Seattle, WA Noise Ordinances: Construction Hours (2026)
Construction hours in Seattle, WA, sometimes called construction noise rules or contractor work-hour ordinances, set when contractors can run power tools, hammers, and heavy equipment.
Key Facts
- Code
- SMC 25.08.425
- Daytime cap
- 80 dBA at line
- Permitted hours
- 7am-10pm weekdays
- Variance authority
- SDCI Director
- Impact tools
- Mitigation required
Summary
Seattle SMC 25.08 limits construction equipment to 80 dBA measured at the receiving property line, with maximum-noise exemptions during permitted weekday daytime hours. Impact equipment like jackhammers requires noise-reduction measures.
Construction and Maintenance Hours — In general, you can do construction work: 7:00 a.m. - 10:00 p.m., weekdays; 9:00 a.m. - 10:00 p.m., weekends and legal holidays. If your construction and maintenance activities are within multifamily and neighborhood commercial zones (Lowrise, Midrise, Highrise, Residential Commercial and Neighborhood Commercial) you can work: 7:00 a.m. - 7:00 p.m., weekdays; 9:00 a.m. - 7:00 p.m., weekends and legal holidays. Your impact construction work (pile driving, jackhammers, etc.) is limited to: 8:00 a.m. - 5:00 p.m., weekdays; 9:00 a.m. - 5:00 p.m., weekends and legal holidays. Legal holidays are New Year's Day, Memorial Day, Independence Day, Labor Day, Thanksgiving Day, Day after Thanksgiving, and Christmas Day.
Full Breakdown
Seattle's Noise Ordinance, SMC 25.08.425, exempts construction during permitted hours (7 a.m. to 10 p.m. weekdays, 9 a.m. to 10 p.m. weekends) but caps overall sound at 80 dBA measured at the adjacent property line in residential zones. Outside those hours, construction noise must meet baseline residential limits of 55 dBA day / 45 dBA night absent a Noise Variance from the Director of Construction and Inspections. Impact equipment (pile drivers, jackhammers, hoe rams) must use mufflers, shrouds, or other mitigation. Major projects often obtain Major Public Project Construction Noise Variances allowing limited night work with monitoring and community notification. Seattle Department of Construction and Inspections enforces complaints; SPD handles after-hours violations. Sea-Tac airport-adjacent projects have additional FAA noise considerations.
Violations & Fines
First violation: warning. Subsequent: $250-$500 per day. Repeat violator: criminal misdemeanor up to $5,000. Stop-work order possible. SDCI variance revocation for noncompliance.
Frequently Asked Questions
Can my neighbor jackhammer at 6 a.m.?
How is construction noise measured?
Sources & Official References
Other rules in Seattle
How Seattle compares: Cities with the Strictest Construction Hours·Compare Seattle to another location·View the Washington noise ordinances overview
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Construction Hours in Nearby Cities
How other cities in King County handle construction hours.