Utah ADU Builder
Pricing
Cost of an ADU in Utah
Ballpark ranges for planning conversations — not a bid. Numbers below reflect typical Wasatch Front build costs we use in the on-site estimator (finish level and site conditions move them).
| ADU type | Typical band | What usually drives it |
|---|---|---|
| Internal suite / granny flat inside the house | $55,000–$145,000 | Finish level, existing structure, egress |
| Garage conversion | $70,000–$175,000 | Openings, insulation, replacement parking |
| Detached casita or granny flat | $95,000–$250,000+ | Size, utilities, hillside, sprinklers |
Last reviewed 2026-09-22. Soft costs often add about 8% or more.
Start with a planning band, not a Google average
National ADU headlines rarely match Utah snow load, impact fees, or Wasatch Front labor. Use the bands below to frame HELOC conversations, then tighten with the interactive estimator.
Soft costs (permits, design, engineering) commonly add on the order of ~8% in our estimator model — cities and soils reports can push higher.
Internal suite
$55–145k
Mid finish, typical site
Garage path
$70–175k
Openings + parking tradeoffs
New detached
$95–250k+
Size & utilities drive high end
Soft costs
~8%+
Permits · design · engineering
Assumption · Illustrative mid-finish Wasatch Front bands used in our public estimator — not a quote. Unusual soils, hillside retaining, or sprinklers move projects outside these envelopes.
Where a detached dollar often goes
100%
Illustrative mix
- Structure & envelope34%~34%
- MEP systems22%~22%
- Finishes & kitchen/bath20%~20%
- Site / utilities14%~14%
- Soft costs & contingency10%~10%
Assumption · Educational split for a mid-complexity backyard unit. Internal conversions usually shrink the site/utilities slice and raise finishes share.
What usually moves the number
| Factor | Low impact | High impact |
|---|---|---|
| Finish tier | Simple fixtures | Custom kitchen/bath |
| Utilities | Short stub | Long trench / capacity upsize |
| Site | Flat, open rear yard | Hillside / retaining / snow |
| City process | Clear ADU path | Overlays + impact fees |
Assumption · Use as a risk checklist when reading an early estimate.
Tune a band for your square footage
Assumption · Calculator uses the same illustrative $/sf coefficients as other topic tools on this site. It is a planning aid, not a contractor bid.
Get a property-specific range
Map the address, run the estimator, then start a project with that scope attached.
Questions people ask about Utah ADU cost
How much does it cost to build a casita in Utah?
A new detached casita on the Wasatch Front often plans in the $95,000–$250,000+ band before unusual site work. An internal suite is often about $55,000–$145,000, and a garage path about $70,000–$175,000. These are planning bands, not a bid.
What is included in a Utah ADU cost band?
The bands describe typical construction for a mid finish. Soft costs such as design, engineering, and permits often add about 8% or more. Hillside retaining, long utility runs, and sprinklers move a project outside the band.
Does a granny flat cost the same as a casita?
The legal product is an ADU either way. An internal granny flat usually lands in the lower band. A detached granny flat or casita usually lands in the detached band.