WSEC Amendments

In the WAC, refer to 51-11C for the most recent provision language for the 2015 WSEC for Commercial. To view official SBCC documents for proposed and permanent rule amendments, select “Agency filings affecting this section” under each provision. Summary information about permanent rule amendments, including the date the amendments go into effect, are available on this webpage. Enter a general WSEC topic to view amendments affecting provisions related to your topic of interest.

Visit the Washington Administrative Code (WAC) - Title 51

Code Section Section Title Amendment Summary Agency Filing Effective Date
C103.6.2 Manuals Requires O&M manuals for each component, device, piece of equipment, and system that is governed by the WSEC. WSR 16-24-070 2017-05-01
C103.6.2 Manuals Requires a narrative for each system that describes how it is intended to operate, including recommended setpoints. WSR 16-24-070 2017-05-01
C104.2.4 Mechanical inspections Requires inspection of installed duct and piping system insulation and corresponding R-value. WSR 16-24-070 2017-05-01
C202.12--L Luminaire level lighting control Requires each luminaire in a lighting system to have embedded lighting control logic, occupancy and ambient light sensors, local or central wireless networking capabilities and local override switching capability. WSR 16-24-070 2017-05-01
C202.3--C Certified commissioning professional Defined as an individual certified by an ANSI/ISO/IEC 17024:2012 accredited organization, or a licensed professional engineer is WA State. WSR 16-24-070 2017-05-01
C202.4--D Door, Nonswinging Defined as a roll-up, tilt-up, metal coiling or sliding doors, access hatches, and all other doors that are not swinging. WSR 16-24-070 2017-05-01
C202.4--D Door, Swinging Defined as doors that are hinged on one side and revolving doors. WSR 16-24-070 2017-05-01
C401.2.1 Application to existing buildings For existing buildings, requires compliance with all applicable provisions in Chapter 5 in addition to all applicable provisions in Chapter 4. WSR 16-24-070 2017-05-01
C402.1 General (Prescriptive) Identifies C402.1.5 component performance as an allowed compliance alternative to prescriptive compliance for fenestration U-factors and SHGCs per C402.4. WSR 16-24-070 2017-05-01
C402.1.1.1 Semi-heated buildings and spaces Requires semi-heated buildings, or portions thereof, to comply with the same requirements as that of conditioned spaces, except as modified by this section. WSR 16-24-070 2017-05-01
C402.1.3 Opaque Thermal Envelope Insulation Component Minimum Requirements, R-value Method Requires a thermal spacer block with minimum thickness of 1/2-inch and minimum R-value of R-3.5 for metal building roof assemblies. WSR 16-24-070 2017-05-01
C402.1.3 Opaque Thermal Envelope Insulation Component Minimum Requirements, R-value Method Requires below-grade heated slab floors to be insulated to the same level as heated slab-on-grade floors. WSR 16-24-070 2017-05-01
C402.1.4 Opaque Thermal Envelope Requirements, U-factor Method Requires below-grade heated slab floors to be insulated to the same level as heated slab-on-grade floors. WSR 16-24-070 2017-05-01
C402.1.4.1 Thermal resistance of cold-formed steel stud walls Added stud to title WSR 16-24-070 2017-05-01
C402.1.5 Component performance alternative Corrections to variable definitions in equation. Includes 40% maximum allowed prescriptive verticial fenestration allowance for projects that comply with C402.4.1.4 High performance mechanical systems (DOAS). Note section reference typo (C402.1.4.1 is supposed to be C402.4.1.4). WSR 16-24-070 2017-05-01
C402.1.5 Component performance alternative Clarifications and corrected language and section references in Equation 4-2 for the component performance UA trade-off calculation, including target area adjustment. WSR 19-02-089 2019-07-01
C402.1.5.2 SHGC rate calculations Corrections to variable definitions in equation. WSR 16-24-070 2017-05-01
C402.1.5.2 SHGC rate calculations Clarifications and corrected language in Equation 4-3 for the component performance SHGC x A trade-off calculation for vertical fenestration and skylights. Clarifies that target area adjustment is allowed for SHGC x A. WSR 19-02-089 2019-07-01
C402.2 Specific building thermal envelope insulation requirements (Prescriptive) Clarifies that alternate levels of insulation in an assembly are allowed so long as the U-factor of the assembly is less than or equal to the U-factor of the respective compliance path, which includes the UA trade-off method. WSR 16-24-070 2017-05-01
C402.4.2 Minimum skylight fenestration area WSR 16-24-070 2017-05-01
C402.4.4 Doors For doors defined as fenestration, the door area shall include the frame. WSR 16-24-070 2017-05-01
