By the Utah ADU Builders Editorial Team · Last verified: July 11, 2026
Sandy ADU Builders: Costs, City Rules, and How to Hire in Sandy, Utah (2026)
Sandy allows one kind of rentable ADU today: an internal accessory apartment inside your owner-occupied home, approved through a building permit, an administrative special use permit, and an annually renewed business license. Detached backyard ADUs are the 2026 story — Utah's SB 284 requires cities like Sandy to open a detached path for qualifying lots of 11,000+ square feet starting October 1, 2026, with Sandy's local standards still taking shape. Plan on roughly $60,000–$150,000+ for a basement or internal conversion; a future detached unit adds substantially more.
Best fit: owner-occupants who want long-term rental income or housing for family — or who want to be ready to act when Sandy publishes its detached standards.
Not a good fit: investors who won't live on the property (Sandy's current rentable path requires owner occupancy), anyone counting on short-term rental income, or anyone who needs a guaranteed approval or price before feasibility is checked.
Sandy's four accessory living paths at a glance
Sandy City's code runs on its own vocabulary: its operative category is the "accessory apartment," which the code itself defines as an internal accessory dwelling unit, or I-ADU (Sandy Land Development Code Sec. 21-37-2). Around it, the code defines three more accessory living categories — and picking the wrong one is the most expensive mistake a Sandy homeowner can make. Here's the map, current as of July 2026:
| What Sandy calls it | Can you rent it? | Status in Sandy today | The conditions that matter |
|---|---|---|---|
| Accessory apartment (internal ADU — basement or in-home suite) | Yes — long-term | Allowed now by administrative special use permit in most single-family zones | Owner must live on-site; business license renews every year; one extra off-street parking space; approval ends when you sell |
| Extended living area (in-home family suite) | Not under its base approval — family and non-paying guests only | Allowed now — the simplest path | Approved at building-permit review; recorded with the county; unlike an accessory apartment, it does transfer to the next owner |
| Guesthouse (small detached structure) | Not under its base approval — non-paying guests only | Lots of 20,000+ sq ft only | Max 400 sq ft, one bedroom, single story, kitchenette only (no full kitchen), no basement |
| Detached rentable ADU (backyard cottage) | Long-term, once rules land | Not in Sandy's current code | Utah's SB 284 opens a path for qualifying 11,000+ sq ft lots on October 1, 2026. Sandy's implementing standards had not been adopted as of our July 2026 review. |
Sources: Sandy City Land Development Code Secs. 21-7-2 and 21-11-1; Utah SB 284 (2026). Full source list at the end of this guide.
The fastest way to find out which row is realistically yours — before you pay for plans or sit through sales pitches — is a property-specific check.
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Can you build an ADU in Sandy right now?
Yes — an internal one. Sandy's current code allows an accessory apartment inside an owner-occupied single-family home, approved through the Community Development Department. What Sandy does not currently allow is a detached unit you can rent as a long-term home: the code states an accessory apartment "shall not occupy any accessory buildings," and Sandy's only detached category — the guesthouse — is non-rental under its base approval.
What Sandy means by "accessory apartment"
Sandy's code defines an accessory apartment as an internal accessory dwelling unit: a self-contained unit — its own kitchen, bathroom, and sleeping area — built entirely within an owner-occupied single-family home. Think basement apartment with a side entrance, or a main-level suite carved out of a larger home. Utah law uses the same core concept: under Utah Code § 10-21-303, one internal ADU is a permitted use in areas zoned primarily for residential use, subject to specific restrictions the city may impose.
Two structural rules in Sandy's code deserve early attention:
Is your zone eligible?
Eligibility runs through your zoning district, not a single magic lot-size number. Sandy's permitted land use matrix lists accessory apartments as a special use across its R-1 single-family districts — from R-1-40 down through R-1-6 — and in R-2-10, R-2-8, RM, and PUD areas, where they're limited to detached single-family developments (Sandy LDC Sec. 21-7-2). Mobile homes are excluded outright; Sandy's code prohibits creating an accessory apartment or extended living area in a mobile home. Look up your zone in Sandy's online GIS before spending money on plans.
