Utah County · 54,149 residents
Eagle Mountain ADU rules
Eagle Mountain: internal ADUs allowed; detached ADUs allowed (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
Eagle Mountain ADU rules at a glance
| Rule | Internal ADU (basement, attic, inside the home) | Detached ADU (backyard building) |
|---|---|---|
| Allowed? | Allowed | Allowed |
| Minimum lot | Not yet verified — confirm with the city | 11,000 sq ft |
| Owner occupancy | Owner must live in primary or ADU except bona fide temporary absences | Required (primary or ADU) |
| Parking | 2 off-street hard-surface spaces for ADU tenants (driveway in front of garage generally does not qualify unless ADU is in that garage and primary garage parking is replaced elsewhere) | 2 off-street hard-surface spaces for ADU |
| Size limits | Not yet verified — confirm with the city | Living space 400–1,200 sq ft; max 2 bedrooms |
| Height | Attached ADUs meet primary setbacks/height of zone | Above garage: max 35 ft; standalone: max 2 stories and 35 ft |
| Setbacks | Basement/attached: separate exterior entrance on side or rear; attached additions meet primary setbacks (EMMC 17.25.040) | Same front/side/rear as primary dwelling; ≥6 ft from primary |
| Zones | Where permitted by EMMC 17.25.030 | Cottage/casita/guest house where permitted by 17.25.030; architectural compatibility required |
| Permit process | ADU permit from Planning + building permit; Planning Director approval path for compliant applications; PC path for exceptions | ADU permit + building permit; permanent foundation; utilities may be separate meters in owner's name; address Unit B |
What the Eagle Mountain council decided
Recorded votes and actions on ADU rules, linked to the public meeting record on OpenUtah.
· Planning Commission · Tabled
Planning Commission tabled a code amendment so staff could revisit its animal, ADU and home business tables; the item did not advance that night.
Read the meeting record· Planning Commission · Approved
Planning Commission approved the Atkinson accessory dwelling unit exception.
Read the meeting record· Planning Commission · Tabled
Planning Commission tabled the Atkinson ADU exception to give the applicant time to review city ordinances.
Read the meeting record
State law: detached ADUs from October 1, 2026
Eagle Mountain 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 Eagle Mountain 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; Eagle Mountain 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 Eagle Mountain 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 Eagle Mountain
Eagle Mountain routes Planning and Building applications through OpenGov and lists ADU permits alongside basement/walkout and accessory-building permits. Select the ADU use explicitly: approval to finish a basement or build an accessory structure does not by itself establish approval for a separate dwelling.
Bring these to your review
- Existing permit numbers for a basement or accessory structure
- Proposed kitchen, bathroom and entrance layout
- ADU application category and related construction permits
The question to resolve first
Which ADU use approval is needed in addition to the basement, walkout or accessory-building permit?
Sources
We link only to government sources and public meeting records. Codes change; confirm the current version with Eagle Mountain before you apply.
- Eagle Mountain official site — Planning & Building applications
Published city application directory
- Utah S.B. 284 (2026), enrolled bill
Statewide detached-ADU requirements for specified municipalities, operative October 1, 2026.
- Official Eagle Mountain website
Common Eagle Mountain ADU questions
Can you build an ADU in Eagle Mountain?
Eagle Mountain: internal ADUs allowed; detached ADUs allowed (lot 11,000+ sq ft). Owner occupancy applies. This is planning guidance, not a permit. Confirm the zone on your parcel with Eagle Mountain.
What lot size does Eagle Mountain require for an ADU?
Internal ADU: Not yet verified — confirm with the city. Detached ADU: 11,000 sq ft minimum.
Does Eagle Mountain require the owner to live on the property?
Internal ADU: Owner must live in primary or ADU except bona fide temporary absences. Detached ADU: Required (primary or ADU).
How much parking does a Eagle Mountain ADU need?
Internal ADU: 2 off-street hard-surface spaces for ADU tenants (driveway in front of garage generally does not qualify unless ADU is in that garage and primary garage parking is replaced elsewhere). Detached ADU: 2 off-street hard-surface spaces for ADU.
What does it cost to build an ADU in Eagle Mountain?
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 Eagle Mountain?
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 Eagle Mountain 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 Eagle Mountain lot?
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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.