Portland, OR Building Setbacks & Zoning: Lot Coverage Limits (2026)
Key Facts
- Zones covered
- RF through R2.5
- Small-lot max
- 50% of lot area
- Large-lot max
- 7.5% over 20,000 sq ft
- Governing standard
- Table 110-5
Summary
Portland caps building footprint by lot size in single-dwelling zones, from 50% on small lots down to a sliding percentage on larger ones.
B. Building coverage standards. The maximum combined building coverage allowed on a site for all covered structures is stated in Table 110-5. ... Less than 3,000 sq. ft.: 50% of lot area. 3,000 to 5,000 sq. ft.: 1,500 sq. ft. + 37.5% of lot area over 3,000 sq. ft. 5,000 to 20,000 sq. ft.: 2,250 sq. ft + 15% of lot area over 5,000 sq. ft. 20,000 sq. ft. or more: 4,500 sq. ft. + 7.5% of lot area over 20,000 sq. ft.
Full Breakdown
In the RF through R2.5 single-dwelling zones, Portland City Code § 33.110.225 sets the maximum combined building coverage for all covered structures on a site by a formula tied to lot size: lots under 3,000 sq ft can cover 50% of the lot; larger lots get a base square footage plus a shrinking percentage of the area above each threshold, down to 7.5% on lots over 20,000 sq ft. Coverage works alongside height, setback, and floor-area-ratio standards to limit building bulk.
Violations & Fines
Building Permits requires plans showing compliance with the coverage table before issuing a permit; exceeding the standard triggers Bureau of Development Services plan review rejection or a code compliance case if built without approval.
Frequently Asked Questions
What is Portland's maximum lot coverage for a house?
Does this cap include garages and accessory buildings?
Sources & Official References
Other rules in Portland
Compare Portland to another location·View the Oregon building setbacks & zoning overview
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Lot Coverage Limits in Nearby Cities
How other cities in Multnomah County handle lot coverage limits.