ADU Builders in Provo & Utah County: Costs, Local Rules, and How to Get Started

Last reviewed: June 27, 2026 · Sources: Utah Code §10-21-303 — Internal ADUs; §10-21-304 — Detached ADUs (SB 284, effective Oct 1, 2026); Provo City Code & Development Services. Local rules can change after state legislation or city ordinance updates. Always verify final eligibility with the city before purchasing plans, ordering prefab units, or applying for financing.

Building an ADU in Provo or Utah County typically costs $150,000–$350,000 for a detached unit, or roughly $150–$350 per square foot. Basement conversions can start closer to $40,000. Both Provo and Orem allow accessory dwelling units on residential lots, but the rules differ by city — and getting the zoning wrong before you hire a builder is the most expensive mistake you can make. This guide covers exact costs, city-by-city regulations, the full permitting timeline, how to vet contractors, and what kind of rental income you can realistically expect in Utah County.

Written by Utah ADU Builders, ADU Project Advisors · Last updated: June 27, 2026 · Sources: Provo City Code, City of Orem, Utah Legislature (§10-21-303, formerly §10-9a-530), Utah DOPL, Angi, HUD Fair Market Rents

Provo vs. Orem vs. Other Utah County Cities — Rules at a Glance

This is where most people get stuck. Every Utah County city has its own version of the rules, and digging through municipal code isn't most people's idea of a good time.

We compiled the key details. Here's what you need to know.

Provo ADU Rules (Detailed)

Provo's ADU regulations are found in Provo City Code §14.30.030, and they're more detailed than most cities in the county. Here are the key requirements, cited directly from the city's published rules:

Provo contacts:
Development Services (zoning questions): 801-852-6427
Building Division: provo.gov/200/Building

Orem ADU Rules

Orem calls them "accessory apartments" rather than ADUs, but the concept is the same. Key differences from Provo:

UVU factor: Orem is home to Utah Valley University (40,000+ students), creating strong rental demand similar to Provo's BYU market.

Orem contacts:
General: 801-229-7000
Official checklist: orem.gov/accessory-apartments/

Other Utah County Cities — Quick Reference

Utah state law requires all municipalities to allow internal ADUs in residential zones. Detached ADU rules vary by city. Here's a quick reference for the rest of Utah County:

Important: "Check city" doesn't mean "probably no." It means the detached ADU rules are set locally, and you need to call to confirm. Many of these cities do allow detached ADUs — but the size limits, setbacks, and requirements vary. Always call before assuming.

What Utah State Law Says (The Baseline for Every City)

Regardless of which city you're in, Utah Code §10-21-303 (formerly §10-9a-530) establishes these statewide rules:

• Internal ADUs are a permitted use in areas zoned primarily for residential use.
• The owner must occupy the property as their primary residence.
• Rentals must be long-term (30+ consecutive days) for internal ADUs.
• Internal ADUs are not subject to impact fees — that's a real cost savings.
• HOAs cannot block internal ADUs that would otherwise be permitted by local zoning. This is a big deal. If your HOA tells you no, state law says otherwise for internal units.
• Cities can require: maintaining single-family appearance, one additional parking space (with some exceptions), no separate utility meter (for internal), and recording a notice with the county recorder.

Sources: Utah Code §10-21-303 (formerly §10-9a-530) (le.utah.gov); Utah Property Rights Office (propertyrights.utah.gov)

Garage Conversion ADU: The Budget-Friendly Path

Garage conversions are the most searched ADU cost question in the Provo area — and for good reason. If you already have a garage you're not fully using, converting it is usually the most affordable way to add a living unit to your property.

What Makes Garage Conversions Cheaper (and What Doesn't)

The savings come from having a structure already standing: walls, roof, and foundation are already there. What you're paying for is turning an unfinished shell into a livable space.

What you can usually reuse:

• Existing slab foundation (if in good condition and level)
• Roof structure (if it meets code for occupied space)
• Exterior walls (with added insulation)

What you'll almost certainly need to add or upgrade:

• Insulation (walls, ceiling, and potentially under the slab)
• Plumbing for kitchen and bathroom
• Electrical panel upgrade or subpanel
• HVAC (mini-split systems are the most common choice for ADU conversions)
• Egress windows or doors (required for bedrooms)
• Fire separation between ADU and main dwelling (if attached garage)
• Drywall, flooring, and interior finishes
• A separate entrance (Provo requires new entrances to be on the side or rear)

What Drives Garage Conversion Costs Up Fastest

If you want to control your budget, focus on these high-impact decisions:

1. Moving plumbing — Adding a bathroom where no plumbing exists is the single most expensive variable. If you can locate the bathroom near an existing sewer line, you'll save thousands.
2. Electrical service upgrade — If your home's electrical panel can't support the additional load, a panel upgrade runs $1,500–$4,000.
3. Foundation work — If the garage slab is cracked, sloped, or not rated for living space, you may need remediation or even replacement. This can turn a budget project into an expensive one fast.
4. Ceiling height — Many garages have low ceilings. If yours doesn't meet code height for habitable space (typically 7 feet minimum), you have a problem that's expensive to solve.

