Pierce County, WA Zoning Overlays & Bonuses: Density Bonus Law (2026)
Key Facts
- Governing chapter
- PCC 18A.65
- Single-family bonus cap
- 133% of max density
- Multi-family/mixed-use cap
- 120% of max density
- Affordability duration
- 50 years, recorded covenant
- Excluded zone
- Residential Resource (RR)
- Early conversion payment
- 20% of net sale proceeds
Summary
Pierce County lets developers exceed zoning's maximum density if they build low-income affordable units under PCC 18A.65. Single-family zones can reach 133% of the base density (a 6 du/acre zone tops out at 7.98 du/acre) and multi-family or mixed-use zones can reach 120% of the base density.
1. The density within all zones may exceed the maximum density provisions called out in Title 18A PCC, Pierce County Development Regulations – Zoning, for the entire site (including that portion not accommodating low-income housing). ... Density Limitation: Single-family residential zones = 133% x maximum density (Max. Density = 6 x 1.33 = 7.98 du/a) Multi-family/Mixed Use zones that allow for Multi-Family development = 120% x maximum density (CC Max. Density = 25 x 1.20 = 30 du/acre)
Official source re-checked September 8, 2026: no newer edition of the code had been published (publisher’s edition: current through Ordinance 2026-515, and legislation passed through May 26, 2026).
Full Breakdown
020 expressly excludes the Residential Resource (RR) zone. A, the density within all zones may exceed the maximum density set in Title 18A PCC for the entire site, including the portion not devoted to low-income housing. 0 bonus unit for every low-income owner-occupied unit, entire project area, capped by the density limitation table at 133% of maximum density in single-family residential zones and 120% of maximum density in multi-family or mixed-use zones that allow multi-family development. Accessory dwelling units are barred from developments that use this density bonus.
B) identifying every incentive claimed, the minimum number of affordable units required, and breach-of-contract terms; a breach lets the County place a lien against the project's properties. 540), secured by a recorded covenant and lien binding all successors. b requires paying the County 20 percent of net sale proceeds. The Pierce County Human Services Department monitors continued affordability of both rental and owner-occupied units, and Planning and Public Works reports annually to the County Council on units built under the chapter.
Violations & Fines
A project that builds under the density bonus but fails to deliver the promised affordable units breaches its recorded Affordable Housing Incentives Program Agreement under PCC 18A.65.030.B.6, exposing the developer to a breach-of-contract action and a County lien against all associated properties. Converting an affordable unit to market-rate use before the 50-year affordability period ends triggers repayment of current impact fees under PCC 18A.65.030.A, plus a 20 percent net-proceeds payment to the County under PCC 18A.65.030.G.1.b where only regulatory incentives were granted.
Frequently Asked Questions
How much extra density can a Pierce County project get for building affordable units?
Does every zone in unincorporated Pierce County qualify for the density bonus?
What happens if a developer takes the density bonus but does not build the affordable units?
How long must the affordable units created by the density bonus stay affordable?
Sources & Official References
Other rules in Pierce County
Compare Pierce County to another location·View the Washington zoning overlays & bonuses overview
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