Hillsboro, OR Accessory Structures: Shed & Carport Rules (2026)

104 defines accessory structures as buildings 'used by the residents, customers, or employees of the primary structure(s) on the site,' expressly naming 'playhouses, storage sheds, detached garages or workshops, and greenhouses' as residential examples, plus accessory equipment such as HVAC units and satellite dishes. 1, an accessory structure must meet the applicable zone or plan district's setback standard unless that zone has its own placement rules, which then override this section. 2 offers a reduced-setback path: side and rear yard setbacks shrink to 3 feet for a residential accessory structure if it satisfies all five listed specifications together: a footprint of 450 square feet or less measured at the outside of the foundation; no more than one story, capped at 10 feet measured from the roof's mid-point between peak and eave; eaves at least 2 feet from the side and rear property lines; placement behind the dwelling's front building plane (and, on corner, through, or multiple-frontage lots, behind the front building plane on every street); and at least 6 feet of separation from any other structure on the site.

3 caps total lot coverage: the combined footprint of the primary structure and every accessory structure cannot exceed the applicable zone's maximum lot coverage standard, though middle housing developments may exceed that cap by up to 10%. 4 requires accessory equipment, whether ground-mounted or wall-mounted, to stay clear of any required emergency access route or clearance around the building.