Chapter 51-11C State Building Code adoption and amendment of the 2021 edition of the International Energy Conservation Code, Commercial.

C403.11 Mechanical systems located outside of the building thermal envelope. Mechanical systems providing heat outside of the thermal envelope of a building shall comply with Sections C403.11.1 through C403.11.3.C403.11.1 Heating outside a building. Systems installed to provide h…

C403.12 High efficiency single-zone variable air volume (VAV) systems. For HVAC systems subject to the requirements of Section C403.3.5 but utilizing Exception 2 of that section, a high efficiency single-zone VAV system may be provided without a separate parallel DOAS when the sy…

C403.13 Dehumidification in spaces for plant growth and maintenance. Equipment that dehumidifies building spaces used for plant growth and maintenance shall be one of the following:1. Stand-alone dehumidifiers that meet the following minimum integrated energy factors as measured …

[Statutory Authority: RCW 19.27A.020, 19.27A.025, 19.27A.160 and chapter 19.27 RCW. WSR 19-24-040, § 51-11C-40400, 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-40400, filed 2/1/13, effe…

C404.1 General. This section covers the minimum efficiency of, and controls for, service water-heating equipment and insulation of service hot water piping.EXCEPTION:Energy using equipment used by a manufacturing, industrial or commercial process other than maintaining comfort an…

C404.2 Service water-heating equipment performance efficiency. Water-heating equipment and hot water storage tanks shall meet the requirements of Table C404.2. The efficiency shall be verified through certification and listed under an approved certification program, or if no cert…

Table C404.2Minimum Performance of Water-Heating EquipmentEquipment TypeSize Category(input)Subcategory or Rating ConditionDraw PatternPerformance Requireda,jTest ProcedurebElectric table-top water heatersk≤ 12 kWc≥ 20 gal≤ 120 galVery smallLowMediumHighUEF ≥ 0.6323 - (0.0058 × V…

C404.3 Efficient heated water supply piping. Heated water supply piping shall be in accordance with Section C404.3.1 or C404.3.2. The flow rate through 1/4-inch (6.4 mm) piping shall be not greater than 0.5 gpm (1.9 L/m). The flow rate through 5/16-inch (7.9 mm) piping shall be n…

C404.4 Heat traps for hot water storage tanks. Storage tank-type water heaters and hot water storage tanks that have vertical water pipes connecting to the inlet and outlet of the tank shall be provided with integral heat traps at the vertical inlets and outlets or shall have pip…

C404.5 Water heater installation. Electric water heaters in unconditioned spaces or on concrete floors shall be placed on an incompressible, insulated surface with a minimum thermal resistance of R-10.[Statutory Authority: RCW 19.27A.020, 19.27A.025 and chapters 19.27 and 34.05 R…

C404.6 Insulation of piping. Piping from a water heater to the termination of the heated water fixture supply pipe shall be insulated in accordance with Table C403.10.3. On both the inlet and outlet piping of a storage water heater or heated water storage tank, the piping to a he…

C404.7 Heated-water circulating and heat trace temperature maintenance systems. Heated-water circulation systems for temperature maintenance shall be in accordance with Section C404.7.1. Electric resistance heat trace systems for temperature maintenance shall be in accordance wit…

C404.8 Demand recirculation controls.Demand recirculation water systems shall have controls that comply with both of the following:1. The controls shall start the pump upon receiving a signal from the action of a user of a fixture or appliance, sensing the presence of a user of a…

C404.9 Domestic hot water meters. Each individual dwelling unit in a Group R-2 occupancy with central service domestic hot water systems shall be provided with a domestic hot water meter to allow for domestic hot water billing based on actual domestic hot water usage.EXCEPTION:Dw…

C404.10 Drain water heat recovery units. Drain water heat recovery units shall comply with CSA B55.2. Potable waterside pressure loss shall be less than 10 psi (69 kPa) at maximum design flow. For Group R occupancies, the efficiency of drain water heat recovery unit efficiency sh…

