Utah
Utah passed statewide ADU legislation requiring municipalities to allow internal accessory dwelling units, and Salt Lake City has extended that to detached ADUs as well. The state's rapid growth and housing affordability challenges make ADUs an important part of the solution. ADU Pass helps Utah homeowners handle the permit paperwork.
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State ADU details
State ADU law
Utah preempts municipal and county zoning for INTERNAL accessory dwelling units (IADUs) — ADUs created within the footprint of an owner-occupied primary single-family dwelling for long-term (30+ day) rental. Under HB 82 (2021), IADUs are a PERMITTED use by right in any area zoned primarily for residential use, codified at Utah Code §§ 10-9a-530 (municipalities) and 17-27a-526 (counties). Local governments may opt out of the requirement in zones covering up to 25% of the area zoned primarily for residential use (or 67% in cities with a university and a student population of 10,000+). Internal ADUs are also exempted from impact fees by Utah Code § 11-36a-202. The state has NOT yet preempted DETACHED (external) ADU regulation — those remain a local-zoning question. Multiple 2025 bills (Rep. Ray Ward's HB 88 / HB 90) that would have extended preemption to detached ADUs and small-lot single-family units stalled in the House Political Subdivisions Committee. SB 284 (2026) advanced a narrower detached-ADU allowance limited to lots 11,000 sqft or larger.
State HOA preemption
Utah's HOA preemption is narrower than California's AB 3182. It targets only IADUs and splits the analysis: rental restrictions are fully voided (rules and CC&Rs alike); construction restrictions are voided only at the rule level, leaving CC&Rs enforceable. Detached ADUs are entirely outside the preemption — an HOA can ban detached ADUs by rule or CC&R without conflict with state law.
State financing programs
Utah's primary state housing finance vehicle is the Olene Walker Housing Loan Fund (OWHLF), administered by the Department of Workforce Services Housing & Community Development Division under Utah Code Title 35A Chapter 8 Part 5. OWHLF historically funds gap financing for affordable multifamily projects and preservation of affordable units; it is not consumer-facing for individual ADU construction loans. HB 82 (2021) directed the creation of an IADU-specific incentive/loan program but the vehicle has not been heavily capitalized as a standalone consumer loan; in practice, IADU financing is delivered through conventional renovation/cash-out-refinance products from Utah Housing Corporation (the state's housing finance agency) and from credit unions and banks. UHC offers FirstHome and HomeAgain loan programs that can be combined with rehab financing for IADU work as part of a primary-residence purchase or refinance, but UHC has no dedicated 'ADU loan' product.
State insurance regimes
Utah has NO FAIR Plan and NO state-run wildfire insurance pool. Property insurance is regulated by the Utah Insurance Department; admitted carriers and surplus lines write the residential market. Wildfire risk is the dominant ADU-relevant insurance issue: Utah enacted HB 48 (2025 — Wildland Urban Interface Modifications) requiring property insurers to use the state's High-Risk Wildland-Urban Interface boundary map (wildfirerisk.utah.gov) when underwriting wildfire risk, and requiring 60+ days' written notice with justification when a carrier raises rates 20%+ or non-renews due to wildfire risk. HB 48 also created a Wildfire Mitigation Fee ($20–$100/yr per taxable structure inside the high-risk WUI boundary) to fund the state's Wildfire Preparedness Program; approximately 60,000 structures are inside the fee area. Utah is not a hurricane state and has no wind-pool framework; flood coverage is via FEMA NFIP for property in mapped SFHAs. ADUs follow the primary dwelling's wildfire and flood ratings — there is no separate ADU underwriting class.
State housing programs
Utah has NO statewide pre-approved ADU plan library (some individual cities — notably Salt Lake City — publish a city-level pre-approved plan set). The state's main ADU-relevant statewide program is the IMPACT-FEE EXEMPTION for internal ADUs under Utah Code § 11-36a-202 (added by HB 82, 2021) — every municipality and county is barred from charging impact fees for an IADU. The second statewide framework is the MODERATE INCOME HOUSING PLAN (MIHP) requirement under HB 462 (2022) and follow-on bills, which forces every Utah city and county to adopt a MIHP from a menu of housing-supply strategies; allowing/encouraging ADUs is one of the menu items, so MIHP indirectly nudges local ADU policy without directly preempting it. There is no statewide ADU rebate or grant program comparable to CalHFA's. Streamlined-review timelines for IADUs are implicit in the HB 82 permitted-use classification — IADUs cannot require conditional-use review and must move on the standard ministerial-permit timeline.
- Statewide IADU Impact-Fee Exemption — By statute, no Utah municipality or county may charge impact fees for an internal accessory dwelling unit. This is a hard statewide preemption of impact fees in the IADU context, not a discretionary local waiver.
- Statewide Permitted-Use Classification for IADUs (de facto streamlined-review mandate) — By making IADUs a permitted use rather than a conditional use, HB 82 removed the discretionary public-hearing review pathway. IADU permits are processed ministerially against the limited list of statutorily-allowed restrictions. Effectively eliminates the 60–120-day conditional-use overlay that pre-2021 IADU permits typically carried.
- Moderate Income Housing Plan (MIHP) Statute — Every Utah city and county must adopt and implement a Moderate Income Housing Plan from a menu of housing-supply strategies; allowing/encouraging ADUs is one menu item. DWS Housing administers the reporting framework. Non-compliance can affect transportation funding eligibility under follow-on legislation.
Known state issues (3)
- legislative-session (since 2025-02-12) — As of the 2026 session, detached ADUs remain a local-zoning question for the majority of Utah residential lots (those under 11,000 sqft). Internal ADUs are fully preempted; detached ADUs are only narrowly preempted. Practitioners should verify each city's detached-ADU ordinance independently of the state IADU framework.
