ADU Builders in Utah (2026): 9 Builders and Designers Compared by Service Area, ADU Type, and Published Price

Who builds ADUs in Utah?

Answer: In Utah, ADUs are built by a handful of design-build ADU specialists, local general contractors, and architects with pre-approved plans. Nest Tiny Homes has a Salt Lake City office and publishes Utah model pricing. Royal Blue Build (Utah County), Riven Homes (Wasatch Front and Heber Valley), Grandview Contractors, and Oakley Homes & Construction build ADUs as part of broader residential work.

Here's the fit table. Every cell comes from the firm's own website or Salt Lake City's pre-approved plans page, read on November 9, 2026. “Not stated” means we didn't find it on their site, not that they don't do it.

Sources: each firm's website and Salt Lake City's “ADU Pre-Approved Standard Plans” page, read November 9, 2026. Prices are the firms' published figures, not quotes. Nest Tiny Homes is an affiliate partner; we may earn a commission at no extra cost to you.

Two things stand out. First, only three of the nine publish any price at all. Second, the architects on the SLC list design plans; they don't build. You'd still need a licensed contractor to build their plan.

Which Utah ADU builder fits your project?

Answer: Pick the builder type that matches your ADU type. For a detached new build with known pricing, a design-build ADU firm is simplest. For a basement or garage conversion, a local contractor that lists that work is usually a better fit. For speed in Salt Lake City, use a pre-approved plan.

Detached backyard ADU, you want one contract.

A design-build firm handles design, permits, and construction under one roof. Nest Tiny Homes describes this process: a discovery call, a site assessment, financing through lending partners, an in-house architect, and a permitting service it calls “Permit Flow.” The trade-off is that you're choosing from their models (with customization), not a blank sheet.

Basement apartment (internal ADU).

Basement apartments are a common Utah ADU type, in part because internal ADUs have been a permitted use in residential zones statewide since 2021. Basement work is mostly egress windows, fire separation, a kitchen, and sometimes a separate entrance. Riven Homes lists basement ADUs. Ask any contractor how many basement egress cuts they've done and which city inspectors they've worked with.

Garage conversion.

Riven Homes and Nest Tiny Homes both list garage conversions. If you're in Salt Lake City, two architects (Brach Design and LMnt) have pre-approved garage-conversion plans, including a second-story option.

Custom detached ADU in Utah County.

Royal Blue Build publishes a per-square-foot range for Utah County. Grandview Contractors lists Utah County and the Salt Lake Valley.

What do Utah ADU builders charge?

Answer: Published Utah ADU prices on November 9, 2026, ranged from Riven Homes' “starting at $97,000” to Nest Tiny Homes' $276,083 for a 1,000-sq-ft model. Royal Blue Build cites $190–$350 per square foot. Nest's Utah models work out to $276–$617 per square foot; smaller units cost more per foot.

Nest Tiny Homes publishes the most detail, so we converted its Utah model list to price per square foot:

Source: Nest Tiny Homes Utah models page, read November 9, 2026. “Starting at” prices are not quotes; ask in writing what's excluded (site work, utility trenching, sewer lateral, permit and impact fees, upgrades). Price per square foot is our arithmetic. Nest Tiny Homes is an affiliate partner; we may earn a commission at no extra cost to you.

Here's how to compare a $/sq ft quote against a “starting at” model price. Royal Blue Build's $190–$350 per sq ft range, applied to a 600-sq-ft ADU, is $114,000–$210,000. That's our arithmetic, not their quote, and it may not include the same items as a design-build model price. The only fair comparison is two written quotes for the same size, same site, with the same list of inclusions.

Utah-specific cost items to ask about:

• Impact fees. For an internal ADU, a Utah city can't charge an impact fee (Utah Code § 11-36a-202). Detached ADUs aren't covered by that bar, so ask your city.
• Parking. Under § 10-21-304, a city can require at most one parking space for a detached ADU under 650 sq ft and two for 650 sq ft or more. A second space can mean extra concrete.
• Sewer and water. Ask whether the quote includes a new sewer lateral or a tie-in to the existing one, and the utility district's connection fees.
• Frost depth and snow load. Utah foundations and roofs are designed for local frost depth and snow loads, which vary by elevation. Mountain lots (Summit, Wasatch) can cost more.