Garage Conversion Readiness Checklist

Before you commit to the garage conversion path, check these items. If you fail on the bolded ones, a garage conversion may not be your cheapest option after all:

• ☐ Slab is level, uncracked, and in good structural condition
• ☐ Ceiling height meets or exceeds 7 feet
• ☐ Existing sewer line is within reasonable distance (under 50 feet)
• ☐ Electrical panel has capacity or space for a subpanel
• ☐ Roof is in good condition and doesn't need replacement
• ☐ Walls are plumb and structurally sound
• ☐ No evidence of water intrusion or moisture problems
• ☐ Property has enough parking even without the garage (remember Provo's 4-space requirement)
• ☐ Garage is not in a flood zone or drainage path
• ☐ Access for a separate entrance exists on the side or rear

How to Choose the Right ADU Builder in Utah County

This is where most homeowners feel the most anxiety, and for good reason. An ADU is a $100,000+ investment, and the contractor you choose determines whether the project comes in on time, on budget, and built to last — or becomes a horror story.

Here's how to do it right.

The ADU Builder Scoring System

When you're comparing bids, don't just look at the bottom-line price. Use a structured evaluation. Here's a scoring framework you can adapt:

The 12 Questions to Ask Every ADU Builder

Before you sign with anyone, ask these:

1. "How many ADUs have you built in [my city]? Can I see them or talk to the owners?"
2. "Who pulls the permits — you or me?"
3. "What's your realistic timeline, and what could delay it?"
4. "What's included in your bid and what's excluded?"
5. "What are the allowances in your bid? What happens when I pick materials that cost more?"
6. "How do you handle change orders? What's the markup?"
7. "What's your payment schedule? What triggers each payment?"
8. "What's your warranty on workmanship?"
9. "Who are your subcontractors for plumbing, electrical, and HVAC? Are they licensed?"
10. "What happens if you go over budget or over schedule?"
11. "Do you carry general liability insurance and workers' compensation?"
12. "Can you provide your Utah contractor license number right now?"

A good contractor will answer all of these without hesitation. A bad one will get evasive or annoyed.

Red Flags — Walk Away If You See These

• No verifiable Utah contractor license. This is non-negotiable.
• Demands a large payment upfront (more than 10% before any work starts).
• "We don't really need permits for this." Yes, you do. Always.
• Cannot show you a single completed ADU project.
• Vague scope of work — if the bid is one page with a lump sum, you'll be arguing about what's "included" for the next six months.
• No written change order process. Change orders are where budgets explode. If there's no written process, you're vulnerable.
• The bid is dramatically lower than others. The cheapest bid usually means something is missing from the scope, or the contractor is planning to make it up in change orders.

How to Compare Three Bids (Apples to Apples)

When you get three bids, they'll probably look different — different line items, different categories, different levels of detail. Here's how to compare them fairly:

1. Create a master list of every line item from all three bids combined.
2. Fill in the gaps — if Contractor A includes landscaping but Contractor B doesn't, note that.
3. Compare allowances — if one bid has a $5,000 kitchen allowance and another has $15,000, those aren't comparable without knowing what each gets you.
4. Add back anything that's "excluded" to get the real total.
5. Weight the non-price factors from the scoring table above.

The goal isn't finding the cheapest bid. It's finding the best value from a contractor you trust who can actually deliver.

ADU Rental Income and ROI in Utah County

Let's talk about whether the numbers actually work. Because an ADU is an investment, and investments need to pencil out.

What Can You Charge for an ADU Rental in Provo and Orem?

Rental rates in Utah County depend on size, location, condition, and proximity to BYU or UVU. Here's what the data shows:

Sources: HUD Fair Market Rents for Provo-Orem MSA (ushousingdata.com); Apartments.com Utah rent trends; Zillow Rental Manager

The BYU and UVU Rental Advantage

Utah County has something most ADU markets don't: two major universities creating year-round rental demand.

