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2026 Cost Guide · Updated July 2026

ADU Cost in Utah — Salt Lake City, Provo, Ogden & Statewide

City-by-city ADU cost data across Utah's major markets. Built from permit records, contractor data, and regional labor rates.

$150K–$300K Detached ADU range
$60K–$140K Internal ADU (lowest cost, fastest permit)
SB284 (2026) Cities 5,000+ must now allow detached ADUs
HOA can't block Internal ADU rentals protected from HOA rules
Utah Wasatch-front modern ADU exterior
Utah ADU kitchen interior Utah ADU living room interior
At a Glance

Utah ADU costs — by type.

Detached ADU
$150K – $300K
Now protected in cities 5,000+ under SB284 (2026)
🏡
Attached ADU
$130K – $260K
Shared utility hookups reduce connection cost
🔗
Garage Conversion
$85K – $180K
Classified as attached; requires building permit
🚗
Basement Conversion (Internal ADU)
$60K – $140K
Statewide by-right protection since 2021 — fastest to permit
⬇️
Modular / Prefab
$140K – $270K
Must clear local detached-ADU review in most cities
📦
Junior ADU
$40K – $85K
A form of Internal ADU — the cheapest, most protected path
🚪
💡

Effective framework: Utah Code § 10-9a-530. State law primarily protects internal ADUs in covered areas; it should not be read as a universal detached-ADU mandate. Permit fees and review timing remain planning estimates until confirmed for the specific property.

Calculate My ROI →
ADU Types

Which type fits your property?

01 / Newly Protected
Detached ADU
$150K – $300K

A separate structure on the lot. Left entirely to city discretion until SB284 (2026) required cities with 5,000+ residents to allow them — generally needs an 11,000+ sqft lot. Confirm your city has adopted its required policy.

Detached ADU Guide →
02 / Statewide Protected
Attached ADU
$130K – $260K

A physical addition to the primary home. Attached ADUs on single-family lots have been a statewide permitted use since October 1, 2021, alongside internal ADUs.

Attached ADU Guide →
03 / Most Affordable Detached-Style
Garage Conversion
$85K – $180K

Any conversion of a garage into a habitable ADU requires a building permit and must meet current fire and safety codes — treated as attached or detached depending on whether it shares a wall with the main house.

Garage Conversion Guide →
04 / Fastest, Cheapest, Most Protected
Basement Conversion (Internal ADU)
$60K – $140K

Created within the existing home's footprint for long-term rental (30+ days). Statewide by-right protection since 2021 — and unlike most states, HOAs cannot prohibit renting an internal ADU that meets local codes.

Basement ADU Guide →
05 / Detached Category
Modular / Prefab
$140K – $270K

A factory-built unit installed on a permanent foundation, treated as a detached ADU and subject to the same city-by-city review as any other detached structure.

Prefab ADU Overview →
06 / Lowest Cost
Junior ADU
$40K – $85K

A small private suite within the existing home footprint — a form of Internal ADU carrying the same statewide by-right protection and HOA-override benefit as a basement conversion.

Junior ADU Overview →
Cost by Region

Every Utah market is different.

Salt Lake City, Utah ADU regional photo
Salt Lake City
Salt Lake County
$160K–$300K
Highest labor demand along the Wasatch Front
High
Provo, Utah ADU regional photo
Provo
Utah County · BYU area
$145K–$260K*
More affordable than Salt Lake City on average
Moderate
Ogden, Utah ADU regional photo
Ogden
Weber County
$130K–$230K*
One of the more affordable Wasatch Front markets
Affordable
Sandy, Utah ADU regional photo
Sandy
Salt Lake County · south valley
$165K–$310K*
Runs above Salt Lake City proper
High

*Total-cost ranges outside Salt Lake City are derived from regional construction-cost data at a representative ~600 sq ft build; verify against local bids before publishing final figures. St. George (warmer, drier southern Utah) and Park City (cooler mountain-resort market) are notable additional markets not pictured here — each has a distinct climate and cost profile worth checking with local contractors directly.

Cost Factors

Why Utah ADUs cost what they cost.

