ADU permit timeline in Utah County: from permit to move-in

Plan on roughly four to six months from kickoff to move-in for an ADU in Utah County. That window covers architecture, city permitting, and construction. Design and a complete submittal come first, then the city's review, which runs on the city's clock. Construction and inspections follow, and you get keys after the certificate of occupancy. Revision rounds and utility connection scheduling are what usually stretch the schedule.

The phases, in the order they actually happen

Every backyard unit we build in Utah County moves through the same sequence, whether it lands in Lehi, American Fork, Pleasant Grove or an unincorporated pocket. First comes design: a site plan showing where the unit sits, floor plans, elevations, and the structural and mechanical details a plan reviewer needs. Then the permit application goes in. The city reviews it, usually across several departments — building, planning, engineering, sometimes fire and the water department. Comments come back, drawings get revised, and the permit issues.

From there the work is physical. Excavation and foundation, utility trenching and connections, framing, rough-in inspections for plumbing, electrical and mechanical, insulation, drywall, finishes, and a final inspection. When the city signs the final, it issues a certificate of occupancy, and that piece of paper is what legally turns the building into a home someone can live in.

The full sequence — architecture, permitting, construction — typically runs about four to six months on a straightforward lot. That number is not a promise, because two of those phases depend on parties outside our control: the city and the utility providers.

Design and pre-application: where you save the most time

The cheapest weeks to save are the ones before you ever submit. That means confirming what your zone allows, how big the unit can be, where the setbacks land, and whether the city wants an extra parking stall before anyone draws a floor plan you love. Rules differ street by street, which is why it is worth reading up on how ADU rules work city by city in Utah County early rather than after drawings exist.

This is also when we walk the property. Where does the sewer lateral run, and how deep? Can a concrete truck and an excavator get to the build area, or does everything come through a four-foot gate? Is there an irrigation ditch, an easement, or a big tree in the way? Those answers shape both the drawings and the budget, and they are the same factors that drive what an ADU actually costs to build in Utah.

Financing belongs in this phase too. Draw schedules and lender inspections take time to set up, and it is much easier to line those up while drawings are being finished than to pause a permitted project waiting on funding.

Permit submittal and city review: the part you do not control

Once the application is in, the clock belongs to the city. Review windows vary by jurisdiction and by season — spring and early summer submittals tend to sit in a longer queue than a set of drawings dropped in November. Some Utah County cities review a small residential ADU quickly; others route it through more departments. Nobody outside the counter can tell you exactly how long yours will take, and no builder can tell you what a city will approve.

What you can control is how many rounds it takes. A complete, coordinated submittal — site plan matching the structural drawings, utility plan matching the site plan, energy code documents included, fees paid — often clears in one or two rounds of comments. An incomplete one restarts the wait every time it goes back. That is the single biggest swing factor in the ADU permit timeline in Utah County: not the city's speed, but how many times you go around with them.

Plan for at least one round of comments. It is normal. Reviewers ask questions, we answer them, drawings get stamped, and the permit issues.

Construction, inspections, and getting the keys

Construction on a site-built ADU is handled by our local Utah crew, and it follows a rhythm set by inspections. You cannot cover a wall until rough-in passes. You cannot pour until the footing inspection clears. Scheduling those inspections is generally quick along the Wasatch Front, but a failed inspection costs days, not hours, because it means correcting work and getting back on the schedule.

Utility connections are the other common holdup. Water and sewer taps, a power meter set, and gas service each depend on someone else's calendar. We schedule those as early as the permit allows, because a finished home waiting on a meter is the most frustrating kind of delay there is. Winter matters too — concrete and excavation in a Utah January need extra measures, and weather can push a week here or there.

After the final inspection and the certificate of occupancy, the unit is legally habitable. If you plan to rent it, that document is also what makes the unit a permitted rental in the eyes of your city and, later, an appraiser — which matters if you are counting on rental income from an ADU in Utah to offset the loan.

What compresses the schedule and what stretches it

Things that pull the timeline in: a flat lot with good access, a short utility run, a complete first submittal, a floor plan you are not still redesigning, financing already in place, and a decision made early on finishes so nothing is on backorder at the end.

Things that push it out: revision rounds, a lot on a slope or with unknown soil, a long sewer trench or a required pump, HOA review layered on top of city review, panel upgrades that need utility coordination, and changes made after the permit is issued. A mid-build change is not just the cost of the change — it can mean a revised drawing going back to the same reviewer.

One more option worth knowing about: a tiny home built in our Lehi shop skips most of the site-work risk, because the home is under construction indoors while the pad and utility stubs are being prepared. The permitting path is different, and it is not right for every property, but it can be a shorter route to someone actually living on your land.

Frequently asked questions

How long does it take to get an ADU permit in Utah County?

It depends on your city and how complete your submittal is. Each city sets its own review window, and there is no single county-wide answer. A coordinated set of drawings often clears in one or two rounds of comments; an incomplete set restarts the wait each time. Budget for review as a real phase in your schedule, not a formality, and submit in a slower season if you have the flexibility.

What is the total time from first meeting to move-in?

About four to six months is typical for a straightforward Utah County lot, covering architecture, city permitting, and construction. Lots with steep grade, poor access, long utility runs, or extra review layers like an HOA run longer. Design changes made after the permit is issued are the most common self-inflicted delay.

Can I start building while the permit is under review?

No. Work that requires a permit has to wait until the permit is issued, and building early risks correction notices and rework. What you can do during review is finalize finish selections, confirm financing and draw schedules, clear the build area of sheds or landscaping, and line up utility coordination so those calls are already in motion the day the permit lands.

What is a certificate of occupancy and when do I get it?

It is the document the city issues after the final inspection passes, confirming the unit is legally habitable. You get it at the very end, after all rough-in and final inspections clear and utilities are connected and live. Until it is issued, nobody should move in — and if you plan to rent, it is the paperwork that makes the unit a permitted dwelling.

Does a tiny home on wheels take less time than a site-built ADU?

Often, yes, because the home is built in our Lehi shop while site prep happens in parallel, and there is far less excavation risk. The approval path is different — cities treat a movable unit differently than a permanent ADU, and the city decides what is allowed on your parcel. It is worth comparing both before you commit to one.

If you are weighing an ADU or a tiny home for your property, come walk the model homes in Lehi and we will talk through what your lot and your city would likely require. See our homes at mycocoonhomes.com.