C404.11 Energy consumption of pools and permanent spas. The energy consumption of pools and permanent spas shall be controlled by the requirements in Sections C404.11.1 through C404.11.4.C404.11.1 Heaters. Pool water heaters using electric resistance heating as the primary source…

C404.13 Servicewater pressure-booster systems. Service water pressure-booster systems shall be designed and configured such that the following apply:1. One or more pressure sensors shall be used to vary pump speed and/or start and stop pumps. The sensors shall either be located n…

C404.14 Demand responsive water heating. Electric storage water heaters with rated water storage volume between 40 and 120 gallons and a nameplate input rating equal to or less than 12kW shall be provided with demand responsive controls that comply with ANSI/CTA-2045-B Level 2 or…

C404.15 Commissioning. Service water heating systems shall be commissioned in accordance with Section C408.[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-40415, filed 7/1/22, 6/7/23…

[Statutory Authority: RCW 19.27A.020, 19.27A.025 and chapters 19.27 and 34.05 RCW. WSR 13-04-056, § 51-11C-40500, filed 2/1/13, effective 7/1/13.]

C405.1 General. Lighting system controls, the maximum lighting power for interior and exterior applications, electrical energy consumption, vertical and horizontal transportation systems, and minimum efficiencies for motors and transformers shall comply with this section.Sleeping…

C405.2 Lighting controls. Lighting systems shall be provided with controls that comply with one of the following:1. Lighting controls as specified in Sections C405.2.1 through C405.2.10.2. Luminaire-level lighting controls (LLLC) as specified in Section C405.2.8.1.EXCEPTION:Excep…

C405.2.1 Occupant sensor controls. Occupant sensor controls shall be installed to control luminaires in the space types listed in Table C405.2.1, and shall comply with the requirements listed in the table.EXCEPTIONS:1. Corridors in manufacturing facilities. 2. General lighting an…

C405.2.2 Time switch controls. Each area of the building that is not provided with occupant sensor controls complying with Section C405.2.1.1 shall be provided with time switch controls complying with Section C405.2.2.1.EXCEPTIONS:1. Luminaires which are required to have specific…

C405.2.3 Manual controls. All lighting shall have manual controls complying with the following:1. They shall be in a location with ready access to occupants.2. They shall be located where the controlled lights are visible, or shall identify the area served by the lights and indic…

C405.2.4 Light-reduction controls. Where not provided with occupant sensor controls complying with Section C405.2.1.1, general lighting shall be provided with light-reduction controls complying with Section C405.2.4.1.EXCEPTIONS:1. Luminaires controlled by daylight responsive con…

C405.2.5 Daylight responsive controls.Daylight responsive controls complying with Section C405.2.5.1 shall be provided to control the general lighting within daylight zones in the following spaces:1. Spaces with a total of more than 75 watts of general lighting within primary sid…

C405.2.6 Additional lighting controls. Specific application lighting shall be provided with controls, in addition to controls required by other sections, for the following:1. The following lighting shall be controlled by an occupant sensor complying with Section C405.2.1.1 or a t…

C405.2.7 Area controls. The maximum lighting power that may be controlled from a single switch or automatic control device shall not exceed that which is provided by a 20 ampere circuit loaded to not more than 80 percent. A master control may be installed provided the individual …

C405.2.8 Advanced lighting controls. Any contiguous open office area larger than 5,000 square feet shall have its general lighting controlled by either:1. Luminaire-level lighting controls (LLLC) conforming to the requirements of Section C405.2.8.1.2. Networked lighting control (…

C405.2.9 Exterior lighting controls. Exterior lighting systems shall be provided with controls that comply with Sections C405.2.9.1 through C405.2.9.4.EXCEPTIONS:1. Lighting for covered vehicle entrances or exits from buildings or parking structures where required for safety, sec…

C405.2.10 Parking garage lighting control. Parking garage lighting shall be controlled by an occupant sensor complying with Section C405.2.1.1 or a time-switch control complying with Section C405.2.2.1. Additional lighting controls shall be provided as follows:1. Lighting power o…

C405.3 Lighting for plant growth and maintenance. All permanently installed luminaires used for plant growth and maintenance shall have a photosynthetic photon efficacy measured at the lamp for luminaires with serviceable or removable lamps or at the luminaire for integrated, non…