For a full cost breakdown, see our Utah ADU laws guide and ADU cost guide.

Which builders have Salt Lake City pre-approved ADU plans?

Answer: Salt Lake City's pre-approved ADU standard plans list includes Built By Design Construction (plan A3, 650 sq ft, 1 bedroom), Brach Design Architecture (detached garage conversion), Nest Tiny Homes (plan 2B-775, 775 sq ft, 2 bedrooms), LMnt Architecture (second-story detached garage conversion), and ADU America (Unit 800, 800 sq ft, 2 bedrooms).

A pre-approved plan has already been reviewed for building-code compliance. That can shorten plan review. It doesn't skip it entirely. The city still reviews your site plan (setbacks, utilities, lot coverage) and issues a building permit, and normal fees still apply.

Source: Salt Lake City “ADU Pre-Approved Standard Plans” page, read November 9, 2026. The city adds plans over time; check the page for the current list.

Two caveats. Salt Lake City caps a detached ADU at 1,000 sq ft of gross floor area and requires owner occupancy, with limited exceptions. And an 800-sq-ft plan triggers the two-space parking ceiling under state law if the city requires parking.

Utah ADU builder profiles

Nest Tiny Homes (Salt Lake City)

Best for: Homeowners who want a detached ADU from a published model list, with design and permits handled in-house.

Nest Tiny Homes is an ADU design-build company with a Utah office at 4190 South Highland Drive, Suite 114, Salt Lake City, UT 84124, and phone (801) 903-2219. It lists detached ADUs, attached ADUs, and garage conversions. Its Utah regulations page covers Box Elder, Cache, Davis, Morgan, Rich, Salt Lake, Summit, Tooele, Utah, Wasatch, and Weber counties.

What its site says about the process: a discovery call, a site assessment, financing options through lending partners, an in-house architect, and a “Permit Flow” permitting service. It's also on Salt Lake City's pre-approved plans list with plan 2B-775.

What to check: The footer shows a California contractor license (CSLB #1131365). We didn't see a Utah DOPL license number on the pages we read. Ask for it, and look it up before you sign.

Royal Blue Build (Utah County)

Best for: Custom ADUs between Orem and Lehi.

Royal Blue Build serves Utah County and publishes an ADU cost range of $190–$350 per square foot and a 5–8 month timeline. It's a general contractor rather than an ADU-only firm. Ask whether the range includes design, permits, and utility work.

Riven Homes (Wasatch Front and Heber Valley)

Best for: Basement and garage ADUs, and smaller budgets.

Riven Homes lists detached, garage, and basement ADUs across the Wasatch Front and Heber Valley, with ADUs “starting at $97,000” and a 4–7 month timeline. A “starting at” figure usually reflects the simplest project, often a conversion. Get the scope in writing.

Grandview Contractors (Utah County and Salt Lake Valley)

Best for: Homeowners who want to see a license number up front.

Grandview Contractors serves Utah County and the Salt Lake Valley. Its site shows a Utah DOPL B100 (general building contractor) license, #14282236-5501. It doesn't publish ADU prices.

Oakley Homes & Construction (Salt Lake, Utah, Davis, Weber)

Best for: Homeowners in Davis or Weber County, where fewer ADU firms advertise.

Oakley Homes & Construction lists ADU work in Salt Lake, Utah, Davis, and Weber counties. It doesn't publish ADU prices.

Salt Lake City pre-approved plan firms

Built By Design Construction, ADU America, Brach Design Architecture, and LMnt Architecture each have a plan on SLC's pre-approved list. Built By Design Construction and ADU America's plans are detached new builds. Brach Design and LMnt are architecture firms with garage-conversion plans. If you use an architect's plan, you'll still hire a licensed general contractor to build it.

What's the catch with Utah ADU builders?

Answer: The catch is that most Utah ADU builders don't publish full prices, and “starting at” figures exclude things. Utah's detached-ADU market is also new: the statewide detached-ADU mandate only took effect October 1, 2026, so few builders have a long track record with the new city ordinances.

