Tigard, OR Building Setbacks & Zoning: Lot Coverage Limits (2026)

Table 18.290.1 in Tigard Municipal Code § 18.290.040 sets Maximum Lot Coverage for small form residential development at 80% in the RES-A, RES-B, RES-C, and RES-D and RES-E columns and 90% in the MUC-1 column. The same table prints minimum setbacks, maximum height, and a minimum landscape area of 20% in the RES columns and 10% in MUC-1, planted to the L-1 standard. A table note limits the RES-E column to lots with existing nonconforming development, because new small form construction is not allowed there except as provided in Chapter 18.50.

What counts toward the cap is defined in § 18.30.020: lot coverage is the percentage of lot area covered by the horizontal projection of all structures, buildings, and other impervious surfaces. Paving and structures both use the allowance.

Accessory structures sit inside the same limit. Section 18.290.050 allows them on small form lots, but they cannot cause the lot to exceed the maximum lot coverage allowed in the base zone. They are capped at 528 square feet on lots less than 2.5 acres and 1,000 square feet on lots 2.5 acres or larger, with a maximum height of 15 feet. Detached accessory dwelling units must meet the lot coverage standards for small form residential development in the applicable base zone under § 18.220.040.E.

Other development types in the City of Tigard carry their own numbers. Table 18.320.1 prints Maximum Lot Coverage of 100% for nonresidential development in the COM, MUC, MUE, and MUR zones, with a 0% minimum landscape area. Table 18.330.1 prints 85% for the IND zone with a 15% minimum landscape area. Section 18.350.040.C sets the maximum lot coverage at 85% for nonresidential development in residential zones, with at least 15% of the site landscaped. Apartments, rowhouses, quads, cottage clusters and courtyard units each have separate chapters in Part 18.200, and plan districts add standards of their own.