Marion County, OR Accessory Structures: Garage Conversions (2026)
Garage conversion rules in Marion County, OR, sometimes called garage-to-ADU or accessory living unit conversions, govern permits, ceiling height, egress, and parking replacement.
Key Facts
- Code section
- MCC 17.117.070
- Attached garage
- Treated as part of dwelling
- 'Attached' means
- Within 5 feet of home
- Separate unit
- Regulated as an ADU
- Permit needed
- Yes, building permit
Summary
In Marion County, an attached garage converted to living space is treated as part of the dwelling and must meet the same zoning and building-code standards. A detached garage turned into a living unit is regulated as an ADU or separate dwelling.
Covered or enclosed accessory buildings which are attached to the dwelling shall be considered as a portion of the dwelling and shall observe the same requirements as the dwelling. Accessory structures shall be considered as being attached to the dwelling when any portion of the accessory structure is located within five feet of the dwelling.
Full Breakdown
Under Marion County Rural Zoning Code 17.117.070, covered or enclosed accessory buildings attached to the dwelling are considered part of the dwelling and must observe the same yard and code requirements; a structure within five feet of the home counts as attached. Converting that garage into habitable rooms therefore requires a building permit and compliance with Oregon's one- and two-family dwelling code for ceiling height, egress, light, ventilation, and smoke and carbon-monoxide alarms. If the conversion creates a separate living unit, it is an accessory dwelling unit under ORS 197.312 and follows ADU zoning. Oregon law (ORS 455.610) also provides an alternate approval path for converting older single-family homes into up to four units.
Violations & Fines
An unpermitted garage conversion is a building- and land-use-code violation enforced by the county or city. Remedies include stop-work orders, a retroactive permit, fines, or an order to restore the garage or vacate the space.
Frequently Asked Questions
Can I convert my garage to a bedroom in Marion County?
Does a converted garage need to meet building code?
Sources & Official References
Other rules in Marion County
Compare Marion County to another location·View the Oregon accessory structures overview
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