🏔️
Wasatch Front Labor Demand
Salt Lake City and Sandy compete for a construction labor pool stretched by rapid population growth along the Wasatch Front. Provo and Ogden run meaningfully more affordable than the Salt Lake core.
Premium in Salt Lake City & Sandy
📐
Internal vs. Detached Regulatory Split
Because only internal/attached ADUs carry statewide by-right protection, detached ADU projects still face genuine city-by-city discretion, even after SB284 — adding uncertainty and design-review cost that internal conversions avoid.
Detached projects face more design-review risk
🅿️
Parking & Lot-Size Requirements
Cities may require one additional off-street parking space for an internal ADU and can restrict them on lots under 6,000 sqft. Detached ADUs under SB284 generally need an 11,000+ sqft lot — a real constraint on smaller urban parcels.
Can eliminate certain lots entirely
⚖️
Current ADU Legal Framework
State law primarily protects internal ADUs in covered areas; it should not be read as a universal detached-ADU mandate.
Effective framework · Utah Code § 10-9a-530
Homeowners reviewing ADU permit documents in Utah
Permits & Fees

What permitting actually costs.

State law primarily protects internal ADUs in covered areas; it should not be read as a universal detached-ADU mandate. The detailed figures below are representative planning ranges, not a statewide fee schedule or review-time guarantee.

✏️
Design Fees
$5,000 – $15,000
Architectural drawings, structural plans, energy compliance documentation.
📄
Permit Fees
$1,000 – $5,000
Varies by municipality and project scope.
🏛️
Historic District Certificate of Appropriateness
$200 – $800
Required in historic districts, in addition to standard permitting.
🅿️
Additional Off-Street Parking
$2,000 – $8,000
Cities may require one additional space for an internal ADU.
🧾
Rental License / Registration
Varies by city
Many cities require a permit or license to legally rent an internal ADU.
Verified August 5, 2026 · Effective framework
Utah Code § 10-9a-530

State law primarily protects internal ADUs in covered areas; it should not be read as a universal detached-ADU mandate.

Legal classificationEffective framework
Governing frameworkUtah Code § 10-9a-530
Representative permit fees$1,000 – $5,000
Representative review timeVerify locally
Local verificationRequired

Source: Utah Legislature — § 10-9a-530 →

Verify the property before design

These are planning benchmarks, not a permit quote, eligibility ruling, or legal opinion. Confirm zoning, building, utility, site, private-covenant, fee, and timing requirements with the current local authorities. See the 51-jurisdiction law directory and national permit guide.

Return on Investment

Utah ROI planning inputs.

$1,125–$1,750
Adopted statewide 1-bedroom rent range
15%
National property-value planning input
10%–20%
Property-value uncertainty range
30%
Operating-expense planning reserve
Rent source
HUD FY2026 revised
One-bedroom FMR market basket
Exact HUD mappings
ROI-CM-1.4
Home-value source
Statewide Zillow ZHVI
June 30, 2026
One statewide input
Not a valuation
Payback period
Calculated live
Budget, ADU type, size and rent
Open calculator →
No static statewide promise
Full methodology
Transparent sources
HUD, Census PUMS, Zillow and FHFA
Review methodology →
Planning estimate, not a valuation
Save Money

7 ways to cut your
Utah ADU cost now.

Internal ADUs already carry the strongest statewide protection. These moves help you decide which track — internal or detached — actually fits your budget and timeline.

