Grant County Washington Energy Code Compliance
WSEC-R 2021 compliance information for builders and contractors in Grant County.
Code environment
Climate Zone
CZ5
Eastern Washington — stricter insulation and air-sealing minimums apply.
Wall min R-20 or R-13+5ci · Ceiling min R-49 · Window max U-0.28 (WAC 51-11R-40202)
Radon Zone
Zone 2
Moderate radon potential — radon-resistant construction recommended but not mandated by state code.
Learn more →County building department
The county building department handles permits for unincorporated areas. Cities within the county may have their own permit offices — see below.
Authority Having Jurisdiction (AHJ)
Grant County Development Services
- Phone
- (509) 754-2011
- Address
- 264 West Division Ave, Ephrata, WA 98823
- Hours
- M-F 8am-5pm
Last verified: 2026-04-19
Cities with their own building department
These cities have an independent permit office. If your project is inside city limits, contact the city — not the county — for permits.
Ready to check your compliance?
Answer a few questions about your project and get a complete R406 credit summary you can submit with your permit application.
Start your WSEC compliance check →Typical project costs in Grant County
Coming soon as we gather receipt data from local contractors.
Information on this page may be out of date. Report outdated info →