White City ADU Builders: Rules, Costs, and Whether Your Lot Qualifies
Searching for White City ADU builders? Here, the smartest first move isn't a quote — it's confirming what your lot allows. The clearest path is an internal ADU (a second unit inside your existing home, like a basement apartment): Utah law makes these permitted, and White City allows them with conditions. Detached backyard units become newly possible under a state law effective October 1, 2026. Plan on roughly $50,000–$400,000+, and every ADU needs a permit.
Best for owner-occupants housing family or renting long-term. Not for investors who want to rent both units or run a short-term rental.
Last verified: June 2026. Utah ADU law and White City's ordinance are changing right now, so treat every rule here as "confirm for your parcel before you build."
About this guide: Utah ADU Builders is an independent Utah ADU planning, feasibility, and builder-matching resource. We are not White City, the Municipal Services District, Salt Lake County, a law firm, lender, architect, engineer, or licensed contractor. We may earn compensation when homeowners request an estimate or are connected with local professionals — but that never changes how we explain the rules, costs, or risks below.
The short version, before you scroll
| Your question | The honest answer for White City |
|---|---|
| Should I call a builder first? | Usually no. Start with feasibility so any estimate is based on your ADU type, lot, parking, utilities, and the current rules — not on a project that can't be permitted. |
| Are internal ADUs (basement apartments) allowed? | Yes. Utah law protects internal ADUs, and White City allows them in certain residential zones — with conditions (White City resident notice, June 2025). |
| Are detached backyard ADUs allowed? | Treat this as in transition. As of White City's June 2025 notice they weren't allowed, but Utah's detached-ADU law takes effect October 1, 2026 and White City is expected to update its rules. Confirm the current White City ordinance before planning one. |
| Do I need a permit? | Yes — always. An ADU is a permitted construction and licensing project, not an informal remodel. |
| Can I rent it on Airbnb? | Not as an internal ADU. White City internal ADUs are long-term housing (stays of 30 days or more). Detached-ADU rental rules will follow White City's forthcoming ordinance — confirm before relying on any rental plan. |
| Do I have to live on the property? | Yes, for an internal ADU. Owner occupancy is required. |
| What will it cost? | Plan on a wide range — roughly $50,000 for a simple basement conversion up to $400,000+ for a detached build. These are estimates that move with your site and finishes. |
| Best next step | A property-specific feasibility check before you compare builders or request quotes. |
What we verified (and where it came from)
We built this page from primary and official sources, not guesswork or generic national ADU pages:
- Utah state ADU law — internal-ADU rules and the impact-fee exemption (Utah Code §11-36a-202), plus Utah's detached-ADU law (Senate Bill 284; Utah Code §10-21-304, effective October 1, 2026), via the Utah Legislature and the Utah Property Rights Ombudsman.
- White City's own ADU rules — White City's official June 2025 resident notice on internal ADUs and short-term rentals.
- Who permits White City — White City's status as a city of the fifth class and its use of the Greater Salt Lake Municipal Services District (MSD) for planning and permitting.
- Cost inputs — our own Utah ADU project data plus current Utah contractor ranges, presented as estimates.
Full source links are at the bottom of this page.
Should you call White City ADU builders — or check feasibility first?
Check feasibility first. A builder can price whatever you ask for, but a White City ADU can be reshaped or blocked by ADU type, owner occupancy, parking, rental rules, utility capacity, lot size, and the permit process. Knowing which path is realistic before you request a quote saves you money and disappointment.
Here's the plain truth: an ADU is not automatically a smart project just because Utah has become more ADU-friendly. The right project depends on your lot, your existing home, your city's current rules, your utilities, your budget, and what you actually need the unit for. A basement apartment for a parent, a garage conversion for rental income, and a detached backyard cottage look similar on a quote request but trigger completely different rules and costs. Feasibility is what turns a vague idea into a specific, permittable project.
Who approves ADU permits in White City?