Calculate My ADU ROI →
Compact detached ADU exterior with Wasatch-front landscaping
🏡
Compact Detached ADU
Utah — statewide range
Property-Value Planning Input
15%
1
Default to an internal ADU unless your lot really calls for detached
Internal/attached ADUs skip conditional-use review entirely and carry an HOA override most other states don't offer. Unless you specifically need a freestanding structure, this is the fastest and cheapest path.
Skips conditional-use approval; often 40–60% cheaper
2
Confirm your city's SB284 compliance status before planning a detached ADU
Cities have until October 2026 to adopt a compliant detached-ADU ordinance. Some are ahead of schedule, others are still drafting — check before you invest in a detached-specific design.
Free — avoids designing for a policy that isn't final yet
3
Check your lot size against the 6,000 sqft and 11,000 sqft thresholds
Cities may restrict internal ADUs on lots under 6,000 sqft, and detached ADUs under SB284 generally need 11,000+ sqft. Knowing which category your lot falls into early avoids wasted design work.
Free — avoids paying for an infeasible design
4
Convert a garage with the interior door sealed off
One of the more cost-efficient paths available, especially in Ogden and Provo where existing housing stock includes many detached garages suitable for conversion.
Saves 35–50% vs. new construction
5
Verify whether your city still requires owner-occupancy
HB 82 removed the statewide owner-occupancy mandate for internal ADUs, but many cities kept their own requirement. Confirming this before you plan a rental strategy avoids a legal problem down the line.
Prevents a compliance issue after move-in
6
Budget for the rental license or permit your city requires
Many Utah cities require a rental license or registration to legally rent an internal ADU. This is inexpensive but easy to miss — factor it into your project timeline from the start.
Avoids fines for operating without registration
7
Remember internal ADUs are long-term rentals only
State law defines Internal ADUs as rentals of 30+ consecutive days, which excludes short-term/nightly rentals. Don't build your ROI case around Airbnb income for an internal ADU.
Prevents overestimating rental income
Frequently Asked Questions

Utah ADU answers.

Does Utah have a statewide ADU law?
Utah Code § 10-9a-530 is classified as an effective statewide or district framework in NationwideADU's August 5, 2026 review. State law primarily protects internal ADUs in covered areas; it should not be read as a universal detached-ADU mandate. Local zoning, building, utility, site, and private-covenant requirements may still apply; verify the current rules for the property before design or construction.
Can my HOA block my Utah ADU?
For internal ADUs, no — where an internal ADU would not violate local zoning or building, health, or fire codes, state law says renting it may not be prohibited by any private community association CC&R or HOA rule. This is different from most other states, where HOA covenants are generally not preempted by ADU laws. Detached ADUs don't carry this same statewide HOA override.
Do I have to live on my property to rent an internal ADU in Utah?
HB 82 removed the statewide owner-occupancy mandate for internal ADUs, but it did not forbid cities from keeping their own owner-occupancy condition. Many Utah cities still require the owner to reside in the primary home or the ADU for at least six months per year — confirm with your specific city.
Can I rent my Utah internal ADU on Airbnb?
No. State law defines an Internal ADU specifically as a unit offered for long-term rental of 30 consecutive days or longer, which excludes short-term or nightly rentals by definition — not just by local ordinance.
What is the cheapest ADU to build in Utah?
An internal ADU — a basement or interior conversion within the existing home's footprint — is typically the cheapest and fastest-permitted option statewide, commonly $60,000–$140,000 depending on finish level.
Can I build a detached ADU anywhere in Utah?
Not automatically. Detached ADUs depend entirely on your city's ordinance. SB284 (2026) now requires cities with 5,000+ residents to permit them, generally on lots of 11,000+ sqft, with an October 2026 compliance deadline — but the precise contours vary city to city and continue to be revisited by the legislature.
Why does Sandy rent for more than Salt Lake City?
Sandy and other south-valley Salt Lake County suburbs consistently post higher average rents than Salt Lake City proper, often exceeding $1,700/month for a 1-bedroom — a genuine, sourced market condition tied to newer housing stock and suburban demand.
What is the ROI on an ADU in Utah?
The adopted Utah one-bedroom planning range is $1,125–$1,750 per month, derived from the HUD FY2026 revised FMR market basket under ROI-CM-1.4. Payback is calculated from the homeowner's budget, ADU type, size, rent range, and a 30% operating-expense reserve. Property value uses a 15% national planning input with a 10%–20% uncertainty range; it is not a valuation.
Utah ADU exterior at blue hour, warm interior light glowing
Imagine coming home to your own Utah ADU.

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Planning Disclaimer: Cost, fee, and timeline ranges are approximations for education and early planning; actual requirements and costs vary with the property, local authority, utilities, site conditions, design, and contractor. The Utah legal classification and framework shown here were verified on August 5, 2026, but they do not determine parcel eligibility and are not legal advice. Confirm current zoning, building, utility, private-covenant, fee, and timing requirements directly with the applicable authorities before design or construction. Obtain at least three contractor bids before committing to a project budget. Last updated August 2026.