Salt Lake County · 204,657 residents
Salt Lake City ADU rules
Salt Lake City: internal ADUs allowed; detached ADUs allowed. Owner occupancy applies.
Internal ADU (inside the home)
Detached ADU (backyard building)
Not yet fully verified · last reviewed September 7, 2026 See sources
Salt Lake City ADU rules at a glance
| Rule | Internal ADU (basement, attic, inside the home) | Detached ADU (backyard building) |
|---|---|---|
| Allowed? | Allowed | Allowed |
| Minimum lot | No ADU-specific lot-size minimum in the city ADU handbook; statewide internal-ADU rules also limit local lot-size floors for one qualifying internal unit. | No citywide detached lot-size floor in the ADU handbook. S.B. 284’s ≥11,000 sq ft statewide floor mainly reinforces practice SLC already exceeds. |
| Owner occupancy | Required on single-family lots: owner (or qualifying family / family-trust trustor) must live in the main dwelling or the ADU. Duplex/multi-family/non-residential principal uses and temporary-absence exceptions differ—confirm before design. | Same as internal on single-family lots: owner/family must occupy either the main dwelling or the ADU (with the same exceptions). |
| Parking | +1 off-street stall for the ADU (may be in driveway), with waivers if the zone has no parking minimum, the lot already has an extra accessible stall, within ¼ mile of transit, or within ½ mile of a city-designated bike lane/path. | Same as internal: +1 stall with transit/bike and related waivers available. |
| Size limits | No maximum floor-area cap for internal/attached ADUs in the city handbook; additions still meet principal-building bulk/coverage of the zone. | Cannot exceed the existing main building and cannot exceed 1,000 sq ft (whichever is less). Covered patio roof ≤120 sq ft does not count toward ADU area but counts toward lot coverage. |
| Height | Attached additions follow the underlying zoning district height limit. | Base max 17 ft; up to 24 ft (pitched) or 20 ft (flat) if setbacks increase as required. |
| Setbacks | Internal conversions follow principal-building rules; attached additions use the underlying district’s front/side/rear setbacks. | Side/rear minimum 3 ft; corner side minimum 10 ft or 20% of lot width (lesser). Height over 17 ft increases required setbacks 1:1. Accessory buildings together cannot cover more than 50% of the rear yard in residential districts. |
| Zones | Allowed where residential uses are permitted—verify the parcel. | Same eligibility as internal—districts where residential uses are permitted. |
| Permit process | Administrative building-permit path (no Planning Commission hearing for a standard ADU). If renting: business license, Good Landlord Program, owner-occupancy proof, and recorded deed restriction. Historic Landmark COA if in a historic district. | Same administrative building-permit path as internal ADUs (permitted use since 2023 streamlining). Site review still required; solid perimeter foundations required. |
What the Salt Lake City council decided
Recorded votes and actions on ADU rules, linked to the public meeting record on OpenUtah.
· Community Reinvestment Agency (CRA) Meeting · Approved (7-0)
CRA Board adopted Resolution 1 of 2026 amending and restating the terms of its Accessory Dwelling Unit Financing Program.
Read the meeting record· Community Reinvestment Agency (CRA) Meeting · Approved (7-0)
CRA Board adopted Resolution 01 of 2025 approving the ADU financing program allocation for fiscal year 2024-25.
Read the meeting record
State law: detached ADUs from October 1, 2026
Salt Lake City is a “specified municipality” under Utah S.B. 284. Beginning October 1, 2026, it must permit one detached ADU as a permitted use on a lot of 11,000 sq ft or more that has a detached single-family home. The city can still apply setbacks, height, design, owner-occupancy and limited parking rules, and it may allow detached ADUs on smaller lots. How the state ADU laws work.
How our property map screens Salt Lake City lots
The map colors parcels using the rules on this page and the recorded lot size. A color is a planning screen, not a permit; Salt Lake City makes the decision.
- No numeric external minimum is recorded for Salt Lake City. The map keeps the statewide 11,000 sq ft external screen and shows the researched status (generally allowed) on the property report.
- "Likely" above 15,000 sq ft is this site's planning band for a large recorded lot. It is not a sentence in the Salt Lake City code. Owner occupancy, parking, setbacks, zones, and HOA rules below still have to be checked.