White City is a city, but it does not run its own building department. It became a city of the fifth class in 2024, and it contracts with the Greater Salt Lake Municipal Services District (MSD) for planning, zoning, and building permits. So your ADU is reviewed under White City's ordinance and administered through the MSD.
Two things this means in practice:
- →You do not apply to Sandy. White City sits surrounded by Sandy and shares its "feel," but it is a separate jurisdiction. Sandy's ADU rules do not govern a White City parcel.
- →"Call your city" is not the finish line. A lot of ADU pages tell homeowners to phone city hall as step one. In White City, planning is handled through the MSD, and the rules differ from a typical incorporated city's. That's exactly why a feasibility check that already knows how White City works is more useful than a phone tag loop.
Are ADUs allowed in White City? Internal vs. detached
Yes — but the answer depends on the type. White City clearly allows internal ADUs with conditions. Detached ADUs are the higher-interest, higher-uncertainty path and should be treated as a rule in transition, because White City's prior position and a new state law that takes effect October 1, 2026 are not the same thing.
Internal ADUs (the established path)
An internal ADU is a self-contained second living unit created inside your existing home — most often a basement apartment, sometimes called a "mother-in-law apartment." White City allows internal ADUs in certain residential zones, and an internal ADU does not turn your home into a duplex or a boarding house.
According to White City's official June 2025 resident notice, an internal ADU is allowed only when it meets the city's conditions, which include (but are not limited to):
| White City internal ADU condition | What it means for you |
|---|---|
| Owner occupancy required | You (the property owner) must live in the home. You can't own it purely as an investment with the main unit rented out too. |
| Occupancy limit | The internal ADU may not house more than four people. |
| Parking | You must provide at least one on-site parking space for the ADU, in addition to the parking required for the main home. |
| Permit + business license | You must obtain a permit for the ADU and a business license, renewed annually for as long as the unit is rented. |
| Long-term only | The ADU may not be rented for stays shorter than 30 consecutive days — no nightly or short-term rental. |
Source: White City resident notice, June 2025 (Internal Accessory Dwelling Units and Short-Term Rentals). White City's online municipal code is provided for convenience; the official code governs, so confirm the current language before you rely on it.
Detached ADUs (a rule in transition — verify before you plan)
A detached ADU is a stand-alone unit in your yard — a backyard cottage or casita, separate from your house. This is the path most in flux in White City:
- As of White City's June 2025 resident notice, the city did not allow the construction and rental of detached ADUs, though a City Council subcommittee was studying the option.
- That's changing at the state level. Utah's Senate Bill 284 enacts a detached-ADU requirement (Utah Code §10-21-304) that takes effect October 1, 2026, requiring certain "specified" cities to allow a detached ADU as a permitted use in some residential zones. The law is built around an 11,000-square-foot lot-size threshold, and cities may also choose to allow detached ADUs on smaller lots.
Do not assume a detached ADU is allowed or off the table in White City without confirming the current ordinance.
Where basement apartments and garage conversions fit
A basement apartment is the most common form of internal ADU and follows the internal-ADU rules above. A garage conversion turns garage space into a living unit; if you convert an attached garage into habitable ADU space, replacing the lost parking can become a real requirement, so factor that in early. Whether a garage conversion is treated as internal or detached — and what's required — depends on your structure and the current rules, so confirm it before committing to a design.
Which ADU type fits a White City home?
The strongest fit for most White City homes is an internal/basement ADU. White City is a mostly mid-century neighborhood of 1950s–60s ramblers, so if your home has a basement or a lower level that could be finished, an internal ADU is usually the lowest-cost, fastest, and (for internal units) impact-fee-exempt path here.
Match the type to your goal:
- →If you want the lowest cost or need to house a parent quickly: an internal/basement ADU usually wins.
- →If you have an underused garage: a garage conversion can be cost-effective — just plan for parking replacement and condition upgrades.
