Side by side · Utah
Compare ADU rules across Utah
Flexible on where you build? The same backyard cottage can be routine in one city and impossible next door. This table puts 27 Utah cities side by side so you can shortlist the friendly ones before reading a single ordinance, or narrow it to just the cities you are deciding between. Every value is summarized from the city's own code; open a city's page for the full notes, citations, and fine print.
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| City | Detached ADU | Attached / internal | Max size | Owner occupancy | Extra parking | Approval |
|---|---|---|---|---|---|---|
| Alpine | Not allowed | Allowed | no explicit size cap in the ADU section | Required | 4 off-street spaces total for the lot; at least 1 designated for the ADU | In the TR-10,000, CR-20,000, CR-40,000, and CE-5 zones ADUs are a permitted use requiring an ADU permit from the Building Department (in addition to any building permits). In the CE-50 zone ADUs are listed as a conditional use requiring approval by the designated review agency. Ordinance read July 2026 |
| American Fork | Not allowed | Allowed | no explicit size cap in the ADU section | Required | 2 off-street spaces, in addition to the 2 required for the single-family home | Permitted use |
| Bluffdale | Allowed | Allowed | 50% of primary dwelling floor area | Required | 1 space (internal ADU), 2 spaces (detached ADU) | Permitted use |
| Bountiful | A detached ADU is a conditional use reviewed and approved by the Bountiful City Administrative Committee, and only within the Single-Family Residential zone, Residential Multiple (RM) Family Zone, and Downtown (DN) Mixed Use Zone; not permitted in any other zone. The property must be owner occupied and contain a habitable single-family dwelling (ADUs are unlawful on duplex or multi-family properties). Ordinance read July 2026 | Allowed | 1,250 sq ft, 350 sq ft minimum (detached); no explicit size cap (internal) | Required | 1 off-street space for the ADU, in addition to the principal unit's parking | Internal ADUs are a permitted use reviewed and approved by City Staff (permit fee $125). Detached ADUs are a conditional use requiring approval by the Bountiful City Administrative Committee, and residing in one without a conditional use permit is unlawful. Ordinance read July 2026 |
| Cedar Hills | ADUs are permitted in all residential zones as a conditional use, and the parking rules expressly contemplate accessory dwellings not internal to the single-family dwelling (two spaces required). But nearly every other condition is written for accessory apartments inside a single-family home, and the appearance clause requires the home to keep its single-family look, so confirm detached feasibility with the city before designing one. Ordinance read July 2026 | Allowed | no explicit size cap in the ADU section | Required | 1 space (internal ADU), 2 spaces (non-internal ADU) | Conditional use permit approved administratively by the Zoning Administrator and building official (the section names no planning-commission hearing), plus a one-time registration fee and ADU registration with a site plan. The permit is valid for the year issued and auto-renews on evidence of owner occupancy and continued compliance; unregistered units are not legal. Ordinance read July 2026 |
| Coalville | Allowed | Allowed | 1,000 sq ft or 2/3 of the primary dwelling, whichever is less (detached); no size cap stated in the IADU standards | Owner occupancy is tied to rental, not creation: renting an IADU or a DADU is not allowed unless the primary dwelling is occupied as the owner's primary residence (§03-230.C.8 and §03-230.D.9). No owner-occupancy requirement is stated for an ADU housing the owner's relatives, domestic help, or house guests. Ordinance read July 2026 | 1 on-site space in addition to the primary dwelling's parking requirement (both IADU and DADU) | Permitted use |
| Cottonwood Heights | Detached ADUs may be allowed as conditional uses in the R-1 (single-family), RR-1 (rural residential), and F-1 (foothill residential) zones; requires planning commission approval following a public hearing. Must be a permanent structure in the rear yard, set back at least 6 feet from the primary structure, and meet accessory building standards for the zone. Ordinance read July 2026 | Allowed | No explicit square-footage cap in the ADU chapter | Required | Internal ADU: 1 additional off-street space (minimum 3 total on the property); Detached ADU: 2 additional off-street spaces | Internal ADUs are permitted uses (by right, but still require an ADU application, inspection, affidavit, and annual permit renewal). Detached ADUs are conditional uses requiring planning commission approval after a public hearing, also with annual renewal. Ordinance read July 2026 |
