Salt Lake County · 46,680 residents
Riverton ADU rules
Riverton: internal ADUs allowed; detached ADUs allowed. Owner occupancy applies.
Internal ADU (inside the home)
Detached ADU (backyard building)
✓ Checked against city sources on September 24, 2026 See sources
Riverton ADU rules at a glance
| Rule | Internal ADU (basement, attic, inside the home) | Detached ADU (backyard building) |
|---|---|---|
| Allowed? | Allowed | Allowed |
| Minimum lot | Riverton's ADU rules set no minimum lot size; the lot just has to meet the ADU chapter's technical requirements such as parking. | Riverton's ADU rules set no minimum lot size for a detached ADU; the unit must fit within the city's accessory-building limits, and from Oct 1, 2026 state law also guarantees the option on single-family lots of 11,000 sq ft or more. |
| Owner occupancy | An owner must live on the property, in either the main home or the ADU, and sign an owner-occupancy affidavit. | An owner must live on the property, in either the main home or the ADU, and sign an owner-occupancy affidavit. |
| Parking | At least one dedicated on-site parking space is required for the ADU. | At least one dedicated on-site parking space is required for the ADU. |
| Size limits | Not yet verified — confirm with the city | A detached ADU is limited by Riverton's accessory-building rules: no single accessory building larger than twice the footprint of the house (including attached garage), and all accessory buildings together no more than 10% of the lot area. |
| Height | Not yet verified — confirm with the city | Accessory buildings are limited to 20 ft (up to 25 ft on lots of at least 10,000 sq ft), and to one story on lots under one-third acre (14,000 sq ft). |
| Setbacks | Not yet verified — confirm with the city | Accessory-building setbacks apply: at least 10 ft from the house, 5 ft from side and rear lot lines (15 ft if over 20 ft tall or two stories), and not within the front yard or within 10 ft of the front plane of the house. |
| Zones | Allowed in all single-family zones. | Allowed in all single-family zones, in a new building or by converting an existing detached accessory building. |
| Permit process | A one-time Riverton ADU permit (registration) is required to rent the unit, with a $175 application fee, a pre-application conference, an owner-occupancy affidavit and any needed building permits; the ADU permit is not required when the space is rented to family members. | A one-time Riverton ADU permit (registration) is required to rent the unit, with a $175 application fee, a pre-application conference, an owner-occupancy affidavit, site plan and elevations, plus building permits; the ADU permit is not required when the space is rented to family members. |
Proposed or pending changes
Not adopted as of September 24, 2026. They do not change the rules above until the city adopts them.
- Sept 1, 2026: the City Council held a work-session discussion on whether to modernize Riverton's ADU ordinance (e.g., allowing more than one ADU on some lots, parking, and enforcement). Staff said the code currently allows one ADU per single-family lot. No amendment had been adopted as of this review (code history ends with Ord. 24-22).
State law: detached ADUs from October 1, 2026
Riverton 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 Riverton 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; Riverton makes the decision.
- No numeric external minimum is recorded for Riverton. The map keeps the statewide 11,000 sq ft external screen and shows the researched status (generally allowed) on the property report.
- "Likely" above 15,000 sq ft is this site's planning band for a large recorded lot. It is not a sentence in the Riverton 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.
Sources
We link only to government sources and public meeting records. Codes change; confirm the current version with Riverton before you apply.
- Riverton Planning FAQ — ADUs / renting a basement
Confirms ADUs allowed in all single-family zones (internal and detached) and the one-time ADU permit.
- Riverton ADU application and owner-occupancy affidavit
$175 application fee, pre-application conference, ADU types, owner-occupancy affidavit citing 18.225.080.
- Riverton Ordinance 24-22 (Chapter 18.225 Accessory Structures)
Current accessory-structure setbacks, size and height limits that apply to detached ADUs (adopted Nov 12, 2024).
- Riverton City Council, Sept 1, 2026 — ADU discussion (OpenCity)
Council work-session discussion of whether to modernize the ADU ordinance; no amendment adopted.
- Utah S.B. 284 (2026), enrolled copy
Enacts Utah Code 10-21-304 (effective Oct 1, 2026): specified municipalities must permit a detached ADU on single-family lots of 11,000 sq ft or more; defines 'specified municipality'.
- Utah Code 10-2-301 — Classification of municipalities
City class thresholds (third class = 30,000 to 64,999).
- Utah Code 17-60-104 — Classification of counties
County class thresholds (first class >= 1,150,000; third class 40,000 to 259,999).
- U.S. Census Bureau Vintage 2024 subcounty population estimates
July 1, 2024 population estimates for Utah places.
- Official Riverton website
Common Riverton ADU questions
Can you build an ADU in Riverton?
Riverton: internal ADUs allowed; detached ADUs allowed. Owner occupancy applies. This is planning guidance, not a permit. Confirm the zone on your parcel with Riverton.
What lot size does Riverton require for an ADU?
Internal ADU: Riverton's ADU rules set no minimum lot size; the lot just has to meet the ADU chapter's technical requirements such as parking. Detached ADU: Riverton's ADU rules set no minimum lot size for a detached ADU; the unit must fit within the city's accessory-building limits, and from Oct 1, 2026 state law also guarantees the option on single-family lots of 11,000 sq ft or more.
Does Riverton require the owner to live on the property?
Internal ADU: An owner must live on the property, in either the main home or the ADU, and sign an owner-occupancy affidavit. Detached ADU: An owner must live on the property, in either the main home or the ADU, and sign an owner-occupancy affidavit.
How much parking does a Riverton ADU need?
Internal ADU: At least one dedicated on-site parking space is required for the ADU. Detached ADU: At least one dedicated on-site parking space is required for the ADU.
What does it cost to build an ADU in Riverton?
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 Riverton?
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 Riverton 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 Riverton 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: U.S. Census Bureau population estimate (2024). Editorial standards.