- →If you want maximum privacy or the highest rent and you have the lot for it: a detached unit offers the most separation, but it's the most expensive path and its status in White City is still in transition.
| ADU type | Best for | Main feasibility questions | Biggest cost drivers |
|---|---|---|---|
| Basement / internal | Family housing, long-term rental, lowest disruption | Egress, ceiling height, kitchen, fire/safety, owner occupancy, parking, license | Interior build-out, egress windows, plumbing, electrical, HVAC |
| Garage conversion | Using existing structure, smaller footprint change | Replacement parking, insulation, slab/floor, utilities, livability | Parking replacement, envelope upgrades, plumbing, HVAC |
| Attached addition | More privacy than a basement | Whether White City's current rules allow the specific attached configuration; setbacks, lot coverage, utility tie-ins | Foundation, framing, roofline, utility upgrades |
| Detached / casita | Privacy, aging parents, separate long-term rental | The October 1, 2026 state law, White City's forthcoming ordinance, lot size, setbacks, utilities, parking | Site work, foundation, utility trenching, separate structure |
| Prefab / tiny-home style | Faster design if the site and rules fit | Whether the product meets current White City rules, foundation, access | Unit cost plus foundation, utilities, delivery/set, finish/site work |
In White City today, the internal/basement path is the established option. An "attached addition" is not clearly covered by White City's June 2025 internal-ADU notice, so confirm whether that specific configuration is allowed before designing one. Detached units fall under the October 1, 2026 state law and White City's forthcoming ordinance. A "setback" is the minimum distance a structure must sit from your property lines. Prefab pricing is only part of the total — foundation, utilities, delivery, permits, and site work are real additional costs.
What does an ADU cost in White City?
Costs should be treated as estimates, not quotes, and the biggest variable is project type. A basement conversion that reuses an existing slab, walls, and roof is a completely different budget category than a detached unit that needs its own foundation, utility trenching, and structure.
As a starting framework (Salt Lake Valley estimates, 2026):
| Project type | Typical range (estimate) | Why it moves |
|---|---|---|
| Basement / internal conversion | ~$50,000–$120,000 | Existing plumbing, egress, ceiling height, kitchen, electrical/HVAC |
| Garage conversion | ~$80,000–$150,000 | Parking replacement, insulation, slab, utilities, livability |
| Attached addition | ~$150,000–$250,000 | Foundation, roofline, structure, utility upgrades |
| Detached / casita | ~$200,000–$400,000+ | Site work, foundation, utility trenching, separate build |
| Per square foot | ~$125–$350+ | Smaller units cost more per square foot |
For a full breakdown by type and finish, see our Utah ADU cost guide.
Timeline, roughly:
A detached build often runs about 8–12 months from contract to completion, a garage conversion about 7–9 months, and a basement/internal ADU is often faster. Design and permitting usually add a couple of months up front. These are estimates, not guarantees — permitting, site conditions, and revisions can extend them.
Is your White City lot likely a fit? A quick feasibility scorecard
Use this before you request a single bid. It won't replace a formal review, but it will tell you whether you're in green-, yellow-, or red-flag territory across the factors a real feasibility check looks at.
| Factor | ✅ Green flag | ⚠️ Yellow flag | 🚫 Red flag |
|---|---|---|---|
| Jurisdiction | Property clearly in White City | Boundary unclear (near Sandy line) | Assuming Sandy or county rules apply |
| ADU type | Internal/basement path fits | Garage or attached needs design review | Detached assumed without checking current rules |
| Owner occupancy | You plan to live on the property | You might move later | Investor-only plan relying on renting both units |
| Lot / space | Room for the ADU type you want | Near a threshold | Too small for the intended path |
| Parking | Extra on-site parking available | Driveway changes needed | No way to add/replace required parking |
| Basement / garage condition | Existing layout helps | Egress, HVAC, or plumbing upgrades needed | Major structural or code barriers |
| Utilities | Existing capacity looks manageable | Upgrade possible but unknown | Water/sewer/electrical capacity looks prohibitive |
| Rental plan | Long-term rental or family use | Rental term unclear | Built around short-term (under-30-day) rental |
| Budget | Budget matches the ADU type | Budget is tight | Wants a detached unit on a basement-conversion budget |
| HOA / private restrictions | No private restriction found | Documents need review | A recorded restriction likely blocks it |
If you're mostly in green, you're a strong candidate to move forward. Mostly yellow means a feasibility review will save you real time. Any reds are exactly what you want to catch now, not after you've paid for plans.
