ADU rules in Hillsboro, OR — also called accessory dwelling unit regulations or granny flat ordinances — cover setbacks, owner-occupancy, parking, and permit requirements.
Hillsboro allows ADUs on all single-family lots per Oregon HB 2001. ADUs are capped at 800 square feet. Both attached and detached types are permitted.
Hillsboro permits accessory dwelling units on all single-family lots per Oregon House Bill 2001. As a city over 25,000, Hillsboro must also allow middle housing. ADUs are capped at 800 square feet. Both attached and detached ADUs are allowed. Building permits are required. Owner occupancy requirements have been relaxed under state law. ADUs are approved ministerially without discretionary review.
Unpermitted ADUs face enforcement. Non-compliant structures must meet code.
Hillsboro, OR
Hillsboro Municipal Code Subchapter 6.24 prohibits unauthorized, disturbing, or unnecessary noise. Noise levels are especially enforced between 9 PM and 6 AM...
Hillsboro, OR
Hillsboro addresses barking dogs through its noise ordinance and animal control. Persistent barking is a nuisance violation. Washington County Animal Service...
Hillsboro, OR
Hillsboro permits construction, industrial, and agricultural noise between 6 AM and 9 PM per Subchapter 6.24. Construction outside these hours is prohibited ...
Hillsboro, OR
Vehicles in Hillsboro driveways must not block sidewalks. Driveway modifications require permits from the city's permitting center.
Hillsboro, OR
Hillsboro restricts RV and boat parking on streets and in residential front yards. RVs may not be used as dwellings on residential property.
Hillsboro, OR
Hillsboro regulates on-street parking. Vehicles must be registered and operable. Vehicles may not remain in the same location for more than 72 hours without ...
Side-by-side rule comparisons with other cities in Washington County.
See how other cities in Washington County handle adu rules.
See how Hillsboro's adu rules rules stack up against other locations.
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