Utah County · 19,902 residents
Highland ADU rules
Highland: internal ADUs allowed; detached ADUs allowed with conditions (lot 11,000+ sq ft). Owner occupancy applies.
Internal ADU (inside the home)
Detached ADU (backyard building)
Not yet fully verified · last reviewed September 7, 2026 See sources
Highland ADU rules at a glance
| Rule | Internal ADU (basement, attic, inside the home) | Detached ADU (backyard building) |
|---|---|---|
| Allowed? | Allowed | Allowed with conditions |
| Minimum lot | Not yet verified — confirm with the city | 11,000 sq ft. State floor ≥11,000 sq ft from 2026-10-01; city drafting local ordinance |
| Owner occupancy | Required for ADU framework discussed with DADUs (owner in ADU or main) | Required (ADU or main) |
| Parking | Not yet verified — confirm with the city | State caps: 1 if <650 sq ft, 2 if ≥650 |
| Size limits | Not yet verified — confirm with the city | Council direction Aug 18, 2026: living area max 1,250 sq ft (<1 acre) and preference to allow 1,500 sq ft (≥1 acre), plus accessory building lot-coverage % by zone and footprint ≤ primary home footprint — confirm final adopted ordinance |
| Height | Not yet verified — confirm with the city | Accessory building height 25 ft discussed; rear setback may reduce to 20 ft if 1 story / 15 ft height |
| Setbacks | Not yet verified — confirm with the city | Proposed: same as home (30' front, 15' side / 30' streetside, 30' rear) with optional 20' rear if ≤1 story/15' height |
| Zones | Not yet verified — confirm with the city | R-1-20/30/40 and Open Space coverage % rules discussed |
| Permit process | Register/record ADU; cannot subdivide/sell unit separately (per council DADU framework) | 1 ADU per lot (internal or detached, not both); register/record; no separate utilities but separate address marker; ordinance returning for adoption after Aug 18 direction |
State law: detached ADUs from October 1, 2026
Highland is a “specified municipality” under Utah S.B. 284. Beginning October 1, 2026, it must permit one detached ADU as a permitted use on a lot of 11,000 sq ft or more that has a detached single-family home. The city can still apply setbacks, height, design, owner-occupancy and limited parking rules, and it may allow detached ADUs on smaller lots. How the state ADU laws work.
How our property map screens Highland lots
The map colors parcels using the rules on this page and the recorded lot size. A color is a planning screen, not a permit; Highland makes the decision.
- "Likely" above 15,000 sq ft is this site's planning band for a large recorded lot. It is not a sentence in the Highland code. Owner occupancy, parking, setbacks, zones, and HOA rules below still have to be checked.
Planned communities, PRDs and PUDs
Reviewed on September 22, 2026 against this city's research file, its published ADU page where one was found, and Utah meeting packets. No adopted sentence was confirmed that allows or bans an ADU in every PUD, PRD, PRUD, or planned community. If the assessor class or subdivision name says PUD, PRD, PRUD, planned unit development, planned residential development, planned community, resort community, or master planned community, the map keeps that lot highly unlikely regardless of size. A plat, CC&Rs, or development agreement can still prohibit an ADU where the zone allows one.
Planning notes for Highland
Highland requires registration for new and existing ADUs, together with any applicable building permit. Its process includes an owner-occupied statement and final approval before registration is complete. If a basement already has a kitchen, bring its permit history so we can help identify what is needed to legalize or update the space.
Bring these to your review
- Existing permits and any certificate of occupancy
- Floor plan and photographs of the current unit
- Owner-occupancy information for the required statement
The question to resolve first
Is this a new ADU application, or an existing unit that needs permits and registration completed?
Sources
We link only to government sources and public meeting records. Codes change; confirm the current version with Highland before you apply.
- Highland Building Department
Published city guidance for new and existing ADUs
- Utah S.B. 284 (2026), enrolled bill
Statewide detached-ADU requirements for specified municipalities, operative October 1, 2026.
- Official Highland website
Common Highland ADU questions
Can you build an ADU in Highland?
Highland: internal ADUs allowed; detached ADUs allowed with conditions (lot 11,000+ sq ft). Owner occupancy applies. This is planning guidance, not a permit. Confirm the zone on your parcel with Highland.
What lot size does Highland require for an ADU?
Internal ADU: Not yet verified — confirm with the city. Detached ADU: 11,000 sq ft minimum. State floor ≥11,000 sq ft from 2026-10-01; city drafting local ordinance.
Does Highland require the owner to live on the property?
Internal ADU: Required for ADU framework discussed with DADUs (owner in ADU or main). Detached ADU: Required (ADU or main).
How much parking does a Highland ADU need?
Internal ADU: Not yet verified — confirm with the city. Detached ADU: State caps: 1 if <650 sq ft, 2 if ≥650.
What does it cost to build an ADU in Highland?
Wasatch Front planning bands are often about $55,000–$145,000 for an internal suite, $70,000–$175,000 for a garage conversion, and $95,000–$250,000 or more for a new detached unit, before unusual site work. These are planning ranges, not bids.
Can an HOA block an ADU in Highland?
City approval does not override CC&Rs or plat notes. Read the HOA documents and your subdivision plat before you design. A private restriction can stop a unit the city would otherwise allow.
Before you design: general checks for any Utah ADU
General planning advice, not Highland code.
- Confirm the zoning district on the city zoning map. The county assessor’s “residential” class is not zoning.
- Read your HOA CC&Rs and subdivision plat notes; private restrictions can block a unit the city allows.
- Sketch existing and proposed parking. Driveway geometry and access often decide what fits.
- Ask early about sewer, water and electrical capacity; utilities can force a redesign.
- Expanding a building’s footprint usually triggers full setback and height rules.
Nearby city ADU rules
Want to know what fits on your Highland lot?
Free, no obligation. We review your parcel against these rules and, if you want, introduce independent design and construction partners. Partners may pay us for referrals.
Utah ADU Builder provides educational planning guidance. This page is not legal advice and not a permit. Population: UGRC POPLASTESTIMATE / Census-derived municipal estimates (manual fill where UGRC blank). Editorial standards.