Utah cities must allow detached ADUs; associations need not
Utah cities must allow detached ADUs; associations need not
2026-09-19 · Utah · Legislation
From October 1, 2026, a Utah municipality above the statutory population threshold has to permit a detached accessory dwelling unit on a single-family lot of 11,000 square feet or more. The mandate reaches the zoning code. It does not reach the declaration.
S.B. 284 is a 121-page land-use omnibus, signed in the 2026 session and mostly effective May 6, 2026, with the detached-ADU mandate at new Utah Code § 10-21-304 carrying its own later date.1 The operative sentence:
“A specified municipality shall adopt a land use regulation that permits a detached accessory dwelling unit on any lot or parcel that is 11,000 square feet or larger and contains a single-family dwelling, if the single-family dwelling is a permitted use on the lot or parcel.”
The distinction the bill does not blur
Section 10-21-304 sits in Title 10, the municipalities title. The bill does not amend Title 57 — not the Community Association Act, not the Condominium Ownership Act — and contains no clause addressing private covenants. Its own savings provision at (5) is written in municipal-code terms: the section does not supersede a regulation of a detached accessory building that is not an ADU, prohibitions in a development agreement signed on or before May 6, 2026, or “a land use regulation or administrative action that: (i) is not prohibited by law; and (ii) relates to a detached accessory dwelling unit.”
Where Utah has overridden covenants on ADUs
The state has done it, twice, and both times explicitly in Title 57 — and both times only for internal accessory dwelling units, the kind built inside an existing home.
Section 57-8a-218(16) governs construction:
“(a) Except as provided in Subsection (16)(b), a rule may not prohibit the owner of a residential lot from constructing an internal accessory dwelling unit, as defined in Section 10-21-101 or 17-80-101, within the owner's residential lot. (b) Subsection (16)(a) does not apply if the construction would violate: (i) a local land use ordinance; (ii) a building code; (iii) a health code; or (iv) a fire code.”
Section 57-8a-209(10) governs renting one out:
“Notwithstanding Subsection (1)(a), an association may not restrict or prohibit the rental of an internal accessory dwelling unit…constructed within a lot owner's residential lot, if the internal accessory dwelling unit complies with all applicable: (a) land use ordinances; (b) building codes; (c) health codes; and (d) fire codes.”
The Department of Commerce states the position plainly on its own HOA guidance page: associations “may not enact or enforce…a provision that prohibits a lot owner from constructing an [internal ADU],” while detached units remain subject to association prohibition.2 Our Utah ADUs and modifications page sets out the whole structure.
The gap this leaves an owner in
An owner on a 12,000-square-foot lot in a qualifying municipality, inside an association whose declaration bans detached accessory structures, is in a position the statutes now describe from both directions: the city must permit the use, and the association is not told to. Two permissions are required to build and only one of them was legislated.
The internal-ADU route is the one Title 57 opens, and it is a genuinely different construction project — conversion within the existing dwelling envelope, not a second building.
The condominium chapter has neither provision
Worth noting for anyone reading across: the Condominium Ownership Act contains no parallel to § 57-8a-218(16) and no parallel to § 57-8a-209(10). The rental-restriction section for condominiums, § 57-8-10.1, was itself amended in the 2025 session and still carries no ADU carve-out. The ADU protections Utah has enacted reach planned communities, not condominiums. Our Utah short-term rentals page covers the rental-restriction machinery on both sides of that line.
The timing
October 1, 2026 is also the date two other association-facing provisions arrive: the new consolidation sections at § 57-8a-601 and § 57-8-55, and the standardized business-entity filing framework in new Title 16, Chapter 1a, which reaches every association incorporated as a Utah nonprofit.3 It is a busy date on the Utah calendar.
What to watch next
Municipalities without an existing ADU ordinance face their own adoption deadline this autumn, so the first round of local ordinances lands before the 2027 session opens in January. Whether the legislature closes the covenant gap for detached units is a live question for that session: the state's HOA ombudsman convened a working group in April 2026 to develop recommendations, with housing affordability named among the drivers.4
Related Utah HOA Topics
- S.B. 284, Local Land and Water Modifications, 2026 General Session (enrolled copy) ↩
- Accessory dwelling units, Office of the Homeowners' Association Ombudsman, Utah Department of Commerce ↩
- S.B. 40, Business Entity Amendments, 2026 General Session (enrolled copy) ↩
- Utah Office of the Homeowners' Association Ombudsman establishes working group (April 23, 2026) ↩
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