Hillsboro, OR Building Setbacks & Zoning: Structure Height Limits (2026)

Table 12.21.450-1, referenced in Section 12.21.450, sets the base development standards for Hillsboro's R-6 residential zone, including minimum lot sizes of 6,000 square feet for a single detached dwelling, duplex or triplex and 7,000 square feet for a quadplex or cottage cluster, reflecting the middle-housing types Oregon's HB 2001 requires the city to allow. Within that table, the row for 'Maximum Building Height' reads '2½ stories or 35 feet, whichever is less,' with a note directing readers to 'see measurement and illustration in Section 12.50.140' and to the half-story definition in Section 12.01.500.

There is no minimum building height in the R-6 zone. Section 12.50.140(B) supplies the measurement rule the table incorporates: except as otherwise provided, 'building height is measured from finished grade at the center of the front building plane,' and Figure 12.50.140-A illustrates separate measurement methods for flat roofs, mansard roofs, and pitched or hip roofs, since a peaked roof's highest point is not simply averaged the same way as a flat parapet. The height standard applies to structures built after September 4, 2014, the effective date named in Subsection B.1, and can only be exceeded through a Variance or Adjustment approved by the Review Authority under Section 12.80.150.

Cottage clusters get a separate, more permissive height allowance under Subsection 15.50.715.E.4 rather than the 35-foot cap. The R-6 table pairs the height limit with a maximum lot coverage of 55% on interior lots and 60% on corner lots, and setbacks such as a 20-foot front yard to the dwelling or garage door and a 5-foot side yard, all illustrated together in Figure 12.21.450-A so that height, coverage and setback interact as a single development envelope rather than isolated numbers.