C403.2.4.1 Thermostatic controls Clarifies Exception 2 that allows adjacent interior and perimeter zones to be in opposing modes provided the thermostatic deadbands of the adjacent zones are coordinated so that cooling in the interior zone does not occur while the perimeter zone is in heating until the interior zone temperature is 5¼F higher than the perimeter zone temperature. WSR 16-24-070 2017-05-01
C404.6 Insulation of (SWH) piping For service water heating systems, this amendment adds an exception clarifying that the final pipe run to a plumbing fixture is not required to be insulated provided the pipe run is not part of the heated-water circulation system. WSR 19-02-089 2019-07-01
C405.11 Electrical power and lighting systems commissioning and completion requirements Pointer to C408 Commissioning section for all electrical and lighting systems governed by C405. WSR 16-24-070 2017-05-01
C406.5 On-site renewable energy Clarifies that the required efficiency rating is based on the annual energy production of the system per square foot of conditioned floor area (Table C406.5 kBtu/year or kWh/year. WSR 16-24-070 2017-05-01
C406.8 Enhanced envelope performance option Language amended to be consistent with amendments to C402.1.5 Component performance alternative. WSR 19-02-089 2019-07-01
C407.5.1(1) Specifications for the Standard Reference and Proposed Designs In the standard reference design, cooling systems shall be modeled with economizer in accordance with Section C403.3. WSR 16-24-070 2017-05-01
C407.5.1(1) Specifications for the Standard Reference and Proposed Designs Corrections to CFM variable definition in equation. DOAS fan power no longer required to be calculated separately from the brakehorsepower allowance. WSR 16-24-070 2017-05-01
C407.5.1(2) HVAC Systems Map for Buildings Goverened by Section C403.6 (DOAS) Replaced information with corrected table. Consolidated standard reference deisgn HVAC system type to one list. WSR 16-24-070 2017-05-01
C408.1 Commissioning - General Adds C410 refrigeration systems to list of systems required to be commissioned. WSR 16-24-070 2017-05-01
C408.2 Mechanical and refrigeration systems commissioning Adds C410 refrigeration systems to list of systems required to be commissioned. WSR 16-24-070 2017-05-01
C410.1 Refrigeration systems - General Requires compliance with all applicable provisions in C402. This includes all building envelope provisions where specific requirements are not stated in C410, such as slab-on grade insulation and air barrier requirements. Where similar requirements are defined in both sections, provisions in C410 supercede the provisions in C402 for refrigerated spaces. WSR 16-24-070 2017-05-01
C410.1 Refrigeration systems - General Allows the envelope component performance compliance path for refrigerated spaces, with prior approval by the jurisdiction. WSR 16-24-070 2017-05-01
C410.2 Walk-in coolers, walk-in freezers, refrigerated warehouse coolers and refrigerated warehouse freezers This section applies to refrigerated warehouse coolers and freezers, and all walk-in coolers and freezers including site assembled, site constructed and prefabricated. WSR 16-24-070 2017-05-01
C410.2 Walk-in coolers, walk-in freezers, refrigerated warehouse coolers and refrigerated warehouse freezers Clarifies that automatic door-closers shall fully close walk-in doors. WSR 16-24-070 2017-05-01
C410.2 Walk-in coolers, walk-in freezers, refrigerated warehouse coolers and refrigerated warehouse freezers Clarifies that windows in reach-in or walk-in doors shall be provided with triple pane glazing in freezers, and double or triple pane glazing in coolers, that have either a heat-reflective coating or the interstitial space between the glass is filled with an inert gas. WSR 16-24-070 2017-05-01
C410.2 Walk-in coolers, walk-in freezers, refrigerated warehouse coolers and refrigerated warehouse freezers Requires light source with efficacy not less than 40 lumens/watt including ballast losses, or automatic occupancy controls that shut off lights within 15 minutes of space being unoccupied. WSR 16-24-070 2017-05-01
C410.3 Refrigeration systems Requires refrigeration systems with remote condensers and to comply with C403.5.3 Condenser heat recovery. WSR 16-24-070 2017-05-01
C503.2 Change in space conditioning Language amended to be consistent with amendments to C402.1.5 Component performance alternative. WSR 19-02-089 2019-07-01
C503.6 Lighting and motors Where less than 50% of installed exterior lighting wattage is altered, the resulting exterior lighting wattage shall be equal to or less than the wattage prior to the alteration. WSR 16-24-070 2017-05-01
C505.1 Change in occupancy or use - General Language amended to be consistent with amendments to C402.1.5 Component performance alternative. WSR 19-02-089 2019-07-01