Fences and retaining walls are among the most common projects Seattle homeowners undertake, and one of the most common sources of confusion about permit requirements. Here is a clear guide.
Fences
No permit required: Fences up to 8 feet tall in most residential zones, when not in the front yard setback area.
Permit required: Fences over 8 feet, fences in the shoreline jurisdiction, and fences on properties with critical area designations.
Front yard fences: In most Seattle residential zones, front yard fences are limited to 4 feet. Fences along side yards in the front setback are typically limited to 6 feet on the street-facing elevation.
Retaining Walls
No permit required: Retaining walls under 4 feet of exposed height (measured from the bottom of footing to the top of wall).
Permit required: Retaining walls 4 feet or over. Walls over 4 feet require structural design by a licensed engineer.
Critical consideration: Multiple tiered walls of less than 4 feet each, placed to avoid permits, are often not allowed, the cumulative height is evaluated. Check with SDCI before designing a tiered wall system.
Planning a project?
Working out what your lot will allow, and what it will cost?
Send David the address and a few lines about what you want. The first feasibility check is free and usually takes about a day: what the site and the code are likely to allow, and what to check first.
Architect since 1996, member of the AIA and NCARB. Three Masonry Excellence Awards for commercial projects; the Carr residence was featured in Above The Lake and Lux magazines.
When You Need a Structural Engineer
Retaining walls over 4 feet, walls holding back saturated soil, walls adjacent to structures or property lines, and walls in areas with challenging soil conditions all require structural engineering. An architect coordinates this engineer as part of the permit process.
Seattle Setback Rules for Walls
Retaining walls must comply with property setback requirements, they cannot encroach into required setbacks without a variance. This is frequently overlooked and discovered during permit review.
Piper Cole Architects designs and permits retaining walls and site improvements throughout Seattle. free feasibility check, call 425-753-6452.
Authoritative sources
Regulatory requirements referenced in this guide are set by the official agencies below. Rules change, always confirm current requirements with the source:
