsU-0.031U-0.031Attic and otherU-0.021U-0.021Joist or single rafterU-0.027U-0.027Walls, Above GradekMassd,gU-0.104U-0.078M…

Table C402.1.4.2Effective R-values For Steel Stud Wall AssembliesNOMINAL STUD DEPTH (inches)SPACING OF FRAMING (inches)CAVITYR-VALUE (insulation)CORRECTION FACTOR (Fc)EFFECTIVER-VALUE (ER)(Cavity R-Value × Fc) 3 1/216130.465.98 150.436.45 3 1/224130.557.15 150.527.80 616190.377.0…

C402.1.5 Component performance alternative. Building envelope values and fenestration areas determined in accordance with Equation 4-2 shall be permitted in lieu of compliance with the U-factors and F-factors in Table C402.1.4 and C402.4 and the maximum allowable fenestration are…

C402.2 Specific building thermal envelope insulation requirements. Insulation in building thermal envelope opaque assemblies shall comply with Sections C402.2.1 through C402.2.9 and Table C402.1.3.Where this section refers to installing insulation levels as specified in Section C…

C402.2.1Roof assembly. The minimum thermal resistance (R-value) of the insulating material installed either between the roof framing or continuously on the roof assembly shall be as specified in Table C402.1.3, based on construction materials used in the roof assembly.EXCEPTIONS:…

[Statutory Authority: RCW 19.27A.020, 19.27A.025, 19.27A.160 and chapters 19.27A and 19.27 RCW. WSR 22-14-091, 23-12-101, and 23-20-021, § 51-11C-402211, filed 7/1/22, 6/7/23, and 9/25/23, effective 3/15/24. Statutory Authority: RCW 19.27A.020, 19.27A.025, 19.27A.160 and chapter …

C402.2.2 Above-grade walls. The minimum thermal resistance (R-value) of materials installed in the wall cavity between the framing members and continuously on the walls shall be as specified in Table C402.1.3, based on framing type and construction materials used in the wall asse…

C402.2.3 Floors. The thermal properties (component R-values or assembly U- or F-factors) of floor assemblies over outdoor air or unconditioned space shall be as specified in Table C402.1.3 or C402.1.4 based on the construction materials used in the floor assembly. Floor framing c…

C402.2.4 Slabs-on-grade. The minimum thermal resistance (R-value) of the insulation for unheated or heated slab-on-grade floors designed in accordance with the R-value method of Section C402.1.3 shall be as specified in Table C402.1.3.C402.2.4.1 Insulation installation. Where ins…

C402.2.5 Below-grade walls. The R-value of the insulating material installed in, or continuously on, the below-grade walls shall be in accordance with Table C402.1.3. The U-factor or R-value required shall extend to the level of the lowest floor of the conditioned space enclosed …

C402.2.6 Insulation of radiant heating systems.Radiant heating system panels, and their associated components that are installed in interior or exterior assemblies shall be insulated to an R-value of not less than R-3.5 on all surfaces not facing the space being heated. Radiant h…