Detached ADUs & Backyard Cottages in Lehi, UT

Why Lehi homes are good candidates for detached ADUs

Lehi has grown faster than almost anywhere in the country, and the growth pattern created a very specific opportunity. Thousands of homes were sold in the last fifteen years with unfinished basements, bought by tech-corridor families who have since outgrown the main floor. Finishing the basement is nearly always cheaper per square foot than moving — and in this market, moving means competing for inventory that barely exists.

The housing stock here is an extraordinary range — historic homes near downtown alongside enormous 2005-and-newer subdivisions in Traverse Mountain, Holbrook Farms, and the Thanksgiving Point corridor. That shapes what a project actually involves — which is why we scope work in Lehi differently than we would two cities over.

Neighborhoods we work in

We take detached ADUs projects throughout Lehi, including Traverse Mountain, Thanksgiving Point, Holbrook Farms, Spring Creek, Dry Creek, Jordan Willows, and Historic Downtown Lehi. Landmarks nearby include Thanksgiving Point, Silicon Slopes tech corridor, Traverse Mountain Outlets.

What Lehi allows

Lehi has already done this. The city approved its implementing ordinance in July 2026, and the change is large: the detached lot minimum was 14,520 square feet and is now the state's 11,000. A detached unit needs a six-foot setback, has to be smaller than the main house, and has a 300 square foot floor. Parking is two stalls for a unit of 650 square feet or more, one below that. The city's own estimate was that eligible properties would increase by more than 20% — so if you were told no in Lehi before, ask again.

Checked against Lehi City — ADU development code amendment (Chapter 26) and Utah County cities prepare for statewide detached ADU changes — Daily Herald on 2026-08-31. Rules differ city by city and the detached ones are being rewritten ahead of an October 1, 2026 deadline — see where all nine cities stand, or let us confirm your specific parcel.

What's included

• Lot, zoning, and setback feasibility check before any design work
• Site plan and unit design, with our designer
• Foundation, framing, roofing, siding, and windows
• Complete kitchen and bathroom
• Utility connections — water, sewer, power, and gas where applicable
• Separate electrical service or subpanel, with submetering where you want it
• Full permitted construction through certificate of occupancy
• Site restoration, grading, and drainage away from both structures

Permits and inspections in Lehi

Lehi's building department handles significant permit volume given the city's growth, so scheduling inspections with some lead time keeps projects moving. Newer Traverse Mountain and Holbrook Farms homes typically have rough plumbing stubbed and egress windows installed, which simplifies both cost and permitting.

Permits here go through the Lehi City Building Department. Lehi processes a large volume of permits — it's one of the fastest-growing cities in the state — so plan review and inspection slots are worth booking with lead time rather than assuming next-day availability. We build that into the schedule up front instead of letting it become a mid-project delay.

Because of Lehi's construction volume, we schedule inspections several days out rather than the day before. The practical effect is that a project moves at a predictable pace instead of stalling between stages waiting for an opening.

Newer Lehi homes — Traverse Mountain, Holbrook Farms, and most of the recent construction on the north and west sides — were typically built with rough plumbing already stubbed for a future bathroom and egress windows already installed. That can take a meaningful amount off both the cost and the permit complexity compared with cutting an egress opening into an older foundation. It's the first thing we check on a walkthrough, because it changes the estimate substantially.

We handle this part; it isn't something you deal with.

For the full walkthrough of how a project runs stage by stage, what drives the price, and what to watch out for, see our detached ADUs page.

Lehi permit details above were checked against the city's published information on August 19, 2026. Cities revise fees and ordinances, so confirm current requirements with Lehi City — ADU development code amendment (Chapter 26) and Utah Code 10-9a-530 — internal accessory dwelling units — or let us confirm it for your address as part of the estimate.