BYU enrolls over 30,000 students, and UVU enrolls over 40,000. That's 70,000+ students who need housing, and neither university can house all of them on campus. Off-campus student housing in Provo typically runs $400–$1,200 per person per month, depending on the arrangement.

This means:

• Demand is consistent. It's not seasonal like tourist markets.
• Vacancies are low. Student housing near campus rarely sits empty for long.
• Tenant turnover is predictable. Leases align with academic semesters.
• Provo's 30-day minimum rental requirement aligns perfectly with semester-length leases.

An ADU within walking or biking distance of either campus is a particularly strong rental asset.

A Simple ROI Framework

Here's how to think about the financial return. This is simplified — your actual numbers will depend on your specific costs, rent, financing, and tax situation.

Example: Detached 1-bed ADU, $200,000 total cost

• Cash-on-cash return (if paid cash): ~5.5%
• Simple payback period: ~18 years
• But that's not the whole story. Property value increase from an ADU is estimated at 20–35% of the ADU's construction cost. On a $200,000 ADU, that's $40,000–$70,000 in added home value — equity you gain immediately.

The real math: When you factor in property appreciation, rental income, tax benefits (depreciation, mortgage interest deduction if financed), and the long-term value of having a flexible space, most Utah County ADU investments pay for themselves well within the mortgage period.

Disclaimer: This is an illustration, not financial advice. Actual returns depend on your specific situation. Consult a financial advisor or CPA for investment decisions.

Beyond Rental Income — Other Ways ADUs Create Value

Not every ADU is about monthly rent checks:

• Multi-generational housing: Keep aging parents nearby without giving up anyone's independence.
• Boomerang kids: Adult children returning home get their own space (and everyone stays sane).
• Home office or studio: Separate workspace on your property — no commute, potential tax deductions.
• Future downsizing: Move into the ADU and rent the main house, or vice versa.
• Property value floor: Even if you never rent it, the ADU adds appraisal value.

Permits and Inspections — What to Expect

Nobody loves the permitting process, but understanding it prevents surprises.

What You'll Need for Your Permit Application

Most Utah County cities require:

• Completed application form from the city's Building Department
• Site plan showing ADU location, setbacks, parking, and utility connections
• Architectural plans (floor plans, elevations, cross-sections)
• Structural engineering stamped by a licensed Utah engineer
• Energy compliance documentation
• Utility confirmation (water and sewer availability)
• Application fees (vary by city — Orem's checklist shows a range of approximately $100–$1,000)

Provo-Specific Permit Notes

From Provo's published requirements:

• Building permit is required before any work begins
• An interior inspection verifies code compliance
• The city will issue corrections if needed — you fix them, then pass final inspection
• The deed restriction (ADU Agreement) must be notarized and recorded with Utah County Recorder
• The rental dwelling license is a separate application once the ADU passes final inspection

How to Avoid Permit Rejections

The most common reasons permits get kicked back:

1. Plans don't show required setbacks clearly. Double-check your measurements.
2. Missing engineering. Structural, and sometimes civil engineering, is typically required.
3. Incomplete utility plans. Show where water, sewer, electric, and gas connect.
4. Parking doesn't meet the code. In Provo, four spaces are required.
5. Energy code non-compliance. Utah has adopted energy code requirements — your designer needs to address them.

A good architect or designer who's worked in your city before will know what the Building Department wants to see and can save you rounds of revisions.

Common Mistakes That Blow Budgets and Timelines

We've seen these patterns over and over. Every one of them is avoidable.

Why Build an ADU in Utah County Right Now?

If you've made it this far, you're serious. Here's the context that makes this a particularly good time to act:

Utah's population growth is among the fastest in the nation. The state is projected to grow from 3.6 million to 5.6 million by 2065, according to the Kem C. Gardner Policy Institute. That means sustained housing demand for decades.

The legislature is actively encouraging ADUs. Utah has passed increasingly favorable ADU legislation, requiring cities to allow internal ADUs and limiting the ability of HOAs to block them. The regulatory environment is moving in your favor, not against you.

University-driven rental demand isn't going away. BYU and UVU aren't shrinking. Between them, 70,000+ students need housing every year. An ADU near either campus is as close to a guaranteed tenant base as residential real estate gets.

Interest rates and construction costs will fluctuate, but property values in Utah County have a strong long-term trajectory. Building an ADU now means locking in today's construction costs while benefiting from future appreciation.

Provo's own General Plan identifies ADUs as a strategy for increasing housing supply. The city recognizes the need and has signaled support at the planning level.