A 1,200 sq ft cap
Most of our plans for detached use come in well under 1,200 square feet.
Alpine, Utah County
Alpine has adopted detached ADU rules.
The Alpine City Council adopted its detached ADU ordinance in early September 2026 to meet SB 284. If you own a larger Alpine lot, a separate home in the backyard may now be possible, within the city's size cap.
Adopted September 2026
What we confirmed for Alpine
Source: Alpine City Council and Planning Commission coverage, September 2026; Deseret News, October 14, 2026; Utah Code 10-21-304.
- Adopted
- September 2026, after extended council debate
- Size
- Maximum ADU size of 1,200 sq ft, as reported
- Registration
- Annual ADU registration was recommended by the Planning Commission
- Next step
- The council said it will revisit lot-coverage rules within six months
- State floor
- Lots of 11,000 sq ft or more with a single-family home must qualify
- Parking
- State law caps it at 1 space under 650 sq ft and 2 at 650 sq ft or more
Not confirmed: The ordinance number and vote count, plus final setbacks, parking and lot-coverage rules. Confirm with Alpine City.
About Alpine
Lone Peak above, big lots below, and a rule still being tuned.
Alpine sits at the northeast corner of Utah County at the foot of Lone Peak, with Highland and Lehi to the west and the mouth of American Fork Canyon nearby. It is a city of large lots, mountain views and long driveways, and the quarter-acre threshold in state law is easy to clear for many properties.
Alpine's council debated at length and adopted a rule with a 1,200 square foot size cap. It also promised to revisit lot coverage within six months, so expect the lot-coverage rules, which control how much of your yard a new building can take, to change. Anyone building here should plan for the rule as it stands and ask the city before signing.
What it means for you
What this means for a Alpine homeowner.
Lot coverage is next
The council committed to revisit lot coverage within six months, so ask for the latest text before you design.
Registration
The planning commission recommended annual ADU registration, a small recurring step to plan for.
Larger lots
Many Alpine lots are well above the 11,000 sq ft state threshold, which leaves room to place a unit thoughtfully.
Plans that fit Alpine
The biggest plans that still fit a 1,200 sq ft cap.
Alpine's size cap leaves room for the larger ADU plans. Morada 1000 and Eagle Landing 1000 are single-level homes near 1,000 square feet, Rabbit 1000 is a two-story, two-bedroom plan, and Torrey Flats is 696 square feet. All sit under 1,200 square feet. Anything over 650 square feet needs two parking spaces.
Final fit depends on your lot, utilities, the delivery route and Alpine's current standards. We confirm all of it in a lot review.
Long runs and mountain-side access.
Big lots mean long sewer, water and power runs, and mountain-side lots can have slope, rock and tight access roads. The delivery truck and crane have to reach the site. We check access, slope and utility distance in a lot review and price the site work before you pick a plan.
How to plan the full budgetGetting it built in Alpine
From a Alpine lot to move-in.
- Confirm lot size and coverage. Ask Alpine for the current lot-coverage rules.
- Plan the placement. Choose a spot with access for the truck and crane.
- Choose a plan. Stay under 1,200 square feet.
- Alpine review. We prepare the plan set and site plan for city review and the building permit.
- Site work, set and finish. Foundation and utilities, crane day, then finish work.
Questions
Alpine ADU questions, answered.
Has Alpine adopted detached ADU rules?
Yes. The City Council adopted a detached ADU ordinance in early September 2026, after extended debate, according to local coverage. The ordinance number and vote count are unconfirmed.
What is the maximum size in Alpine?
The council reportedly set a maximum ADU size of 1,200 square feet.
Will Alpine change the rules again?
The council committed to revisit lot-coverage rules within six months, so check for updates before you build.
Does Alpine require registration?
The Planning Commission recommended annual ADU registration. Confirm the adopted requirement with the city.
What lot size do I need in Alpine?
State law sets 11,000 square feet as the largest minimum a city can require. Confirm Alpine's final wording with the city.
General information, not legal advice. Cities can amend their ordinances, so confirm current rules with Alpine before you design or buy.
Nearby
Compare nearby cities.
Neighbors at the north end of Utah Valley:
Own a lot in Alpine?
Send us your address. We will check access, slope and the current rules, then tell you honestly whether a detached ADU fits.