What does the White City ADU permit path look like?
Think of it as a permitted construction-and-licensing project, in this order: feasibility, design and scope, permit application and plan review, inspections, and — if you'll rent it — business licensing. Skipping the permit step is not an option; unpermitted ADUs create safety, insurance, and resale problems.
- 1
Confirm jurisdiction, ADU type, and property fit.
Nail down whether your parcel is in White City, which ADU type is realistic, and your goal, budget, and timeline. This is what the feasibility step is for.
- 2
Confirm the current rule path.
Internal ADU rules are settled; detached rules are in transition. Verify what applies to your parcel under White City's current ordinance before you design to a specific size or placement.
- 3
Prepare plans and apply for the permit.
Permits for White City are handled through the MSD's building-permit process, including plan review and inspections. Depending on the scope of work, a licensed contractor may be required to pull the permit — confirm that requirement before construction.
- 4
Pass inspections and complete licensing.
If you'll rent the unit, you'll need the ADU permit plus a business license, renewed annually while it's rented (White City resident notice, June 2025).
How to choose a White City ADU builder without getting burned
Choose a builder after the ADU type and rule path are clear. The right builder for a basement apartment may not be the right builder for a detached casita, a garage conversion, or a prefab unit. Ask before you request a bid:
- Have you built or permitted ADUs in Salt Lake County / MSD-served communities?
- Will your bid include design, engineering, permit support, utility work, inspections, and finish allowances — and what's excluded?
- How do you handle egress, fire/safety, HVAC, and parking requirements?
- How do you price utility trenching or electrical upgrades?
- What happens if the city or MSD requires revisions?
- Are you licensed and insured for this scope, and who pulls the permits?
- What's the payment schedule and a realistic start date?
What not to trust:
Any "no permit needed" claim; quotes that ignore parking or owner occupancy; detached estimates that don't discuss utilities; rendered or AI-generated images presented as the builder's actual completed projects; "best builder" claims with no visible criteria; and prefab pricing that leaves out foundation, utilities, delivery/crane, permits, and site work.
When an ADU may not be the right move (yet)
Sometimes the smartest decision is to wait, shrink the scope, or choose something simpler. If your budget is too low for the ADU type you want, your rental plan conflicts with the rules, your lot can't support the parking or utilities, or a private restriction blocks it, forcing the project rarely ends well.
Reasonable alternatives to consider:
- –Finish part of the basement as living space without creating a legal rental unit.
- –Build a home office or studio instead of a full dwelling unit.
- –Wait for White City's detached-ADU rules to settle if a backyard unit is your goal.
- –Start with a smaller internal ADU scope.
- –Line up financing before you commit to design.
- –Shift a short-term rental idea to a long-term plan that actually complies.
None of that means an ADU is a bad idea — for the right lot and goal in White City, it can be a strong one. It just means the feasibility answer should come before the shovel.
White City ADU FAQ
Sources we checked
- Utah Property Rights Ombudsman — Accessory Dwelling Units (internal-ADU rules; impact-fee exemption, Utah Code §11-36a-202)
- Utah Legislature — Senate Bill 284 (2026); detached-ADU section Utah Code §10-21-304, effective October 1, 2026
- White City — June 2025 resident notice (Internal Accessory Dwelling Units and Short-Term Rentals; city of the fifth class)
- Greater Salt Lake Municipal Services District — White City / planning services
- Salt Lake County Office of Regional Development — ADU guidance (context only — not White City's governing ADU ordinance)
Rules and costs change. If you're relying on anything here for a real decision, confirm the current White City ordinance and get a property-specific review first.
Utah ADU Builders Editorial Team — Last verified: June 2026.