| Draper | Allowed | Allowed | D-ADU: 50% of the single-family dwelling's total square footage (excluding garage) | Required | 1 additional off-street space | Permitted use |
| Elk Ridge | Accessory apartments may be located in a permanent accessory building associated with an owner-occupied single-family dwelling (§10-12-29(A)(2), (B)(1)); §10-12-6 permits living quarters in an accessory building only as an accessory apartment under that chapter. They are listed only as conditional uses in the residential zones (R-1-15,000, R-1-20,000, R-1-12,000, RR-1, R&L-1-20,000, HR-1, CE-2, CE-3) and are expressly not permitted in the Senior Housing Overlay Zone. §10-12-29(A)-(C); §10-12-6; §10-7A-3 and parallel zone conditional-use sectionsFull rules for Elk Ridge Ordinance read July 2026 | An accessory apartment within a single-family dwelling (a portion of the dwelling with separate cooking, sleeping and sanitary facilities per the §10-2-2 definition) may be approved subject to the §10-12-29 standards; every residential zone lists accessory apartments as a conditional use, not a permitted use (e.g. §10-7A-3), so approval is case by case. Ordinance read July 2026 | no maximum stated; 300 sq ft minimum | Required | 2 off-street spaces in addition to the primary dwelling's required spaces | Every residential zone lists accessory apartments as a conditional use (e.g. §10-7A-3), and §10-12-33 makes the CUP discretionary (approve, deny or conditionally approve against 12 factors) with mailed notice to property owners within 300 feet before the review meeting (§10-12-37). §10-12-29(B)(1) states accessory apartments may be approved by city administration upon findings of conformance, so review can be administrative rather than a planning commission hearing in most zones; in CE-3 the zone article requires Planning Commission and City Council approval (§10-9C-6-2). An accessory apartment permit plus annual renewal is also required. Ordinance read July 2026 |
| Lindon | Detached accessory apartments are allowed, but only in conjunction with an owner-occupied single-family dwelling that was not approved as part of an R2 overlay project; they are prohibited on lots of 6,000 sq ft or less and in the areas shown on the Lindon City Accessory Apartment Map. Detached units carry extra height, setback, size, design, and utility requirements. Ordinance read July 2026 | Internal accessory apartments and apartments in garages or accessory buildings substantially attached to the main dwelling (by covered walkway, breezeway, or porch, within 18 feet) are allowed under the same conditions: owner-occupied single-family dwelling, lot larger than 6,000 sq ft, not in a map-prohibited area, and not part of an R2 overlay project. One accessory apartment maximum per dwelling. Ordinance read July 2026 | Detached: 1,500 sq ft or 40% of the primary dwelling, whichever is less; substantially attached (garage/accessory building): 60% of the primary dwelling footprint, max 1,200 sq ft; internal: no size restriction | Required | 1 off-street stall for an internal ADU; 2 off-street stalls for a detached or substantially attached ADU (in addition to 2 stalls for the primary dwelling) | Permitted use |
| Mapleton | An accessory apartment may be permitted in a detached building only on lots of at least 21,780 sq ft (half acre); the detached structure's front wall must be at least 10 ft behind the front wall of the primary dwelling. Unlike the internal-unit subsection, the detached subsection does not list eligible zones. Ordinance read July 2026 | Allowed | Detached: lesser of 40% of the primary dwelling or 1,000 to 1,400 sq ft by lot size; no explicit cap for internal units | Required | 1 designated off-street stall in addition to the primary dwelling's required parking | Permitted use |
| Midvale | Allowed | Allowed | Larger of 900 sq ft or 13% of lot area (EADU, cumulative with all unoccupied accessory structures) | Required | 1 space per ADU | Permitted use |
| Millcreek | Allowed | Allowed | 1,000 sq ft (detached) | Required | 1 space | Permitted use |
| Murray | Allowed | Allowed | 1,000 sq ft (detached) | Required | 1 additional space (3 total off-street) | Permitted use |
| North Salt Lake | Allowed | Allowed | 1,200 sq ft and 2 bedrooms (detached; 300 sq ft minimum); basement units may occupy the entire basement | Required | 1 additional off-street space; 1 more for ADUs with 2+ bedrooms; no tandem parking | Permitted use |