Why Sandy's answer is different from Salt Lake City's
Ten miles north, Salt Lake City runs an established ADU program that includes detached backyard units with published setback and height standards. Sandy took a different road: internal accessory apartments plus a strictly limited guesthouse category. If you've been reading general "Utah ADU" articles — most of which are really Salt Lake City articles — that's the disconnect. It's also why hiring a builder who has actually worked Sandy's process matters more than hiring the one with the nicest website or the most ADU-adjacent marketing.
What changes for detached ADUs in Sandy on October 1, 2026?
Utah's SB 284, signed in 2026, requires covered Utah cities — Sandy among them — to allow a detached ADU as a permitted use on qualifying lots beginning October 1, 2026. A qualifying lot is generally at least 11,000 square feet with an existing single-family home, in an area where single-family homes are permitted. This is a genuine turning point for Sandy, where a rentable detached unit has had no path at all. It is not, however, automatic approval of anything.
What the state law does — and what it leaves to Sandy
The statute forces the door open; Sandy still builds the frame. Under the new law, cities keep meaningful authority over the details that make or break real projects: unit size and dimensions, height, lot coverage, setbacks (the required distance between a structure and property lines), design standards, owner-occupancy requirements, prohibiting rentals shorter than 90 days, requiring replacement parking when a detached garage is converted, limiting a property to one ADU, and reviewing utility capacity. Sandy may also require that the ADU design be compatible with the primary dwelling's architecture — something that can shape cost, timeline, and what builders are actually qualified to deliver.
That list deserves a slow read, because each item is a lever Sandy can pull. A lot can clear 11,000 square feet and still fail on setbacks, easements, utility capacity, or the shape of the buildable area behind the house.
Where Sandy stood as of July 2026
Sandy publicly discussed detached-ADU implementation at a City Council work session in April 2026, and the council had debated the concept as far back as 2024. As of our July 2026 review, we could not locate a final adopted Sandy ordinance implementing the detached-ADU law. Until Sandy adopts its standards, nobody can tell you the final size cap, setbacks, design rules, or owner-occupancy terms a Sandy detached ADU will carry — anyone presenting Sandy-specific detached standards as final, before Sandy publishes them, is filling in blanks with guesses.
Future-effective law is not present-day permission. An 11,000-square-foot lot is an eligibility screen, not a guarantee. Building code, fire code, utility capacity, easements, setbacks, and Sandy's final standards all still apply on the day you actually submit.
One more planning wrinkle worth knowing
The state framework lets cities limit a property to one ADU. If you build an internal accessory apartment this year, don't assume you can stack a detached unit on top of it later — that depends on the rules Sandy adopts. If the detached unit is your real goal, say so during feasibility, because it changes the smart sequencing.
The smart play between now and October 1
If a detached unit is what you actually want, the window before the effective date is for homework, not construction: confirm your lot and zone, get a read on utilities and site access, understand your budget band, and line up your builder conversation — so you're prepared to evaluate, and apply, as soon as Sandy publishes its final standards and application process, instead of starting your research the week they land. That pre-work is exactly what a feasibility review front-loads.
How much does an ADU cost in Sandy?
There is no official "Sandy average," and you should distrust any page that claims one. What we can give you honestly are Utah planning ranges, drawn from our statewide cost research and current as of our last cost check: roughly $60,000–$150,000+ for a basement or internal conversion and $200,000–$400,000+ for a detached, site-built unit, with garage conversions and attached additions falling between.
| Project type | Utah planning range (2026) | What swings the number most |
|---|---|---|
| Basement / internal accessory apartment | $60,000–$150,000+ | Condition of the existing space, egress windows (code-required emergency exits for basement bedrooms), fire separation, plumbing runs, electrical panel capacity |
| Garage conversion (attached) | $60,000–$175,000+ | Whether the space can qualify as an internal unit for your layout, replacing the parking you're removing, insulation and structural work |
| Attached addition | $150,000–$275,000+ | Foundation, roofline tie-in, matching Sandy's design-compatibility rules |
| Detached site-built ADU | $200,000–$400,000+ | A future Sandy path — site work, foundation, utility trenching, access, and whatever standards Sandy adopts |
These are estimates for planning, not bids. They assume design, permits, standard finishes, and utility connections; they do not assume your specific site. Full assumptions and current figures live in our Utah ADU cost guide — if the two pages ever disagree, the cost guide is the canonical, most recently updated source.