- policy-review (since 2025-05-01) — ADU underwriting in WUI-classified parcels is increasingly expensive. The HB 48 disclosure right gives owners a documented basis to challenge rate actions, but the underlying risk assessment and mitigation fee remain. Buyers and ADU-builders should pull the parcel's WUI classification before estimating insurance carrying cost.
- other (since 2021-10-01) — In master-planned communities along the Wasatch Front (Daybreak, Eagle Mountain, Lehi growth areas), recorded CC&Rs commonly prohibit any accessory dwelling. State preemption does not override those CC&Rs for IADU construction or for any detached ADU. The practical effect is that a meaningful fraction of newer subdivision lots cannot host an ADU regardless of state law.
Federal (United States) — ADU-relevant rules and programs
Federal ADU law
The United States has no federal statute that directly regulates accessory dwelling unit entitlement or design. Land-use authority over ADUs resides with states and local governments under the traditional police power. Federal engagement is limited to financing (Fannie/Freddie/FHA/VA/USDA), flood insurance (FEMA/NFIP), and discretionary housing programs (HUD), which are recorded in sibling sections of this file.
Federal financing programs
Federal housing-finance agencies and GSEs set nationwide underwriting rules that govern whether an ADU can be financed, appraised, and counted toward mortgage qualifying income. The relevant actors are Fannie Mae, Freddie Mac, FHA (HUD), VA, and USDA Rural Development.
Federal tax credits
There is no ADU-specific federal tax credit. ADUs may incidentally qualify for existing federal energy-efficiency and clean-energy tax credits when the ADU construction includes qualifying measures.
Federal housing programs
HUD administers several discretionary programs that can fund ADU-related activity at the grantee's election, but none is an ADU-specific program.
Counties
- Beaver County
- Box Elder County
- Cache County
- Carbon County
- Coconino County
- Daggett County
- Davis County
- Duchesne County
- Emery County
- Garfield County
- Grand County
- Iron County
- Juab County
- Kane County
- Millard County
- Morgan County
- Piute County
- Rich County
- Salt Lake County
- San Juan County
- Sanpete County
- Sevier County
- Summit County
- Tooele County
- Uintah County
- Utah County
- Wasatch County
- Washington County
- Wayne County
- Weber County
Cities
- Alta
- Altamont
- Alton
- American Fork
- Aneth
- Annabella
- Antimony
- Aurora
- Bear River City
- Beaver
- Bicknell
- Big Water
- Bingham Canyon
- Blanding
- Bluebell
- Bluff
- Boulder
- Bountiful (Davis County)
- Bountiful (No County)
- Brian Head
- Brigham City (Box Elder County)
- Brigham City (Cache County)
- Bryce Canyon City
- Cannonville
- Castle Dale
- Cedar City (Iron County)
- Cedar City (Kane County)
- Cedar City (Washington County)
- Cedar Valley
- Centerville
- Circleville
- Clarkston
- Clearfield (Davis County)
- Clearfield (No County)
- Cleveland
- Coalville
- Corinne
- Delta
- Draper
- Duchesne
- Dugway
- Dutch John
- East Carbon
- Echo
- Eden
- Elberta
- Elmo
- Elsinore
- Emery
- Enterprise
- Ephraim
- Escalante
- Eureka
- Fairview
- Farmington
- Ferron
- Fielding
- Fillmore
- Fort Duchesne
- Fountain Green
- Garden City
- Garland
- Garrison
- Glendale
- Glenwood
- Goshen
- Grantsville
- Green River (Emery County)
- Green River (Grand County)
- Grouse Creek
- Gunnison
- Hanksville
- Hatch
- Heber City
- Helper
- Henefer
- Henrieville
- Hill Air Force Base
- Hinckley
- Holden
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- Huntington
- Huntsville
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- Jensen
- Junction
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- Kanab
- Kanosh
- Kaysville
- Koosharem
- La Sal
- La Verkin
- Lake Powell
- Laketown
- Lapoint
- Layton
- Leamington
- Leeds
- Lehi (No County)
- Lehi (Utah County)
- Levan
- Lewiston
- Loa
- Logan (Cache County)
- Logan (No County)
- Lyman
- Lynndyl
- Magna
- Manila
- Manti
- Marysvale
- Mayfield
- Meadow
- Mendon
- Mexican Hat
- Midvale
- Midway
- Milford
- Millville
- Minersville
- Moab
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- Montezuma Creek
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- Morgan
- Moroni
- Mount Pleasant
- Myton
- Navajo Mountain
- Neola
- Nephi
- New Harmony
- Newcastle
- Newton
- North Salt Lake
- Oak City
- Oakley
- Ogden (No County)
- Ogden (Weber County)
- Orangeville
- Orderville
- Orem
- Panguitch
- Paradise
- Paragonah
- Park City (No County)
- Park City (Summit County)
- Park Valley
- Parowan
- Payson
- Pleasant Grove
- Plymouth
- Price
- Providence
- Provo (No County)
- Provo (Utah County)
- Randolph
- Redmond
- Richfield (Piute County)
- Richfield (Sevier County)
- Richmond
- Riverside
- Riverton
- Rockville
- Roosevelt
- Roy
- Rush Valley
- Saint George (No County)
- Saint George (Washington County)
- Salem
- Salina
- Salt Lake City (No County)
- Salt Lake City (Salt Lake County)
- Sandy (No County)
- Sandy (Salt Lake County)
- Santa Clara
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- South Salt Lake (Salt Lake County)
- Spanish Fork
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- Vernal (No County)
- Vernal (Uintah County)
- Vernon
- Veyo
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- Washington
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- Wellsville
- Wendover
- West Jordan
- West Valley City (No County)
- West Valley City (Salt Lake County)
- Whiterocks
- Willard
- Woodruff