| Ogden | Allowed | Allowed | 800 sq ft (detached; 300 sq ft minimum); no explicit cap for attached or internal units | Required | No additional spaces for the ADU; the dwelling's required 2 off-street spaces must already exist | Permitted use |
| Orem | Not allowed | Accessory apartments (defined in §22-2 as a subordinate dwelling with its own eating, sleeping, and sanitation facilities within a single-family dwelling) are allowed only in owner-occupied detached single-family dwellings, and are prohibited in any R5 zone or PRD zone. Maximum one accessory apartment per dwelling (§22-6-9(I)(2)). Ordinance read July 2026 | no explicit size cap in the accessory apartment section | Required | 1 additional on-site stall (8 ft by 16 ft) for the apartment | Permitted use |
| Park City | Detached Accessory Apartments are allowed, but only on lots of 3,750 sq ft or greater; they must meet the zoning district setbacks for single-family dwellings, stay within recorded plat disturbance limits, and may not exceed 18 feet in height from existing grade. The LMC definition also lets an Accessory Apartment be created within a detached garage. Ordinance read July 2026 | Allowed | 1,000 sq ft and no more than 1/3 of the dwelling (Accessory Apartment); no explicit size cap found (Internal ADU) | Depends on ADU type. For Internal Accessory Dwelling Units the single-family dwelling must be occupied by the owner and the unit may not be sold separately (§15-4-7.1, Ownership). No owner-occupancy requirement appears in §15-4-7 for Accessory Apartments; its deed restriction runs with the land and transfers automatically on sale. Ordinance read July 2026 | 1 space per bedroom (Accessory Apartment); 1 space per unit (Internal ADU), both in addition to the primary dwelling | Permitted use |
| Pleasant Grove | Accessory apartments are defined to include units within a detached accessory structure associated with a single-family dwelling, but only in the A-1, R-R, R-1, RM-7, DV, and Grove mixed housing zones, on owner-occupied single-family lots that can satisfy the parking requirements; tiny homes on permanent foundations may also serve as the detached accessory apartment. Ordinance read July 2026 | Units within or attached to a single-family dwelling (over the garage, in the basement, or in an addition) are allowed, but only in the A-1, R-R, R-1, RM-7, DV, and Grove mixed housing zones; no accessory apartment may be in any multi-family dwelling, and the lot must satisfy the parking requirements. Ordinance read July 2026 | no explicit size cap in the accessory apartment section | Required | 6 off-street spaces total: 4 for the main dwelling plus 2 for the accessory unit | Permitted use |
| Provo | Detached ADUs (a detached accessory structure in the rear or side yard, or a unit within one) are an allowed ADU location, but ADU use itself is only permitted in listed residential zones and is prohibited in PRO zones, R2PD, and most RM/R16 through R110 areas; west of I-15 ADUs are permitted in nearly all residential areas except SDP-5 and R2PD. Ordinance read July 2026 | Internal, over-garage, and addition ADUs are allowed in conjunction with a one-family detached dwelling, subject to the same zone eligibility: permitted use in RA, R1, R2, LDR, MDR, HDR, CMU, VLDR, RM, RC, PRO, and SDP 2-5 areas per 14.30.010(3), then carved back by 14.30.020 prohibitions (all PRO zones, R2PD, most RM/R16-R110 areas). Ordinance read July 2026 | No explicit square-footage cap; detached ADU structure must be smaller than the main dwelling in footprint and height, and no less than 200 sq ft | Required | 4 off-street spaces total for the dwelling plus ADU; two tandem spaces allowed | Permitted use |
| Salt Lake City | Allowed | Allowed | 1,000 sq ft (detached); no maximum (internal/attached) | Owner (or blood/marriage/adoption relative of a deeded owner, or family-trust trustor) must reside on the property, but owner occupancy is NOT required when the principal use is a duplex, multi-family dwelling, or non-residential use; temporary absences up to 3 years (military, job assignment, medical care) are also excepted. An owner-occupancy statement goes into a recorded restrictive covenant. Ordinance read July 2026 | 1 space, with broad waivers | Permitted use |
