Pierce County, WA Building Setbacks & Zoning: Lot Coverage Limits (2026)
Key Facts
- No-principal-use structure cap
- 576 sq ft combined (18A.37.020.B)
- Lots under 1 acre, principal use present
- 2,000 sq ft detached structure cap (18A.37.020.C)
- Shared garage/carport exemption
- Exempt per PCC 18J.17.020.E
- ADU treatment
- Governed separately, PCC 18A.37.120
- Code enforcement appeal fee
- $250 (2026-2027 schedule)
- Appeal forum
- Hearing Examiner, Chapter 1.22 PCC
Summary
In unincorporated Pierce County, detached accessory structures on residential lots under 1 acre cap out at 2,000 total square feet under PCC 18A.37.020.C. Structures built with no principal use on site are capped even lower, at 576 square feet combined, under PCC 18A.37.020.B.
B. Structures typically accessory to a residence, such as garages or carports, greenhouses and storage buildings, may be permitted without a principal use up to a maximum of 576 total square feet. Such structures shall not be used as living accommodations. Fences and retaining walls shall not be considered a principal use and shall not be limited to the 576 square feet maximum when no principal use is located on site. C. In residential zones, on lots of less than 1 acre in size, detached unoccupied accessory structures shall not exceed 2,000 total square feet. Shared garages or carports allowed in PCC 18J.17.020.E are exempt from the 2,000-square-foot size limit. See PCC 18A.37.120 for regulations pertaining to Accessory Dwelling Units.
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 governs how much of a residential lot accessory buildings can occupy. Subsection B lets garages, carports, greenhouses and storage buildings go up without a principal residence on the parcel, but caps them at 576 total square feet combined, and bars using them as living space; fences and retaining walls are excluded from that 576-square-foot cap when no principal use exists on the lot. Subsection C then sets the residential-zone ceiling once a principal use is present: on lots smaller than 1 acre, detached unoccupied accessory structures cannot exceed 2,000 total square feet.
120 rather than counted against this cap. E. Subsection D requires every accessory use to remain customarily incidental and subordinate to the principal building, and Subsection E forces removal or discontinuance of accessory uses once the principal use they serve is discontinued. Where it is unclear whether a structure counts as an accessory use in a given zone, Subsection F gives the Planning and Public Works Director final authority to decide, weighing the structure's size and placement against the predominant surrounding land-use pattern and the zone's permitted principal uses.
The section was last amended by Ordinance 2025-516s Section 4 in 2025, building on Ordinance 2021-31s Section 7 (2021) and the original 2016 codification (Ordinances 2016-33 and 2016-14s).
Violations & Fines
Pierce County Planning and Public Works enforces the 576- and 2,000-square-foot caps through code enforcement complaints and site inspections; an oversized detached structure is a zoning violation subject to a correction order. A property owner who disputes a Code Enforcement Administrative Decision can appeal it for a $250 fee (2026-2027 fee schedule), with appeals proceeding under the Pierce County Hearing Examiner Code, Chapter 1.22 PCC. Structures exceeding the caps without qualifying for the shared-garage or ADU exemptions must be reduced in size or removed, or the owner must pursue a Conditional Use Permit review if the underlying use itself is in question.
Frequently Asked Questions
How big can a detached garage or shop be on my Pierce County lot?
Do fences count against my accessory structure square footage?
Does a shared garage push me over the 2,000-square-foot limit?
What happens if my accessory structure is bigger than the code allows?
Sources & Official References
Other rules in Pierce County
Compare Pierce County to another location·View the Washington building setbacks & zoning overview
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