Salt Lake County, UT Accessory Structures: ADU Rules (2026)
ADU rules in Salt Lake County, UT, also called accessory dwelling unit regulations or granny flat ordinances, cover setbacks, owner-occupancy, parking, and permit requirements.
Key Facts
- Building permit
- Required before construction
- Affidavit
- Recorded against title
- License
- Business license before renting
- On resale
- New affidavit + reauthorization required
Summary
An ADU in unincorporated Salt Lake County needs a building permit before construction, an owner-occupancy affidavit recorded against the property, and a business license before it can be rented.
A. An approved building permit is required for all ADUs before an ADU is constructed, and all other applicable provisions of this chapter and the Salt Lake County Code must be met before an ADU can be rented. ... B. A building permit may not be issued for an ADU until the applicant has provided written confirmation from the applicable water supplier that the ADU complies with all applicable water service requirements.
Official source re-checked September 7, 2026: no newer edition of the code had been published (publisher’s edition: Code of Ordinances: Supplement 49).
Full Breakdown
The county requires an approved building permit before any ADU is built, and it can't be rented until every other chapter requirement is met. Applicants must also file a recorded affidavit stating the owner will live in either the primary home or the ADU, and after the building official approves the unit and a business license issues, a notice of accessory dwelling unit is recorded against the property so future buyers see the owner-occupancy condition. Selling the property triggers a new affidavit and reauthorization by both the building and business license officials. Applies only to unincorporated county ADUs.
Violations & Fines
Renting an ADU without the required building permit, recorded affidavit, and business license is a code violation; a new owner who doesn't re-file and re-authorize also violates the ordinance.
Frequently Asked Questions
Do I need a permit before building an ADU in Salt Lake County?
What happens to the ADU authorization when I sell my house?
Sources & Official References
Other rules in Salt Lake County
How Salt Lake County compares: Easiest Cities to Build an ADU·Compare Salt Lake County to another location·View the Utah accessory structures overview
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