Davis County · 33,252 residents
Kaysville ADU rules
Kaysville: internal ADUs allowed (lot 6,000+ sq ft); detached ADUs allowed (lot 11,000+ sq ft). Owner occupancy applies.
Internal ADU (inside the home)
Detached ADU (backyard building)
✓ Checked against city sources on September 24, 2026 See sources
Kaysville ADU rules at a glance
| Rule | Internal ADU (basement, attic, inside the home) | Detached ADU (backyard building) |
|---|---|---|
| Allowed? | Allowed | Allowed |
| Minimum lot | 6,000 sq ft. The lot must be larger than 6,000 sq ft. | 11,000 sq ft. Detached ADUs are allowed on lots of 11,000 sq ft or more with a single-family detached home, matching the statewide floor. |
| Owner occupancy | The owner must live in either the main home or the ADU as their primary residence and submit an owner-occupancy affidavit. | The owner must live in either the main home or the ADU as their primary residence and submit an owner-occupancy affidavit. |
| Parking | At least one off-street space, paved with asphalt or concrete and not tandem with the home's required parking; any garage or carport spaces lost to the ADU must be replaced. | One off-street space for a unit of 650 sq ft or less, or two for a larger unit; spaces must be paved and not tandem with the home's parking. |
| Size limits | Not yet verified — confirm with the city | No larger than 50% of the main home's footprint (including the garage) or 1,200 sq ft, whichever is smaller; for a loft over a garage, only the living area counts. |
| Height | Not yet verified — confirm with the city | No taller than the main home, with a 25 ft maximum. |
| Setbacks | Not yet verified — confirm with the city | A one-story unit must meet the same side and rear setbacks as a house in the zone. A two-story unit's side setback increases to match the zone's rear setback. Not allowed in the front yard or any recorded or utility easement. Second-story decks and balconies must meet the unit's setbacks, and the council added a limit on where they can face (final wording not yet published). |
| Zones | Allowed with a legal, conforming single-family detached home in all primarily residential zones; one ADU per lot, no separate utility meters, and not on a property with a failing septic tank. | Allowed with a legal, conforming single-family detached home in all primarily residential zones on lots of 11,000 sq ft or more; one ADU per lot. |
| Short-term rentals | An internal ADU cannot be rented for less than 30 consecutive days. | A detached ADU cannot be rented for less than 90 consecutive days. |
| Permit process | An ADU permit and a city rental license are required before renting, along with a building permit for any addition or remodel; the home must keep its single-family appearance. | An ADU permit plus a rental license, and a building permit. The design must be consistent with the house. No separate utility meters, and not where utility capacity is insufficient. RVs, trailers and mobile homes can't be used. Existing legal accessory buildings can be converted only if they meet these standards. |
What the Kaysville council decided
Recorded votes and actions on ADU rules, linked to the public meeting record on OpenUtah.
· Kaysville City Council · Approved
City Council approved an ordinance amending 17-31-3 to regulate internal and detached ADUs to comply with SB 284, with changes discussed; vote from transcript.
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.
- The Sept 17, 2026 approval included changes discussed at the meeting. Second-story DADU decks and balconies would have to be on a facade facing an interior yard and cover no more than half its width, measured from the interior corner. The final signed ordinance with this wording had not been posted on the state notice site as of Sept 24, 2026.
State law: detached ADUs from October 1, 2026
Kaysville 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 Kaysville 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; Kaysville 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 Kaysville 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 Kaysville before you apply.
- Kaysville City Council, Sept 17, 2026 packet — draft ordinance repealing and readopting KCC 17-31-3 (Accessory Dwelling Units)
Staff report and full ordinance text for general, IADU and DADU standards (pages 59-64).
- Kaysville City Council, Sept 17, 2026 — ADU ordinance approval (OpenCity)
Transcript: staff presentation, council direction to limit second-story decks and balconies, and approval 'with the changes ... discussed' (motion carries).
- Kaysville — Internal Accessory Dwelling Units page
City IADU page: permit if occupied by non-family, building permit for alterations (predates the Sept 2026 amendment).
- 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 population thresholds.
- Utah Code 17-60-104 — Classification of counties
County class population thresholds.
- U.S. Census Bureau Vintage 2024 subcounty population estimates
July 1, 2024 population estimates for Utah places and counties.
- Official Kaysville website
Common Kaysville ADU questions
Can you build an ADU in Kaysville?
Kaysville: internal ADUs allowed (lot 6,000+ sq ft); 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 Kaysville.
What lot size does Kaysville require for an ADU?
Internal ADU: 6,000 sq ft minimum. The lot must be larger than 6,000 sq ft. Detached ADU: 11,000 sq ft minimum. Detached ADUs are allowed on lots of 11,000 sq ft or more with a single-family detached home, matching the statewide floor.
Does Kaysville require the owner to live on the property?
Internal ADU: The owner must live in either the main home or the ADU as their primary residence and submit an owner-occupancy affidavit. Detached ADU: The owner must live in either the main home or the ADU as their primary residence and submit an owner-occupancy affidavit.
How much parking does a Kaysville ADU need?
Internal ADU: At least one off-street space, paved with asphalt or concrete and not tandem with the home's required parking; any garage or carport spaces lost to the ADU must be replaced. Detached ADU: One off-street space for a unit of 650 sq ft or less, or two for a larger unit; spaces must be paved and not tandem with the home's parking.
Can an ADU in Kaysville be a short-term rental?
Internal ADU: An internal ADU cannot be rented for less than 30 consecutive days. Detached ADU: A detached ADU cannot be rented for less than 90 consecutive days.
What does it cost to build an ADU in Kaysville?
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 Kaysville?
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 Kaysville 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 Kaysville 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.