Cowlitz County, WA Building Setbacks & Zoning: Lot Coverage Limits (2026)
Key Facts
- RR-1 max coverage
- 50%
- RR-5 max coverage
- 15% (largest-lot rural district)
- SR/UR max coverage
- 65% each
- MF max coverage
- 90%
- Table location
- Table 18.10.501, CCC § 18.10.501
Summary
Cowlitz County's Table 18.10.501 caps maximum lot coverage by zoning district for unincorporated land: 50% in the RR-1 district, 30% in RR-2, 15% in the large-lot RR-5 district, 65% in both the SR and UR districts, and 90% in the Multiple-Family (MF) district, under Cowlitz County Code § 18.10.501.
Table 18.10.501 Minimum Zone District Development Standards Land Use Zone District Lot Area (acres or sq. ft.) Lot Width at Building Line (feet) Rear Yard Setback (feet) Side Yard Setback (feet) Building Height (feet) Maximum Lot Coverage (percentage) Minimum District Size (acres) RR-1 1 acre 120 15 5 (CCC § 18.10.535) 50 — RR-2 2 acres 180 15 10 (CCC § 18.10.535) 30 — RR-5 5 acres 300 15 10 (CCC § 18.10.535) 15 — SR 15,000 sq. ft. 60 15 5 (CCC § 18.10.535) 65 — UR 6,000 sq. ft. 60 15 5 (CCC § 18.10.535) 65 — MF Table 18.10.541 — 15 5 (CCC § 18.10.535) 90 —
Full Breakdown
501, and that the table sets only minimum standards, so stricter limits imposed by building codes, fire codes, stormwater rules or sewage disposal regulations control where they conflict. 541. Between those, RR-1 allows 50% coverage, RR-2 allows 30%, and both SR and UR allow 65%. 502. A property owner calculates the allowed building footprint by applying the applicable district's percentage to the lot's total area, and must still meet the district's lot width, setback and building height standards from the same table.
Violations & Fines
Building or paving beyond the maximum lot coverage percentage set in Table 18.10.501 for the applicable zoning district is a Land Use Ordinance violation under Chapter 18.10 CCC. CCC § 2.06.040 makes exceeding the standard a civil infraction, and § 2.06.080 sets the penalty at $1,000 per violation, doubling to $2,000 for a second violation of the same ordinance within three years and tripling for a third.
Frequently Asked Questions
What percentage of my lot can I build on in Cowlitz County's RR-1 zone?
Is lot coverage lower on larger rural lots?
Does Cowlitz County cap lot coverage in commercial and agricultural zones?
Sources & Official References
Other rules in Cowlitz County
Compare Cowlitz County to another location·View the Washington building setbacks & zoning overview
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