Renton, WA Zoning Overlays & Bonuses: Density Bonus Law (2026)

RMC 4-9-065 lets a developer request a density bonus for on-site or off-site affordable housing, assisted living facilities, cottage house developments, or commercial-to-residential conversions built within an existing building envelope, but density bonuses are unavailable to any project that also requests a variance. In R-14 and RMF, affordable housing projects can gain up to 30% above the zone's maximum net density set in RMC 4-2-110A; the same 30% cap applies to CV, UC, CD, CO and COR zones referencing RMC 4-2-120A and 4-2-120B. Assisted living facilities can reach up to 18 dwelling units per net acre in R-1, R-10 and R-14, or up to 50% above maximum net density in RMF, CV, UC, CD, CO and COR.

5 times the number of lots identified in the pro forma subdivision plan. For every two dwelling units built beyond the baseline maximum density, at least one unit must be reserved as affordable, defined as owner-occupancy housing serving households at or below 80% of area median income or rental housing at or below 50% of AMI, calculated from HUD's Seattle-Bellevue Metro Fair Market Rent Area figures. On-site affordable projects must build at least two affordable units, keep them affordable for 50 years under a recorded agreement with the King County Recorder's Office, and file annual (rental) or per-sale (ownership) compliance reports with the city Administrator.

Review is concurrent with the primary land use permit; the Community and Economic Development Administrator decides compliance unless the underlying permit requires Hearing Examiner review, and a density bonus request is submitted with the primary application under RMC 4-8-120.