What moves the number on a Sandy lot
A few cost drivers deserve early attention on some Sandy properties: parts of the east bench can hit rock or steep grade during excavation, turning a simple dig expensive; basements often need new egress windows cut through concrete; older electrical panels may not carry a second kitchen without an upgrade; and Sandy's parking rule means that if your project modifies required parking (a garage conversion is the usual suspect), you must replace that parking on-site. One more that catches people off guard: if your home is on a septic system, Sandy requires proof from a licensed professional that it's working properly — or connection to sewer (Sandy LDC Sec. 21-11-1). On an older system, that single line item can reshape the budget.
Why two quotes for the "same" project can be tens of thousands apart
Usually it isn't padding — it's scope, assumptions, risk pricing, overhead, scheduling, and exclusions. One bid includes design, engineering, and permit handling; the other assumes you bring finished plans. One assumes your panel and sewer line are fine; the other prices the upgrade. One carries a real finish allowance; the other carries a placeholder. Before comparing prices, force every bid onto the same scope — there's a checklist for exactly that in the builder section below.
Free screen first: your likely build path and a planning cost range — then, where appropriate, an introduction to a matched local builder for a real, scoped bid.
What are Sandy's published 2026 permit and license fees?
Sandy's 2026 Consolidated Fee Schedule itemizes the city-side costs: a $232 special use permit fee, a $282 initial accessory-apartment business license (inspection included), and a $105 annual renewal. The building permit itself is valuation-based, with a plan-review charge of 65% of the total permit fee and a 1% state surcharge on top. These are published fee components — not your project's total.
| 2026 fee item (Sandy City) | Amount / method |
|---|---|
| Special use permit | $232 |
| Accessory apartment business license — initial (includes inspection) | $282 |
| Business license — annual renewal | $105 |
| Building permit, project valuation under $50,000 | $624 |
| Building permit, $50,000–$100,000 valuation | $1,739 |
| Building permit, $100,000–$500,000 valuation | $2,332 |
| Plan review | 65% of total permit fee |
| State surcharge | 1% of total permit fee |
Source: Sandy City 2026 Consolidated Fee Schedule. Higher valuation tiers exist for larger projects. Don't add every row and call it "the Sandy ADU permit cost" — your building permit fee depends on your project's valuation, and recording, professional, utility, and construction costs sit on top of city fees. Fee schedules change; confirm the current schedule at application.
How does Sandy's approval process actually work?
Sandy's accessory apartment approval is a set of required components with a few fixed sequence points: a building permit before any construction, an administrative special use permit from Community Development, proof of recordation with the Salt Lake County Recorder before occupancy, and a valid business license before the unit is rented — renewed every year after. The special use permit and business license are interdependent: lose either one and the other is invalidated.
- Confirm the property qualifies. Zoning district, ownership structure, owner occupancy, parking, and the physical layout question — can a self-contained unit work within your home with a compliant entrance? This is the stage where a feasibility review earns its keep, before money goes to plans.
- Design it and secure the building permit. Sandy requires all building permits before construction, and the unit must meet the city's adopted building, fire, and health codes. Expect to submit a scaled site plan, architectural elevations, and a room-by-room description of which parts of the home become the apartment.
- Complete the administrative special use permit. This is where owner occupancy gets proven — and Sandy is specific about it. The fee title owner must be an individual or the trustor of a family trust holding at least 50% ownership; corporations, partnerships, and LLCs cannot hold the property and get this permit. You'll present your most recent state and federal tax returns listing the property as your primary residence, a government-issued ID showing the address, and a notarized affidavit that you live there (Sandy LDC Sec. 21-11-1).
- Build, pass inspections, and record. Approval is recorded with the Salt Lake County Recorder — including a reversion clause spelling out that the space becomes a non-rental extended living area if the permit ever expires. Proof of recordation is required before occupancy.
- Hold the business license, then rent. The accessory apartment business license expires January 1 each year and must be renewed annually. Miss the renewal and the special use permit goes with it.
The rules that surprise Sandy homeowners
A handful of provisions in Sandy's code routinely blindside people mid-project, so meet them now: the apartment gets no separate address and no additional mailbox. No separate utility connections or meters — though a private submeter behind your primary meter, inside the dwelling, may be allowed for tracking a tenant's usage. The occupants must be one additional single family, and your tenant cannot sublease any portion of the unit. You need at least one additional off-street parking space for the apartment's occupants, beyond what your household needs, and your tenant's additional vehicles must fit on-site — on-street parking is for visitors only.