[Statutory Authority: RCW 19.27A.020, 19.27A.025, 19.27A.160 and chapter 19.27 RCW. WSR 19-24-040, § 51-11C-40504, filed 11/26/19, effective 7/1/20. Statutory Authority: RCW 19.27A.025, 19.27A.160, and 19.27.074. WSR 16-03-072, § 51-11C-40504, filed 1/19/16, effective 7/1/16. Sta…

C405.4 Interior lighting power requirements. A building complies with this section if its total connected interior lighting power calculated under Section C405.4.1 is no greater than the interior lighting power allowance calculated under Section C405.4.2.[Statutory Authority: RCW…

C405.4.1 Total connected interior lighting power. The total connected interior lighting power shall be determined in accordance with Equation 4-13.TCLP = [LVL + BLL + TRK + POE + Other](Equation 4-13)Where:TCLP = Total connected lighting power (watts).LVL = For luminaires with la…

C405.4.2 Interior lighting power allowance. The total interior lighting power allowance (watts) for an entire building shall be determined according to Table C405.4.2(1) using the Building Area Method, or Table C405.4.2(2) using the Space-by-Space Method. The interior lighting po…

Table C405.4.2(1)Interior Lighting Power Allowances—Building Area MethodBuilding Area TypeLPD(w/ft2)Automotive facility0.64Convention center0.64Court house0.79Dining: Bar lounge/leisure0.79Dining: Cafeteria/fast food0.72Dining: Family0.71Dormitory0.46Exercise center0.67Fire stati…

Table C405.4.2(2)Interior Lighting Power Allowances—Space-by-Space MethodCommon Space-by-Space Typesa,jLPD (w/ft2)Atrium - Less than 20 feet in height0.39Atrium - 20 to 40 feet in height0.48Atrium - Above 40 feet in height0.60Audience/seating area - Permanenti In an auditorium0.6…

C405.5 Exterior lighting power requirements. The total connected exterior lighting power calculated in accordance with Section C405.5.2 shall not be greater than the exterior lighting power allowance calculated in accordance with Section C405.5.3.[Statutory Authority: RCW 19.27A.…

C405.5.1 Exterior building grounds lighting. All exterior building grounds luminaires that operate at greater than 25 watts shall have a minimum efficacy of 100 lumens per watt.EXCEPTIONS:1. Luminaires controlled by a motion sensor. 2. Luminaires that qualify for one of the excep…

C405.5.2 Total connected exterior building lighting power. The total exterior connected lighting power shall be the total maximum rated wattage of all exterior lighting that is powered through the energy service for the building.EXCEPTION:Lighting used for the following applicati…

Table C405.5.3(1)Exterior Lighting ZonesLighting ZoneDescription1Developed areas of national parks, state parks, forest land, and rural areas2Areas predominantly consisting of residential zoning, neighborhood business districts, light industrial with limited nighttime use and res…

Table C405.5.3(2)Lighting Power Allowances for Building Exteriors Lighting Zones Zone 1Zone 2Zone 3Zone 4Base Site Allowance160 W280 W400 W560 WUncovered Parking AreasParking areas and drives0.015 W/ft20.026 W/ft20.037 W/ft20.052 W/ft2Building GroundsWalkways and ramps less than …

C405.6 Electrical transformers. Low-voltage dry-type distribution electric transformers shall meet the minimum efficiency requirements of Table C405.6 as tested and rated in accordance with the test procedure listed in DOE 10 C.F.R. 431. The efficiency shall be verified through c…

C405.8 Electric motor efficiency. All electric motors, fractional or otherwise, shall meet the minimum efficiency requirements of Tables C405.8(1) through C405.8(4) when tested and rated in accordance with DOE 10 C.F.R. 431. The efficiency shall be verified through certification …

C405.9 Vertical and horizontal transportation systems and equipment. Vertical and horizontal transportation systems and equipment shall comply with this section.C405.9.1 Elevator cabs. For the luminaires in each elevator cab, not including signals and displays, the sum of the lum…