Eagle Mountain has one of the more flexible ADU policies in Utah County — and that's a meaningful advantage for homeowners considering a rental unit, an in-law suite, or a detached backyard apartment.
Unlike Saratoga Springs, which only allows internal ADUs and prohibits detached structures entirely, Eagle Mountain permits both internal and detached accessory dwelling units. You can add a basement apartment inside your home or build a separate unit above a garage or in your backyard — subject to the requirements below.
Here's everything the city's official code says, sourced directly from Eagle Mountain Municipal Code Chapter 17.70 — Accessory Dwelling Units.
What Eagle Mountain Allows
Per Eagle Mountain Municipal Code Chapter 17.70, accessory dwelling units are a permitted use in the following residential zones: A, RR, RA-5, R1-40, R1-20, R1-10, R1-9, R2-8, R3-6, MF-10, MF-14, MF-18, MR, and PC zones — subject to all applicable standards.
Three types of ADUs are permitted:
- Internal ADU — a basement apartment or unit created within the footprint of the existing home
- Attached ADU — an addition connected to the primary dwelling
- Detached ADU — a separate structure on the same lot, such as a backyard unit or an apartment above a detached garage (maximum height: 35 feet above a detached garage, per Eagle Mountain Residential Zone Code Chapter 17.25)
The Requirements at a Glance
Owner occupancy: Per Chapter 17.70, the owner of the property must live in either the primary unit or the ADU. Bona fide temporary absences are allowed with documentation.
One ADU maximum per lot: Only one accessory dwelling unit is permitted per property.
Occupancy limits: The occupants of the ADU must be related to each other by blood, marriage, or adoption — or consist of no more than two unrelated individuals living as a single housekeeping unit. Subleasing a portion of the ADU to other individuals is not permitted.
Single-family appearance: The ADU must be incorporated into or designed so the property maintains the appearance of a single-family residence to the degree reasonably feasible. All entrances to ADUs must be located on the side or rear of the building — not the front. For detached ADUs, architectural style, materials, and colors must be compatible with the primary dwelling.
Utilities: Detached ADUs may have separate utility meters. All municipal utilities must be in the property owner's name, and the owner is responsible for all utility payments.
No short-term rentals: Per Chapter 17.70: "Accessory dwelling units may not be rented for a period of less than 30 consecutive days." Airbnb and VRBO-style rentals are not permitted.
Transfer of ownership: When a home with an ADU is sold, the ADU permit remains valid as long as the unit continues to comply with city ordinances. The new owner assumes full responsibility for compliance.
Permits: Required Before Construction and Before Occupancy
Per Chapter 17.70, an ADU permit from the Planning Division of the Community Development Department is required — in addition to any required building permit — before construction, remodeling, or occupancy.
This includes:
- New construction ADUs
- Converted spaces (finished basements, garage conversions)
- Previously finished basements that were completed without a permit — you must obtain permits for the prior work before the ADU can be approved
Contact Eagle Mountain Community Development at 801-789-6609 or visit eaglemountaincity.com to start the permitting process.
What happens without a permit: Any person constructing or causing the construction or remodeling of a residence for an ADU without a permit is in violation of city code. Permits are required before occupancy — not after. Failure to comply can result in permit revocation by the planning director.
HOA Rules Still Apply
Even if your property is in an approved zone, your HOA may have additional restrictions. Per Utah's Property Rights Ombudsman, where an internal ADU would not violate a local ordinance or building, health, or fire code, "renting an Internal ADU may also not be prohibited by any private community association by CC&R or HOA rule." However, detached ADUs and other ADU types may still be subject to HOA restrictions depending on your specific CC&Rs.
Always review your CC&Rs and confirm with your HOA before starting any ADU project. As I covered in my Eagle Mountain HOA guide, Eagle Mountain has a wide range of HOA structures — and what one community allows, another may prohibit.
How Eagle Mountain Compares to Saratoga Springs
This is the key difference for buyers evaluating both cities with ADU potential in mind:
| Eagle Mountain | Saratoga Springs | |
|---|---|---|
| Internal ADUs | ✅ Allowed | ✅ Allowed (zone-dependent) |
| Detached ADUs | ✅ Allowed | ❌ Not permitted |
| Short-term rentals | ❌ Not allowed | ❌ Not allowed |
| Owner occupancy required | ✅ Yes | ✅ Yes |
| HOA may restrict | ✅ Yes | ✅ Yes |
If the ability to build a detached unit is important to you — a backyard apartment, a garage conversion, an in-law suite as a separate structure — Eagle Mountain is the better market for that strategy.
Before You Buy or Build
If you're considering an Eagle Mountain home specifically for its ADU potential:
- Confirm your zone — ADUs are permitted in most but not all Eagle Mountain residential zones
- Review your HOA CC&Rs — HOA restrictions may apply even where the city permits ADUs
- Check whether any existing basement apartment is permitted — unpermitted units require retroactive permitting before an ADU permit can be issued
- Contact Eagle Mountain Community Development at 801-789-6609 to confirm eligibility for your specific property
- Get your permit before occupancy — not after
As I covered in my guide to renting your Eagle Mountain home, rental income can be a powerful wealth-building strategy — but only if the unit is properly permitted and compliant from day one.
Questions About ADUs in Eagle Mountain? Let's Chat →
Related reading:
- Can You Add a Basement Apartment in Saratoga Springs? The Complete 2026 ADU Guide
- Two HOAs in Eagle Mountain: What It Means and What It Costs
- Eagle Mountain HOA Closing Costs: The Reinvestment Fee Explained
- Can You Park an RV or Boat in Your Eagle Mountain Driveway?
Sources: Eagle Mountain Municipal Code Chapter 17.70 — Accessory Dwelling Units (Ord. O-03-2024, O-33-2023, O-17-2023, O-41-2021); Eagle Mountain Municipal Code Chapter 17.25 — Residential Zones, detached ADU height limits; Utah Property Rights Ombudsman — ADUs and HOA restrictions.
Frequently Asked Questions
Does Eagle Mountain allow ADUs? Yes — Eagle Mountain permits internal, attached, and detached accessory dwelling units in most residential zones. This is more permissive than Saratoga Springs, which only allows internal ADUs and prohibits detached structures entirely.
Can I build a detached backyard unit in Eagle Mountain? Yes — detached ADUs are permitted in Eagle Mountain's residential zones, including units above a detached garage (maximum height 35 feet above garage). The unit must match the architectural style, materials, and colors of the primary dwelling, and all entrances must be on the side or rear of the property.
Can I use an ADU for Airbnb or short-term rental in Eagle Mountain? No. Eagle Mountain Municipal Code Chapter 17.70 explicitly prohibits ADUs from being rented for less than 30 consecutive days. Short-term rentals are not permitted.
Do I need a permit before finishing my basement as an ADU? Yes — and if your basement was finished previously without a permit, you must obtain those permits retroactively before an ADU permit can be issued. Contact Eagle Mountain Community Development at 801-789-6609.
Do I have to live in the home if I have an ADU? Yes. Owner occupancy is required — either in the primary unit or in the ADU. Bona fide temporary absences are permitted with documentation.
Can my HOA prohibit an ADU even if the city allows it? For internal ADUs specifically, Utah's Property Rights Ombudsman notes that HOAs generally cannot prohibit renting an internal ADU where it doesn't violate city code. However, detached ADUs and other configurations may still be subject to HOA restrictions in your CC&Rs. Always check your CC&Rs before starting any ADU project.