Building Codes
BIAW monitors codes and regulations, provides comments on pending rules and regulations, and provides resources and information to members.
Codes & Regulations
Every three years, new model construction codes are published through the International Code Council (ICC). The State Building Code Council (SBCC), with the assistance of their Technical Advisory Groups (TAGs), adopts the amendments.
The SBCC has delayed implementation of the 2021 Residential Code, Energy Code and WUI Code until Oct. 29, 2023
2018 Residential Construction Code in Effect February 1, 2021
The SBCC has adopted the 2018 editions of the International Building Code (IBC), International Residential Code (IRC), International Fire Code (IFC), International Mechanical Code (IMC) and Uniform Plumbing Code (UPC) with state amendments; and the 2018 Washington State Energy Code (WSEC). The 2018 code becomes effective February 1, 2021.
- 2018 International Building Code State amendments insert pages
- 2018 International Fire Code State amendments Insert pages
- 2018 International Mechanical Code State amendments insert pages
- 2018 International Residential Code State amendments insert pages
- Uniform Plumbing Code State amendments insert pages
Washington State Energy Code Updates
The 2018 Washington State Energy Code, which is actually a combination of the 2018 International Energy Conservation Code (IECC) and the 2015 Washington State Energy Code (WSEC), has now been divided into commercial and residential provisions – both are available to download below:
Based on the 2018 IECC, “Residential” includes one- and two-family dwellings, townhouses and group R-2 and R-3 buildings three stories or less. “Commercial” includes all buildings not covered under “residential.”
Below are highlights of the revisions of the significant changes to the WSEC:
Energy Code Changes
Per RCW 19.27, permitted construction must achieve 70% reduction in annual net energy consumption by 2031 using 2006 Wa. State Energy Code as the base level. Continued incremental changes have been made this code cycle for fuel source selection, envelope air leakage control, ventilation system effectiveness, HVAC efficiencies, hot water generation equipment, renewable electric energy and lighting equipment.
Changes to Energy Code Credits
A dynamic shift takes place in the 2018 WSEC. “Carbon emissions equalization” between heating source fuels incentivizes high-efficiency heat pump HVAC equipment and renewable energy generation (wind/solar). Penalties are incorporated for combustion-fuel and electric-resistance equipment.
Required additional “credits” now includes R-2 occupancies. Dwellings:
- Less than 1,500 sq. ft. require 3 credits (previously 1.5)
- 1,501-4,999 sq. ft. require 6 credits (previously 3.5)
- 5,000+ sq. ft. require 7 credits (previously 4.50)
R-2 dwellings require 4.5 credits (previously 2.5) and residential additions less than 500 sq. ft. require 1.5 credits (previously 0.5).
2018 WSEC introduces a new appliance package credit option. Installed appliances must be Energy Star rated and include a ductless clothes dryer without vent ducting or exterior vent caps installed in the building.
New Simulated Performance Metrics
Building designs using the Simulated Performance Alternative method (comparing a standard reference design to a proposed design) now must show reduced annual energy consumption based on “carbon emissions” of the fuels and energy use in the proposed building design.
Building Code Planning Changes
The 2018 IRC includes updates to climate, geographic and seismic design criteria. Building departments must now provide “Manual-J” local design criteria for heating/cooling calculations.
Two-Family Dwelling Separation
2018 IRC references the 2018 IBC (non-residential construction), incorporating tried & true methods for constructing fire-resistance wall assemblies used in commercial construction.The code permits a half-hour fire-resistance wall rating in buildings equipped with an automatic fire sprinkler system.
Updated Safety Glazing and Stairs
The code modifies requirements for safety glazing adjacent to doors as well as emergency escape and rescue openings. It also clarifies handrail projections on stairs and increases new standards for max stair rise between landings, recognizing use of taller engineered floor joists for longer open spans and space for HVAC ducting.
Heat, Smoke & CO Sensors
The codes now requires “heat-detection” devices in garages and updates placement locations for smoke detectors near bathrooms. Updated carbon monoxide alarm standards allow builders to utilize new wireless sensor technology in their projects.
Photovoltaic/Solar Energy Systems
Newly defined pathway clearances around PV roof panel placements provide firefighter access and clearance for emergency escape/rescue openings.
Two-Family Dwelling Separation
2018 IRC references the 2018 IBC (non-residential construction), incorporating tried & true methods for constructing fire-resistance wall assemblies used in commercial construction.The code permits a half-hour fire-resistance wall rating in buildings equipped with an automatic fire sprinkler system.
Mezzanine Areas, Habitable Attics and Sleeping Lofts
Mezzanines can now be increased to half the area of the room containing the mezzanine if a sprinkler system is added. Definition of “habitable attic” has been changed to “a finished or unfinished habitable space within an attic.” The Washington state amendment added this space (with exceptions) to be considered a “story above grade plane.” Amendments address new standards for sleeping lofts in “condensed dwelling units” to include limits for floor area, access/egress requirements, headroom, tread/riser sizing, handrails and landing dimensions.
Family Homes and Radon Protection
The SBCC added a section for Adult Family Homes specifying grab bar placement, handrail/riser dimensions and door lock installation regulations. An SBCC amendment requires radon control provisions (Appendix F) applicable to buildings constructed in high radon potential counties (Clark, Ferry, Okanogan, Pend Oreille, Skamania, Spokane and Stevens). Per the amendment, unvented crawl spaces will not be allowed for these counties.
Footing Sizes and Deck Framing
A state amendment provides alternative footing size graphs for light-frame construction (per snow load). The state amendment provides new design tables for a required increase to 2018 IRC live loads, materials, posts, joists and lateral support for decks.
