ADU builder in Utah County, Utah

ADU rules by city in Utah County

Last reviewed October 6, 2026 · Every city's full rules on our Utah ADU tracker

Where ADU rules are most flexible in Utah County

• Smallest stated lot minimum: Spanish Fork, at 10,000 sq ft, below the state's 11,000.
• No lot minimum on our tracker: Cedar Hills, Pleasant Grove, Springville and Payson don't list one. Alpine allows ADUs wherever single-family homes are permitted and sizes them in tiers by lot; Eagle Mountain's minimum depends on the zone.
• Owner may live in either unit: Lehi, Alpine and Eagle Mountain, plus Santaquin's draft. Cedar Hills requires registration and lets one unit be rented.
• Longest track record: Springville has allowed ADUs since 2020 and Payson since November 2024.
• No SB284 ordinance yet, so the state rule applies: Provo, Vineyard and Santaquin. Provo still allows ADUs under its existing code.
• Newest: Orem and American Fork both adopted on September 22, 2026, the first time either city has allowed detached ADUs.

What a backyard ADU costs across Utah County

Across Utah County, a finished Cocoon ADU usually costs $85,000–$200,000 all-in. The home itself starts at about $63,000 for the 170 sq ft 100 Series studio and runs to about $109,000 for the 500 sq ft two-bedroom 500 Series. On top of that, site work, utilities and city costs add 35–50%, mostly set by how far your sewer, water and power have to run; city fees on their own typically run $3,500–$9,000. Our best-selling 300 Series one-bedroom comes in around $113,000–$126,000 all-in, against $200,000–$400,000 or more for a traditional custom-built ADU. The full breakdown: Utah ADU costs.

What Utah County ADUs rent for

We have city-level figures for two Utah County cities: a one-bedroom rents for about $1,379 a month in Lehi and about $1,299 in Provo. Elsewhere in the county we use the Wasatch Front regional range of $1,200–$2,500 a month, with a typical one-bedroom at $1,200–$1,500; that's a regional range, not a city figure. At $1,300 a month, a $113,000 build pays back in about 7–7.5 years of gross rent. Most Utah County cities on our tracker require the owner to live on the property, so plan on renting one unit, not both. More on the math: ADU rental income in Utah.

How a Utah County ADU build works

1. We match your lot to its city's rules. Each of the 18 cities sets its own lot, setback and parking rules, or follows the state rule, so the first step is reading your address against the right one.
2. You choose a plan and finishes. Start from one of our five floor plans or a custom footprint sized to your city's limits.
3. We submit engineer-stamped plans. We prepare the permit set and submit it to your city for you.
4. Our crew builds on site. Our own Utah crew builds your ADU on a permanent foundation on your lot.
5. Inspection, utilities, keys. We close out the city's final inspection, connect utilities and hand over the keys.

Utah County builder pages: Lehi · Provo

More on Utah ADUs: Utah ADU homes · ADU rules in 34 Utah cities · Floor plans