Utah Accessory Dwelling Unit Builders — Build Granny Flats & Backyard Cottages
Utah's independent ADU planning resource. Check zoning, estimate costs, and get matched with a vetted builder for your in-law suite, granny flat, or backyard rental unit.
Detached ADU
Varies by size and features
Standalone backyard cottage, ~400–800 sq ft
Avg. timeline: 7–12 months
Garage Conversion
Cost-effective conversion option
Converting an existing or new garage
Avg. timeline: 5–9 months
Garage conversion ADU guide →Basement ADU
Budget-friendly approach
Adds separate entrance, egress, kitchens/baths
Avg. timeline: 4–8 months
Prices are typical turnkey ranges for 2025 and vary by size, sitework, utilities, and finishes. Get a property-specific quote.
2026 Utah detached ADU law update (SB 284)
Utah SB 284 created Utah Code §10-21-304, effective October 1, 2026. In a "specified municipality," cities must allow one detached ADU on lots or parcels of 11,000 square feet or larger where a single-family home is allowed, and cities may allow detached ADUs on smaller lots. Cities may still regulate size, height, setbacks, lot coverage, design compatibility, utility capacity, owner-occupancy, front-yard placement, short-term rental use under 90 days, and whether more than one ADU is allowed. Local permits and building, fire, utility, and health-code review still apply.
Accessory Dwelling Unit Cost in Utah (2025): Key Factors That Drive Your Budget
In Utah, ~5 inputs drive 80% of your ADU budget. Focus here first for the biggest savings:
Size & layout
Square footage and number of kitchens/baths.
Foundation & structure
Slab vs. crawlspace; new vs. conversion.
Utilities
Distance and difficulty to run sewer/water/power/gas.
Sitework
Grading, access, setbacks, and drainage.
Finish level
Cabinetry, tile, windows, HVAC, insulation.
How Utah ADU Hub Works
Tell us about your property
Lot size, utilities, zoning, and your goals (rental, family, office).
Get matched with a vetted builder
You get matched with professional ADU pros who fit your scope, budget, and city rules.
Compare bids & timelines
Side-by-side pricing with the same assumptions so you can choose with confidence.
Do I need a permit for an ADU in Utah?
Yes—most ADUs in Utah require a building permit (and often a zoning or planning review). The exact rules depend on your city, lot, and ADU type (detached, garage conversion, or basement). Typical submittals include a site plan with setbacks, architectural drawings, structural and energy compliance, and utility plans.
Salt Lake City quick take
Salt Lake City has specific standards for internal, attached, and detached ADUs (e.g., height, size, parking, and design criteria). The path and paperwork differ by ADU type.
Looking for builders familiar with your city's checklist? Get matched with teams who pull ADU permits every week.
Note: Short-term rentals, owner-occupancy, parking, and utility rules are local. HOA rules may be stricter than city code. Always verify current requirements before design.
Estimate Your ADU in Minutes
Use the Utah-specific ADU Cost Calculator to ballpark your budget based on size, type, finishes, and utility distance. It's free, fast, and helps you compare quotes on equal footing.
Estimates are not a bid. Final pricing depends on plans, site conditions, inspections, and current material & labor markets.
Why Utah ADU Hub
Utah expertise
Builders fluent in Wasatch Front zoning, snow loads, and energy codes.
Permit-savvy design
Vetted builders front-load feasibility so plans clear review faster.
Transparent bids
One scope, multiple prices—no apples-to-oranges.
Rental-ready options
Sound control, separate utilities, and egress done right.
Financing-friendly
Builders comfortable with lender inspections and draws.
Common Utah ADU Mistakes (and How to Avoid Them)
Skipping a zoning check
Verify setbacks, height, lot coverage, and parking before design.
Underestimating utilities
Sewer depth, water sizing, gas load, and electrical service upgrades can swing budgets.
Poor sound isolation
Basements need STC/IIC strategies for comfort and code.
No separate fire/life-safety plan
Egress windows, fire separation, and smoke/CO alarms are non-negotiable.
Weak scope definition
Ambiguity = change orders. Lock the spec before bidding.
DIY permit run
Small submittal errors create big delays. Use permit-proven teams.
Service Area
Utah ADU Hub matches homeowners with ADU builders across the Wasatch Front and beyond: Salt Lake City, West Valley City, West Jordan, Sandy, South Jordan, Provo, Orem, Lehi, American Fork, Draper, Herriman, Riverton, Ogden, Layton, Bountiful, and nearby communities.