And the one that matters when you sell
The special use permit is not transferable. It expires when the property sells, when you stop living there as your primary residence, or when the business license lapses — and the space legally reverts to an extended living area (family and non-paying guests only). A buyer who wants rental income applies fresh (Sandy LDC Sec. 21-11-1). The physical improvements stay with the house either way; how a future buyer or appraiser values them depends on permitted status, layout, construction quality, and the market — but the rental permission itself doesn't ride along. Worth knowing before you build primarily with resale in mind. (Interesting contrast: an extended living area approval, the non-rental version, does transfer to the next owner.)
How long does all this take?
We're not going to invent a number. We haven't found a current, published Sandy dataset on permit turnaround, and any "6–10 weeks" figure you see elsewhere is somebody's guess dressed up as data. What's honest: your timeline is the sum of design and engineering, Sandy's plan review and any correction cycles, construction, inspections, recordation, and licensing — and it moves with submittal completeness, municipal workload, engineering coordination, contractor scheduling, utility work, and whatever's hiding inside existing walls. The lever squarely in your hands is a complete, well-prepared application.
Can you rent out a Sandy ADU — long-term or on Airbnb?
Long-term, yes: that's exactly what a permitted accessory apartment is for, as long as you live on-site and keep the license current. Short-term is a separate, harder question. Sandy prohibits renting an accessory apartment, extended living area, or guesthouse for periods under 30 consecutive days unless the property also obtains short-term rental (STR) approvals — a distinct special use permit and STR business license with their own owner-occupancy proof (Sandy LDC Secs. 21-11-1 and 21-11-26). That under-30-day prohibition covers all three accessory living categories alike.
Two things make Sandy's STR path unreliable as a business plan. First, permits are capped: each Sandy community gets a base of two STR permits plus one per 100 single-family detached homes, recalculated every two years, with a waiting list once a community is full. Second, enforcement has teeth: violations carry fines that Sandy's current materials list at up to $1,000 per violation, along with permit revocation and a two-year ineligibility period for repeat offenders.
How should you compare Sandy ADU builders?
Choose the builder after you know what you're building — then verify, don't trust. The right Sandy ADU builder is a Utah-licensed contractor whose license you've personally confirmed, who has taken projects through Sandy or neighboring Salt Lake County reviews, and who will price the same written scope as every other bidder.
Verify the license yourself — it takes two minutes
Look up the exact business name on the contract in the Utah Division of Professional Licensing (DOPL) Licensee Lookup at secure.utah.gov/llv. Confirm the license is current on the date of the estimate, the classification fits the work being offered, and the entity on the license matches the entity you'd be paying. A Houzz badge, a glossy portfolio, or an out-of-state license is not Utah verification. Neither is our word, or anyone else's — check it yourself, every time.
Ask the questions that expose Sandy experience
Generic remodeling experience is not accessory apartment experience. Ask: Have you taken an accessory apartment through Sandy's special use process, or comparable reviews nearby? Who handles the permit submittals and correction responses — you or me? How do you design around Sandy's entrance-visibility rules, and how do you handle the connectivity question with the city? What's your plan if my panel or sewer line can't carry the unit? How do you price concealed conditions in an existing basement? A builder who has done this work answers in specifics. A builder who hasn't answers in adjectives.
Force every bid onto the same scope
Two estimates are only comparable when they price the same project. Before you compare dollar to dollar, make each bid state plainly whether it includes:
| Each bid must explicitly address… | ✔ |
|---|---|
| Design and drawings | |
| Structural engineering | |
| Energy / code documentation | |
| Permit fees — and who pulls the permits | |
| Demolition | |
| Foundation or structural work | |
| Egress windows and fire separation | |
| Plumbing, electrical, and HVAC — including panel or service upgrades if needed | |
| Utility trenching or connections | |
| Finishes with named allowance amounts | |
| Cleanup and inspection completion | |
| A stated contingency | |
| A written list of exclusions |
Any line a bid is silent on can come back later as an owner cost, a thin allowance, or a change-order dispute.
Red flags that end the conversation
- "Permit guaranteed." Any one of these is a no.
- An "all-in" price with no written scope. Any one of these is a no.
- A big deposit against little completed work. Any one of these is a no.
- No named contracting entity, or a name that doesn't match the license. Any one of these is a no.
- Rental-income projections used as a sales tool. Any one of these is a no.
