Salt Lake County · 30,588 residents
Holladay ADU rules
Holladay: 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
Holladay 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 | Holladay's current code does not set a separate minimum lot size for a detached ADU; the unit must instead fit the city's accessory-building footprint, setback and lot-coverage limits. |
| Owner occupancy | The owner, or an immediate family member (spouse, parent, child, sibling, grandparent or grandchild), must live full time in the main home or the ADU; temporary absences of up to three years for military service, job assignment, sabbatical or voluntary service are excepted. | The owner, or an immediate family member (spouse, parent, child, sibling, grandparent or grandchild), must live full time in the main home or the ADU; temporary absences of up to three years for military service, job assignment, sabbatical or voluntary service are excepted. |
| Parking | Provide one additional on-site parking stall beyond the home's normal requirement, and replace any garage or carport spaces lost to the conversion. | When the ADU is built outside the existing home's footprint, on-site parking must meet the city's standard minimums based on the number of bedrooms in the ADU; parking reductions may be available. |
| Size limits | Not yet verified — confirm with the city | Minimum footprint of 200 sq ft; maximum footprint follows the city's accessory-building chart, which scales with lot size (800 sq ft on lots under 8,000 sq ft up to 1,400 sq ft on lots over 80,600 sq ft), and lot-coverage maximums also apply. |
| Height | Not yet verified — confirm with the city | Up to 25 ft above existing grade, subject to the city's graduated-height rules. |
| Setbacks | Not yet verified — confirm with the city | Must meet accessory-building setbacks for the zone; setbacks can be reduced for measures such as single-story design, masonry walls or below-grade space, but never closer than the chart's minimum distance (3 to 15 ft depending on lot size). |
| Zones | Allowed in all residential zones on a parcel with a detached single-family home. | Allowed in all residential zones on a parcel with a detached single-family home. |
| Short-term rentals | If rented, the ADU must be rented for at least 30 consecutive days. | If rented, the ADU must be rented for at least 30 consecutive days. |
| Permit process | Requires a building permit and certificate of occupancy; renting the ADU requires an annual city license. | Requires a building permit and certificate of occupancy; converting an oversized existing accessory building can require a conditional use permit; renting requires an annual city license. |
What the Holladay council decided
Recorded votes and actions on ADU rules, linked to the public meeting record on OpenUtah.
· City Council
Adopted Ord. 2024-18 rewriting §13.14.031 ADU standards (removed the prior lot-size threshold for external ADUs, added setback-reduction chart, conversion rules and 25-ft height)
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.
- Sept. 15 and Sept. 22, 2026: Planning Commission public hearing on SB284 ADU amendments (File 24-4-02-1). Proposed changes: detached ADU parking of two spaces for units 650 sq ft or larger and one space for smaller units, revised design standards, and explicit detached-ADU allowance in R-2 and R-M zones. Requires City Council adoption; not yet adopted as of 2026-09-24.
State law: detached ADUs from October 1, 2026
Holladay 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 Holladay 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; Holladay makes the decision.
- No numeric external minimum is recorded for Holladay. 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 Holladay 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 Holladay before you apply.
- Holladay Planning Commission packet, Sept. 15, 2026 — SB284 ADU amendments (includes current §13.14.031 text)
Current ADU standards (Ord. 2024-18) shown with proposed SB284 edits; establishes zones, owner occupancy, 30-day rentals, footprint, 25-ft height.
- Holladay Planning Commission, Sept. 22, 2026 — SB284 ADU ordinance amendment hearing
Pending amendment to align ADU parking, design and approval process with Utah Code 10-21-304.
- Utah S.B. 284 (2026) enrolled — Utah Code 10-21-304
Statewide detached-ADU rules effective Oct. 1, 2026; parking caps.
- U.S. Census Bureau Vintage 2024 Utah city population estimates
2024 population 30,588.
- Utah Code 10-2-301 — classification of municipalities
30,000-64,999 = third class.
- Official Holladay website
Common Holladay ADU questions
Can you build an ADU in Holladay?
Holladay: internal ADUs allowed; detached ADUs allowed. Owner occupancy applies. This is planning guidance, not a permit. Confirm the zone on your parcel with Holladay.
What lot size does Holladay require for an ADU?
Internal ADU: Not yet verified — confirm with the city. Detached ADU: Holladay's current code does not set a separate minimum lot size for a detached ADU; the unit must instead fit the city's accessory-building footprint, setback and lot-coverage limits.
Does Holladay require the owner to live on the property?
Internal ADU: The owner, or an immediate family member (spouse, parent, child, sibling, grandparent or grandchild), must live full time in the main home or the ADU; temporary absences of up to three years for military service, job assignment, sabbatical or voluntary service are excepted. Detached ADU: The owner, or an immediate family member (spouse, parent, child, sibling, grandparent or grandchild), must live full time in the main home or the ADU; temporary absences of up to three years for military service, job assignment, sabbatical or voluntary service are excepted.
How much parking does a Holladay ADU need?
Internal ADU: Provide one additional on-site parking stall beyond the home's normal requirement, and replace any garage or carport spaces lost to the conversion. Detached ADU: When the ADU is built outside the existing home's footprint, on-site parking must meet the city's standard minimums based on the number of bedrooms in the ADU; parking reductions may be available.
Can an ADU in Holladay be a short-term rental?
Internal ADU: If rented, the ADU must be rented for at least 30 consecutive days. Detached ADU: If rented, the ADU must be rented for at least 30 consecutive days.
What does it cost to build an ADU in Holladay?
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 Holladay?
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 Holladay 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
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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.