Here's what we'd tell a friend:

• “Starting at” isn't a quote. Site work, utility trenching, sewer laterals, and permit and impact fees often sit outside the base price.
• Track records are short. Basement ADUs have been permitted statewide since 2021. Detached ADUs on most 11,000-sq-ft lots have only been mandatory since October 1, 2026, and each city is writing its own rules.
• Some firms are new to Utah. A firm can have years of experience in another state and fewer Utah projects. Ask for Utah addresses you can drive by.
• We didn't include everyone. This list covers firms whose websites we could read and verify on November 9, 2026. We left out firms we couldn't verify.

How do you vet a Utah ADU builder?

Answer: Look up the contractor's license on the Utah Division of Professional Licensing (DOPL) website, confirm it's active and the right classification, ask for proof of liability and workers' comp insurance, get references from Utah ADU projects, and compare two or three written, line-item quotes for the same scope.

Step 1: Check the license. In Utah, contractors are licensed by DOPL, part of the Utah Department of Commerce. Use DOPL's online license lookup to confirm the license is active and matches the work. A general building (B100) or residential and small commercial (R100) license is typical for a new ADU. Specialty trades have their own classifications.

Step 2: Ask these 10 questions.

1. What's your Utah DOPL license number and classification?
2. How many ADUs have you finished in my city, and can I see one?
3. Is design included, or do I hire an architect?
4. Who pulls the permit, and who deals with plan-review comments?
5. What's excluded from this price? (Site work, sewer lateral, utility connection fees, impact fees, landscaping, appliances.)
6. How do you handle frost depth, snow load, and soil conditions on my lot?
7. What's the payment schedule, and is any payment due before the permit is issued?
8. What's your realistic timeline, start to certificate of occupancy?
9. What warranty do you give, in writing?
10. Who's my day-to-day contact during construction?

Step 3: Compare apples to apples. Ask each builder to price the same size and the same inclusions. Put the quotes side by side, line by line.

Before you call anyone, know what your lot allows. Builders quote faster and more accurately when you already know your lot size, zoning, and whether your city's ordinance allows the unit you want.

How long does it take to build an ADU in Utah?

Answer: Utah builders publish timelines of about 4 to 8 months: Riven Homes cites 4–7 months and Royal Blue Build cites 5–8 months. Add time for design and permitting before construction, which varies by city.

A typical sequence:

1. Feasibility and design (lot check, survey, plans): several weeks.
2. Permitting: depends on your city's workload and whether you use a pre-approved plan.
3. Construction: the 4–8 month window builders publish.
4. Final inspection and certificate of occupancy.

Utah winters matter. Foundations are easier to pour before the ground freezes, so a spring or summer start is common for detached ADUs. Interior basement work can run year-round.

What Utah ADU rules do builders have to work within?

Answer: Builders work within Utah Code § 10-21-303 (internal ADUs are a permitted use in residential zones), § 10-21-304 (most cities must allow detached ADUs on lots of 11,000 sq ft or more since October 1, 2026), and your city's own ordinance on size, height, setbacks, parking, and owner occupancy.

A good Utah ADU builder knows your city's ordinance before quoting. A quick test: ask what your city's maximum detached ADU size and height are. For the full rulebook, including what cities can and can't require, read our Utah ADU laws guide.

How do Utah homeowners pay for an ADU?

Answer: Most Utah homeowners pay for an ADU with cash, a home equity loan or HELOC, a cash-out refinance, or a renovation or construction loan. FHA rules also let lenders count some projected ADU rent toward qualifying income in certain cases.

We cover the options in detail in our ADU financing guide and our page on whether ADU rental income can help you qualify for a mortgage.

Methodology

We searched for Utah ADU builders on Google and Bing, read Salt Lake City's pre-approved plans page, and then read each firm's own site. We recorded only what each firm states. Where a firm publishes a model price list, we calculated price per square foot. We ordered the profiles by how much verifiable information each firm publishes, not by quality. We'll re-check this page quarterly.

Sources

• Utah Code § 10-21-303, § 10-21-304, § 11-36a-202 — le.utah.gov (read November 9, 2026)
• Salt Lake City, “ADU Pre-Approved Standard Plans” — slc.gov (read November 9, 2026)
• Nest Tiny Homes, Utah ADU models and Utah regulations pages (read November 9, 2026)
• Royal Blue Build, Riven Homes, Grandview Contractors, Oakley Homes & Construction websites (read November 9, 2026)
• Utah Division of Professional Licensing (DOPL), license lookup

Frequently asked questions