Kirkland is one of the best cities on the Eastside for ADU development — large lots, strong rental demand, a faster permit process than Seattle, and a location at the heart of the tech employment corridor. Piper Cole Architects is headquartered in Kirkland and has permitted more ADUs here than anywhere else in our service area.
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Kirkland ADU Types and Rules (2026)
- DADU (backyard cottage): Up to 1,000 sq ft, 18 ft max height, 5 ft rear and side setbacks
- Attached ADU: Basement conversion, garage conversion, or addition — no separate size limit beyond overall lot coverage
- Both types: Allowed on one lot simultaneously in most Kirkland residential zones
Kirkland ADU Permit Process
City of Kirkland ADU permits typically process in 4-8 weeks — one of the faster jurisdictions on the Eastside. Kirkland uses an online permit portal. Piper Cole Architects has established relationships with Kirkland permit staff and submits complete, code-compliant packages that minimize correction cycles.
ADU Rental Income in Kirkland (2026)
- Studio ADU: $1,500-$2,000/month
- 1-bedroom ADU: $2,000-$2,700/month
- 2-bedroom ADU: $2,600-$3,400/month
ADU Project Costs in Kirkland
- Garage conversion ADU: $90,000-$175,000
- Detached backyard cottage: $260,000-$450,000
- Architect fees: $15,000-$32,000
Ready to start? See our ADU service or get a free consultation. We are in Kirkland — call 425-753-6452.
Ready to talk about your project?
Piper Cole Architects has designed 800+ Eastside projects since 2000. Get a free, no-pressure consultation with David Meade, AIA, NCARB.