- Pressure to sign before your property's feasibility has been checked. Any one of these is a no.
Design-build, general contractor, or prefab?
All three delivery models can serve Sandy's current internal projects — a design-build firm carries plans and construction under one roof, a general contractor builds from plans you source, and factory-built or modular units are assembled off-site and finished on your lot. For a rentable detached or factory-built unit, everything still runs through Sandy's future detached standards and your parcel's feasibility. And prefab pricing deserves extra scrutiny either way: the attractive number is often the unit, with foundation, transport, crane, utility connections, and site work sold separately.
We start with your property and likely build path, then — where it makes sense — introduce you to a matched local builder for a scoped estimate. We may receive compensation for that introduction; it never changes the feasibility answer you get.
When is an ADU the wrong move in Sandy?
An ADU is not automatically a smart project just because Utah has become more ADU-friendly. In Sandy, the right answer still depends on your lot, your ownership structure, your utilities, your budget, and rules that are actively changing this year. Some honest stop signs:
- You won't live on the property. Sandy's current rentable path — the accessory apartment — requires owner occupancy, proven with tax returns and a notarized affidavit, and the permit dies when you move out or sell. Whether Sandy imposes owner occupancy on future detached units is the city's call under the state law; its final ordinance will say.
- The property sits in an LLC or corporation and you intend to keep it there. Sandy's code bars those entities from holding the accessory apartment permit.
- Your plan needs Airbnb income to pencil. Capped permits, waiting lists, and fines up to $1,000 per violation are not a foundation for a six-figure build.
- Your lot is under 11,000 square feet and your home has no convertible interior space. The new detached path may simply not reach you — Sandy could choose to allow smaller lots, but the state law doesn't require it.
- Your budget can't absorb a 15–20% overrun. Basements hide surprises; hillside lots hide bigger ones.
- A recorded covenant or HOA restriction targets your project type. Utah law limits how far a community association can go in blocking a code-compliant internal ADU or its rental — but detached structures, short-term rental use, and exterior changes can still run into enforceable private restrictions. Pull your CC&Rs early and read them against your specific project, or have someone qualified do it.
If one of those is you, the cheapest possible outcome is finding out now. A feasibility review that returns "not yet" or "not this type" costs you nothing and can keep you from paying for plans before basic feasibility has been screened.
What we verified for this guide
We wrote this from primary sources, and we'll tell you exactly which ones. For Sandy's current rules, we reviewed the Sandy City Land Development Code provisions governing accessory apartments, extended living areas, and guesthouses (Sec. 21-11-1), the residential permitted land use matrix (Sec. 21-7-2), and the short-term rental section (Sec. 21-11-26), along with Sandy's approved 2026 Consolidated Fee Schedule. For state law, we reviewed the full current text of Utah's internal-ADU statute (Utah Code § 10-21-303), the impact-fee limitation (§ 11-36a-202), and the enrolled text and official summaries of SB 284 from the 2026 General Session. For local status, we reviewed Sandy City Council public records, including the April 2026 detached-ADU work session.
Where Sandy's published text and current state law point in different directions — notably on internal connectivity — we say so in the relevant section rather than pick a side for you. Cost figures are our editorial planning ranges built from statewide Utah research, not official Sandy averages, and we used no forums, reviews, or builder marketing as evidence for any law, cost, or permitting claim. Found something out of date? Tell us through the site's contact page and we'll re-verify.
Sandy ADU questions, answered
Sources
- 1Sandy City Land Development Code, Sec. 21-7-2 (Permitted Land Use Matrix), Sec. 21-11-1 (Accessory Apartments, Extended Living Areas, and Guesthouses), and Sec. 21-11-26 (Residential Short-Term Rental)
- 2Sandy City 2026 Consolidated Fee Schedule (approved)
- 3Utah S.B. 284 (2026 General Session), enrolled — Utah Legislature
- 4Utah Code § 10-21-303 (internal accessory dwelling units) — current text, Utah Legislature; and § 11-36a-202 (impact fee limitation)
- 5Utah Division of Professional Licensing, Licensee Lookup
- 6Sandy City Council public meeting records (detached-ADU work session, April 2026)
This guide is educational information for Utah homeowners, not legal, tax, engineering, or financing advice. Rules and fees change; always confirm current requirements with the applicable official source before making decisions.
Last verified: July 11, 2026