You don't have to bring your whole house up to new-home energy rules when you add on or remodel. But the new or changed parts usually have to meet the current Washington State Energy Code – Residential (WSEC-R), and bigger additions may need energy credits.
Additions: new space meets current insulation and window requirements, and may need energy credits.
Remodels: opened walls, ceilings, and floors are insulated to current levels, and replacement windows meet current performance.
Garage or basement conversions: treated a lot like new construction for the converted area.
Testing: some additions need a blower door air leakage test before final. WA Blower Door does blower door air leak testing only.
Sort out what energy code requirements apply to your project
Put energy code notes on the drawings
Fill out the energy code forms
Answer energy code corrections from the reviewer
Questions about energy code on your project? Call 253-799-0606 or email office@dowengineeringpllc.com, or use the Contact Us button.
Build Sherpas is a trade name of Dow Engineering PLLC · 16202 64th St E Ste 117, Sumner, WA 98390
Copyright © 2026 Build Sherpas. Part of the Dow Engineering family in Sumner, WA: Dow Engineering PLLC (structural and civil engineering), Build Sherpas (plans and permits), WA Blower Door (energy code testing). 16202 64th St E Ste 117, Sumner, WA 98390 · (253) 799-0606 · office@buildsherpas.com
Areas we serve: Sumner · Puyallup · Tacoma · Bonney Lake · Auburn
ADU plans: Tacoma · Puyallup · Garage conversions
A Dow Engineering PLLC Company