Bellevue's ADU pathway in 2026
Bellevue's Land Use Code post-HB 1337: what is now permitted by right, what still requires conditional approval, and how design review actually works.
What the LUC update did
Bellevue's 2024 Land Use Code amendments brought the city into HB 1337 compliance. Two ADUs are now permitted on any R-1 through R-7.5 single-family parcel. DADUs up to 1,000 sqft of gross floor area, 25-foot height on flat roofs, 30 feet on pitched, with reduced rear and side setbacks in the back half of the lot.
Owner-occupancy was struck. Off-street parking is not required within a half-mile of a frequent-transit corridor; elsewhere the requirement is one stall per ADU.
Sources:City of BellevueMunicipal Research and Services Center of Washington
What still needs conditional review
Critical-area parcels — steep slopes over 40%, geological hazards, wetlands, streams, or their buffers — still require a separate critical-area determination, which adds 6–10 weeks to the schedule and frequently triggers a geotech report and a habitat-management plan.
Through-lots (parcels with frontage on two parallel streets) carry additional design-review thresholds in some Bellevue neighborhoods to manage streetscape impact. Wilburton, Bridle Trails, and parts of Somerset see this most often.
Permit timeline reality
On a clean lot with no critical-area overlay, Bellevue is issuing DADU permits in 14–20 weeks from intake. Plan-check fees run $5,500–$8,200 for a typical 800-sqft DADU. School-impact fees are paid to the Bellevue School District at the time of permit issuance and are in the $5,000–$7,500 range.
The single longest item on most Bellevue projects is the side-sewer connection design coordinated with Bellevue Utilities — budget 4–6 weeks for review and pay close attention to depth and slope to avoid a request for a private lift station.
Resale and rental context
Median rent for a 1-bedroom Bellevue ADU sits in the $2,500–$3,000 range. Resale uplift from a permitted DADU has clocked 1.4× to 1.7× of project cost in recent comparable sales we have tracked across Bellevue's R-5 zones — meaningfully higher than the Seattle citywide average, driven by the city's land scarcity and the depth of corporate-tenant demand.