Planned communities, PRDs and PUDs
Reviewed on September 22, 2026 against this city's research file, its published ADU page where one was found, and Utah meeting packets. No adopted sentence was confirmed that allows or bans an ADU in every PUD, PRD, PRUD, or planned community. If the assessor class or subdivision name says PUD, PRD, PRUD, planned unit development, planned residential development, planned community, resort community, or master planned community, the map keeps that lot highly unlikely regardless of size. A plat, CC&Rs, or development agreement can still prohibit an ADU where the zone allows one.
Planning notes for Salt Lake City
Salt Lake City offers pre-approved standard ADU plans, including several detached and garage-conversion concepts. Pre-approval of a plan does not approve your property: a site review is still required. We can help compare a standard-plan route with a custom design and identify zoning, site and rental-operation questions early.
Bring these to your review
- Lot dimensions and proposed building placement
- Preferred standard-plan or custom layout
- Existing permits and intended occupancy
The question to resolve first
Would a standard plan suit your site, or would a custom layout better address the property’s constraints?
Sources
We link only to government sources and public meeting records. Codes change; confirm the current version with Salt Lake City before you apply.
- Salt Lake City ADU standard plans
Published city program; a site review is still required
- Utah S.B. 284 (2026), enrolled bill
Statewide detached-ADU requirements for specified municipalities, operative October 1, 2026.
- Official Salt Lake City website
Common Salt Lake City ADU questions
Can you build an ADU in Salt Lake City?
Salt Lake City: internal ADUs allowed; detached ADUs allowed. Owner occupancy applies. This is planning guidance, not a permit. Confirm the zone on your parcel with Salt Lake City.
What lot size does Salt Lake City require for an ADU?
Internal ADU: No ADU-specific lot-size minimum in the city ADU handbook; statewide internal-ADU rules also limit local lot-size floors for one qualifying internal unit. Detached ADU: No citywide detached lot-size floor in the ADU handbook. S.B. 284’s ≥11,000 sq ft statewide floor mainly reinforces practice SLC already exceeds.
Does Salt Lake City require the owner to live on the property?
Internal ADU: Required on single-family lots: owner (or qualifying family / family-trust trustor) must live in the main dwelling or the ADU. Duplex/multi-family/non-residential principal uses and temporary-absence exceptions differ—confirm before design. Detached ADU: Same as internal on single-family lots: owner/family must occupy either the main dwelling or the ADU (with the same exceptions).
How much parking does a Salt Lake City ADU need?
Internal ADU: +1 off-street stall for the ADU (may be in driveway), with waivers if the zone has no parking minimum, the lot already has an extra accessible stall, within ¼ mile of transit, or within ½ mile of a city-designated bike lane/path. Detached ADU: Same as internal: +1 stall with transit/bike and related waivers available.
What does it cost to build an ADU in Salt Lake City?
Wasatch Front planning bands are often about $55,000–$145,000 for an internal suite, $70,000–$175,000 for a garage conversion, and $95,000–$250,000 or more for a new detached unit, before unusual site work. These are planning ranges, not bids.
Can an HOA block an ADU in Salt Lake City?
City approval does not override CC&Rs or plat notes. Read the HOA documents and your subdivision plat before you design. A private restriction can stop a unit the city would otherwise allow.
Before you design: general checks for any Utah ADU
General planning advice, not Salt Lake City code.
- Confirm the zoning district on the city zoning map. The county assessor’s “residential” class is not zoning.
- Read your HOA CC&Rs and subdivision plat notes; private restrictions can block a unit the city allows.
- Sketch existing and proposed parking. Driveway geometry and access often decide what fits.
- Ask early about sewer, water and electrical capacity; utilities can force a redesign.
- Expanding a building’s footprint usually triggers full setback and height rules.
Nearby city ADU rules
Want to know what fits on your Salt Lake City lot?
Free, no obligation. We review your parcel against these rules and, if you want, introduce independent design and construction partners. Partners may pay us for referrals.
Utah ADU Builder provides educational planning guidance. This page is not legal advice and not a permit. Population: UGRC POPLASTESTIMATE / Census-derived municipal estimates (manual fill where UGRC blank). Editorial standards.