Iron County · 40,885 residents
Cedar City ADU rules
Cedar City: 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
Cedar City 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 | Cedar City's code sets no separate lot-size minimum for external ADUs beyond each zone's lot size (for example, 10,000 sq ft in R-1 and 7,000 sq ft in R-2), and from Oct 1, 2026 state law also guarantees the option on single-family lots of 11,000 sq ft or more. |
| Owner occupancy | City staff told the City Council in April 2026 that all internal and external ADUs must currently be owner-occupied. | City staff told the City Council in April 2026 that all internal and external ADUs must currently be owner-occupied. |
| Parking | One additional parking space is required, and any required spaces lost to the ADU must be replaced. | One space per ADU bedroom, and any required spaces lost to the ADU must be replaced; parking behind the home must be served by a driveway at least 12 ft wide and be behind the front setback. |
| Size limits | Not yet verified — confirm with the city | An external ADU may be no larger than 800 sq ft (1,200 sq ft in the R-E zone) with no more than two bedrooms. |
| Height | Not yet verified — confirm with the city | One story, no taller than 16 ft. |
| Setbacks | Not yet verified — confirm with the city | The unit must sit behind the main home and meet the main home's setbacks, not the smaller accessory-building setbacks (in R-1, for example, 8-ft minimum side yards totaling 20 ft and a 30-ft rear yard). |
| Zones | Permitted in the R-1 and R-E zones and, because those zones allow any R-1 use, in the single-family R-2 and R-3 zones; the ADU must have a separate address. | Permitted in the R-1 and R-E zones and, because those zones allow any R-1 use, in the single-family R-2 and R-3 zones; the ADU must have a separate address. |
| Permit process | A building permit is required to convert a basement or other space into an ADU. | A building permit is required; the unit must match the main home's color and roof design, meet current building and fire codes, and existing guest houses may be converted if they meet the same criteria. |
What the Cedar City council decided
Recorded votes and actions on ADU rules, linked to the public meeting record on OpenUtah.
· Planning Commission
Recommended approval of text amendments replacing specific state-code citations with general references and adding a definition for external ADUs.
Read the meeting record
Proposed or pending changes
Not adopted as of September 24, 2026. They do not change the rules above until the city adopts them.
- Apr 15, 2026: the City Council discussed a proposed new definition of external ADUs (borrowed from a failed 2026 state bill). Staff flagged two unintended effects: the new wording would drop owner occupancy for external ADUs and would bar external ADUs behind twin homes. The council discussed sending the definition back to the Planning Commission; the online code currently defines an external ADU as 'a unit as defined by the Utah Municipal Code which shall be detached from the primary structure.' Final outcome not confirmed.
State law: detached ADUs from October 1, 2026
Cedar City 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 Cedar City 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; Cedar City makes the decision.
- No numeric external minimum is recorded for Cedar City. 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 Cedar City 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 Cedar City before you apply.
- Cedar City Code Chapter 26, Article III — Zones (city PDF)
Official city copy (dated Nov 2022) listing internal and external ADUs as permitted uses in R-1 and R-E with size, bedroom, height, setback and parking-access standards; wording matches the current online code.
- Cedar City Building & Zoning FAQ
Confirms a building permit is needed to convert a basement into an ADU.
- Cedar City Council, Apr 15, 2026 — ADU definition discussion (OpenCity)
Staff explained current ADU rules (owner occupancy for all ADUs; twin homes) and a proposed new external-ADU definition.
- Cedar City Planning Commission, Mar 31, 2026 — code references and ADU definition (OpenCity)
PC recommended updating state-code references and clarifying the ADU definition.
- 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 Cedar City website
Common Cedar City ADU questions
Can you build an ADU in Cedar City?
Cedar City: internal ADUs allowed; detached ADUs allowed. Owner occupancy applies. This is planning guidance, not a permit. Confirm the zone on your parcel with Cedar City.
What lot size does Cedar City require for an ADU?
Internal ADU: Not yet verified — confirm with the city. Detached ADU: Cedar City's code sets no separate lot-size minimum for external ADUs beyond each zone's lot size (for example, 10,000 sq ft in R-1 and 7,000 sq ft in R-2), and from Oct 1, 2026 state law also guarantees the option on single-family lots of 11,000 sq ft or more.
Does Cedar City require the owner to live on the property?
Internal ADU: City staff told the City Council in April 2026 that all internal and external ADUs must currently be owner-occupied. Detached ADU: City staff told the City Council in April 2026 that all internal and external ADUs must currently be owner-occupied.
How much parking does a Cedar City ADU need?
Internal ADU: One additional parking space is required, and any required spaces lost to the ADU must be replaced. Detached ADU: One space per ADU bedroom, and any required spaces lost to the ADU must be replaced; parking behind the home must be served by a driveway at least 12 ft wide and be behind the front setback.
What does it cost to build an ADU in Cedar City?
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 Cedar City?
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 Cedar City 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 Cedar City lot?
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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.