| Salt Lake County | Detached ADUs are a permitted use, but only on single-family home lots of 7,000 sq ft or more in areas zoned primarily for residential use (R, A, Forestry, PC zones); in the PC zone the minimum drops to 6,000 sq ft if the county has approved design standards. Not permitted in townhomes, multi-family PUDs, or other attached unit types, or on lots that cannot satisfy parking, setback, or lot coverage requirements. Ordinance read July 2026 | The code recognizes internal ADUs (IADUs) rather than attached additions: an IADU must be created within the primary dwelling and within its footprint at the time the unit is created (a garage counts if habitable and sharing a common wall). IADUs are a permitted use on single-family lots of 6,000 sq ft or more in residential zones (R, A, Forestry, PC). No category exists for an ADU added onto the house outside the existing footprint. Ordinance read July 2026 | no explicit square footage cap in the ADU chapter | Required | 1 on-site space for the ADU, in addition to the home's required parking | Permitted use |
| Sandy | Not allowed | Allowed | no explicit limit found | Required | off-street parking required | Administrative special use permit from the Community Development Department plus an accessory apartment business license (staff-level approval, not a hearing). The permit expires on sale of the property, change of the owner's residence, or business license expiration, and is not transferable. Ordinance read July 2026 |
| South Jordan | Allowed | Allowed | Guesthouse: lesser of 35% of the primary dwelling's living area or 1,500 sq ft; max 3 bedrooms | Required | 1 space | Permitted use |
| Syracuse | Detached ADUs are expressly allowed, but only in the A-1, R-1, R-2, R-3, and RPC residential zones, only on a lot with an existing (or concurrently built) single-family dwelling, and only on lots of at least 10,000 square feet; a minor conditional use permit is required. Ordinance read July 2026 | Internal (basement or attic) and attached ADUs are expressly allowed, but only in the A-1, R-1, R-2, R-3, and RPC zones on single-family lots meeting the underlying zone's minimum lot size, and a minor conditional use permit is required. Ordinance read July 2026 | 50% of principal dwelling gross sq ft (internal or attached); lesser of the main dwelling's footprint or 1,500 sq ft gross living area (detached) | Required | 1 additional off-street space (studio or one bedroom); 2 additional spaces (attached or detached with 2+ bedrooms) | A minor conditional use permit is required for every ADU. Minor conditional uses are decided administratively by the Community Development Department (no public hearing); a denial can be appealed to the Planning Commission. A building permit and a certificate of final occupancy are also required before the ADU may be occupied. Ordinance read July 2026 |
| West Bountiful | Not allowed | Allowed | No minimum or maximum size | Required | 1 additional off-street space per ADU | Permitted use |
| West Jordan | Detached ADUs (DADUs) are only permitted on platted lots of 10,000 square feet and larger in the R-1, RR, RE, PC, LSFR, and VLSFR zones; must be on a permanent foundation, footprint smaller than the primary dwelling, max height 20 feet, and design must be approved by the design review committee. Governed by this section plus Utah Code 10-21-304. Ordinance read July 2026 | Allowed | no fixed square-footage cap | Owner occupancy is not an absolute prerequisite, but it controls rental configuration: if the owner of record occupies either the primary dwelling or the ADU as a primary residence, they may rent out the other unit; if the owner occupies neither, they may rent both units together as a single unit or rent only one of the two, but may not rent both units individually at the same time (subject to Utah Code 10-21-303). Ordinance read July 2026 | 1 additional off-street space | Permitted use |
Summarized from each city's ordinance text, most recently read July 2026. Tap a value marked with an info icon to see exactly what it depends on, straight from the ordinance. Nearly every value has zone, lot-size, or process caveats beyond that; the per-city pages carry the full notes and code citations. Treat this as orientation, not a permit determination.
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Reading the table
- Detached ADU is the make-or-break column for backyard cottages: minimum lot sizes (often 8,000 to 14,500 sq ft) hide behind many of the "Allowed" values, so check your lot before celebrating.
- Attached / internal (basement apartments, additions) is legal almost everywhere and is usually the path of least resistance.
- Approval: "Permitted use" means staff-level sign-off; "Conditional use" means a public hearing, which adds time, cost, and uncertainty.
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