Utah's HB 82 made internal ADUs a permitted use in every Davis County residential zone. But the local details — parking, owner-occupancy, short-term rental, detached unit rules — vary city by city. This is the quick reference we use ourselves when we're scoping a project. Updated October 2025.
For the deeper background on what HB 82 actually says, see our plain-English HB 82 guide.
Syracuse
- Internal ADUs: Permitted use in residential zones (HB 82)
- Detached ADUs: Subject to local zoning — confirm with planning
- Parking: One additional off-street space
- Minimum size: Syracuse has a minimum total floor area requirement for ADUs that surprises some homeowners
- Permit: Required for any structural work over 200 sq ft
- Building department: Syracuse City Building Inspection
Layton
- Internal ADUs: Permitted in all SFR zones
- Detached ADUs: Allowed with additional setback rules; subject to lot size
- Owner-occupancy: Required
- Short-term rental: Prohibited — important if you were thinking Airbnb
- Building department: Layton City Building Division
Clearfield
- Internal ADUs: Permitted use per HB 82
- Detached ADUs: Subject to lot size and setback requirements
- Older housing stock means more existing-condition evaluation work for any ADU project
- Building department: Clearfield City Building Department
Kaysville
- Internal ADUs: Permitted
- Detached ADUs: Allowed with stricter setback and lot-coverage rules; lot size matters
- Design standards: Some neighborhoods have additional architectural review
- Building department: Kaysville City Building Department
Farmington
- Internal ADUs: Permitted use per HB 82
- Detached ADUs: Allowed with setback rules; check planning before design
- Bench lots may have additional geo-hazard or hillside review
- Building department: Farmington City Building
West Point
- Internal ADUs: Permitted use per HB 82
- Detached ADUs: Local ordinance — confirm with city
- Many lots are agricultural-residential with specific use rules
Clinton
- Internal ADUs: Permitted use per HB 82
- Newer housing stock means most ADU conversions are basement or above-garage
Bountiful, Centerville, Fruit Heights
These southern Davis County cities also follow HB 82 for internal ADUs. Detached unit rules vary; older Bountiful neighborhoods sometimes have historic-overlay considerations for any external structural work. Confirm with the relevant city building department before designing.
The universal rules across all Davis County cities
- You always need a building permit
- You always need stamped structural plans for new framing, openings, or any meaningful work
- You always need to meet the IRC and local snow/seismic loads
- Egress windows are required in any sleeping room — basement ADUs almost always need an engineered cut and header
- Fire separation between units is required (typically 1-hour rated assembly)
What we'd do next
Send us your address and a description of what you're hoping to build (internal, garage conversion, detached, etc.). We'll come back with a fixed fee for the engineering scope, an honest read on what your specific city is going to require, and a timeline. See our ADU services page for more.