Stud Height, Lateral Support for Headers and Water-Resistive Barriers
The 2018 IRC provides updated design tables for taller stud height, lateral support for headers, water resistive barrier installation criteria, roof framing and chimney insulation barriers.
Mechanical and Gas Code Changes
Clearance requirements around furnaces are now deferring to manufacturers’ specifications. Makeup air for high-volume kitchen exhaust systems is clarified. PEX tubing support placement recognizes larger diameter supply piping. Gas-fired clothes-dryers may now be installed in bathrooms where permanent openings communicate with other permitted spaces. The 2018 IRC appendices include updates for tiny houses, straw-clay construction, straw-bale construction, solar-ready zones and fire sprinklers.
Wildland-Urban Interface Code
The Legislature directed the Washington State Building Code Council (SBCC) to adopt specific portions of the 2018 International Wildland-Urban Interface (WUI) code. Instead, the SBCC chose to adopt the entire 2021 WUI code, which will have a significant impact on proposed construction projects—both in actual costs and planning time.
The WUI code is a hybrid between land-use and building codes, designed to protect structures from wildfires by requiring builders to use fire-resistive building materials and to reduce vegetation near all structures.
The SBCC has delayed implementation of all the new codes to Oct. 29, 2023. At that time, the WUI codes will apply to new projects not already vested. Vested projects include those with complete building permit, shot plat or subdivision applications already submitted. They also include projects with certain subdivision approvals and development agreements.
Am I in the WUI?
Per RCW 19.27, permitted construction must achieve 70% reduction in annual net energy consumption by 2031 using 2006 Wa. State Energy Code as the base level. Continued incremental changes have been made this code cycle for fuel source selection, envelope air leakage control, ventilation system effectiveness, HVAC efficiencies, hot water generation equipment, renewable electric energy and lighting equipment.
What is defensible space? Is there a minimum setback?
Per RCW 19.27, permitted construction must achieve 70% reduction in annual net energy consumption by 2031 using 2006 Wa. State Energy Code as the base level. Continued incremental changes have been made this code cycle for fuel source selection, envelope air leakage control, ventilation system effectiveness, HVAC efficiencies, hot water generation equipment, renewable electric energy and lighting equipment.
Is the WUI being adopted statewide on October 29?
Per RCW 19.27, permitted construction must achieve 70% reduction in annual net energy consumption by 2031 using 2006 Wa. State Energy Code as the base level. Continued incremental changes have been made this code cycle for fuel source selection, envelope air leakage control, ventilation system effectiveness, HVAC efficiencies, hot water generation equipment, renewable electric energy and lighting equipment.
Is my project required to comply?
Per RCW 19.27, permitted construction must achieve 70% reduction in annual net energy consumption by 2031 using 2006 Wa. State Energy Code as the base level. Continued incremental changes have been made this code cycle for fuel source selection, envelope air leakage control, ventilation system effectiveness, HVAC efficiencies, hot water generation equipment, renewable electric energy and lighting equipment.
What if my project is on a boundary line?
Per RCW 19.27, permitted construction must achieve 70% reduction in annual net energy consumption by 2031 using 2006 Wa. State Energy Code as the base level. Continued incremental changes have been made this code cycle for fuel source selection, envelope air leakage control, ventilation system effectiveness, HVAC efficiencies, hot water generation equipment, renewable electric energy and lighting equipment.
What’s subject to the WUI?
Per RCW 19.27, permitted construction must achieve 70% reduction in annual net energy consumption by 2031 using 2006 Wa. State Energy Code as the base level. Continued incremental changes have been made this code cycle for fuel source selection, envelope air leakage control, ventilation system effectiveness, HVAC efficiencies, hot water generation equipment, renewable electric energy and lighting equipment.
What’s a Finding of Fact? Why Would I Need One?
Per RCW 19.27, permitted construction must achieve 70% reduction in annual net energy consumption by 2031 using 2006 Wa. State Energy Code as the base level. Continued incremental changes have been made this code cycle for fuel source selection, envelope air leakage control, ventilation system effectiveness, HVAC efficiencies, hot water generation equipment, renewable electric energy and lighting equipment.
BIAW’s 2018 Code Changes
If you missed the chance to attend BIAW’s 2018 Codes class, you can download and view the 2018 Significant Code Changes PowerPoint presentation.
Download
Sign Up for BIAW Code Classes
The Building Industry Association of Washington is providing a more in-depth discussion of these updates in (on-line) codes training classes. The BIAW instructors for the “2018 Significant Code Changes” classes are industry professionals, providing insight and examples of how builders can implement these code changes in their projects.
View Classes
Questions?
If you have any questions regarding residential building codes and regulations, please contact Policy & Research Manager Andrea Smith.
Additional Resources
International Code Council
You can purchase I-Codes books from the International Code Council. If you are an ICC member, contact Andrea Smith to receive the member discount.
WABO Bookstore
Purchase building code books from the Washington Association of Building Officials online bookstore.
Construction Liens: What You Should Know About Contracts
Prepared L&I document for general contractors that must accompany the notice to the customer.
031
Statutory notice requirements and contract language for subcontractors and suppliers.
BIAW’s 2018 Code Changes
If you missed the chance to attend BIAW’s 2018 Codes class, you can download and view the 2018 Significant Code Changes PowerPoint presentation.
Download
Sign Up for BIAW Code Classes
The Building Industry Association of Washington is providing a more in-depth discussion of these updates in (on-line) codes training classes. The BIAW instructors for the “2018 Significant Code Changes” classes are industry professionals, providing insight and examples of how builders can implement these code changes in their projects.
View Classes
Questions?
If you have any questions regarding residential building codes and regulations, please contact Policy & Research Manager Andrea Smith.