Salt Lake County · 31,381 residents
Magna ADU rules
Magna: internal ADUs allowed (lot 6,000+ sq ft); detached ADUs allowed (lot 8,000+ sq ft). Owner occupancy applies.
Internal ADU (inside the home)
Detached ADU (backyard building)
✓ Checked against city sources on September 24, 2026 See sources
Magna 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. Internal and attached ADUs are allowed on lots of 6,000 sq ft or more in Magna's residential, agricultural and planned-community zones. | 8,000 sq ft. Detached ADUs are allowed on lots of 8,000 sq ft or more (6,000 sq ft in a planned-community zone with city-approved design standards). |
| Owner occupancy | The owner must live in the main home or the ADU; absences for medical, military or religious reasons of up to two years are allowed with an on-site manager. An owner-occupancy affidavit and a Notice of Accessory Dwelling Unit are recorded against the property, and a new owner must re-apply. | The owner must live in the main home or the ADU; absences for medical, military or religious reasons of up to two years are allowed with an on-site manager. An owner-occupancy affidavit and a Notice of Accessory Dwelling Unit are recorded against the property, and a new owner must re-apply. |
| Parking | One on-site parking space for the ADU in addition to the home's required parking; a converted garage's spaces must be replaced. | Two on-site parking spaces for a detached ADU in addition to the home's required parking; a converted garage's spaces must be replaced. Beginning Oct. 1, 2026, state law caps this at one space for a detached ADU under 650 sq ft. |
| Size limits | Not yet verified — confirm with the city | No fixed square-footage cap in the ADU section; the unit must stay within the zone's lot-coverage and rear-yard-coverage limits. |
| Height | Not yet verified — confirm with the city | A detached ADU may be no taller than the existing home. |
| Setbacks | Internal and attached ADUs follow the zone's normal setbacks for a single-family home. | New detached ADUs need at least 5 ft side and rear setbacks (or the utility-easement line if larger) and 6 ft from the main house; they cannot sit in a front or street-side yard and must be set back at least 10 ft behind the home's front facade. |
| Zones | Permitted use in Magna's R (residential), A (agricultural) and PC (planned community) zones; not allowed with townhomes, multifamily PUDs or other attached housing. | Permitted use in Magna's R, A and PC zones; not allowed with townhomes, multifamily PUDs or other attached housing. |
| Short-term rentals | ADUs may not be used as short-term rentals; rentals must be 30 consecutive days or more. | ADUs may not be used as short-term rentals; rentals must be 30 consecutive days or more. |
| Permit process | Requires a building permit through the Greater Salt Lake Municipal Services District and written confirmation from the water supplier; a business license is required before renting. | Requires a building permit through the Greater Salt Lake Municipal Services District and written confirmation from the water supplier; a business license is required before renting. |
What the Magna council decided
Recorded votes and actions on ADU rules, linked to the public meeting record on OpenUtah.
· Magna Metro Township Council
Approved Ord. 2024-O-03: detached ADU minimum lot reduced to 8,000+ sq ft; two parking spaces per detached ADU (unanimous)
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.
- No local SB284 amendment found in Magna Planning Commission or Council records through Sept. 2026. Magna's 8,000 sq ft detached-ADU threshold is already below the statewide 11,000 sq ft floor, but its two-space parking rule exceeds the state cap of one space for detached ADUs under 650 sq ft once Utah Code 10-21-304 takes effect Oct. 1, 2026.
State law: detached ADUs from October 1, 2026
Magna 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 Magna 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; Magna makes the decision.
- The statewide map screen starts a new external ADU at about 11,000 sq ft. Magna's researched external minimum is 8,000 sq ft. Lots below that city minimum stay highly unlikely on the map even when they clear 11,000 sq ft.
- "Likely" above 15,000 sq ft is this site's planning band for a large recorded lot. It is not a sentence in the Magna 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 Magna before you apply.
- Magna Metro Township Council minutes, Feb. 27, 2024 — Ordinance 2024-O-03 (detached ADU lot size and parking)
Council lowered the detached-ADU minimum lot from 12,000 to 8,000+ sq ft and required two parking spaces per detached ADU (unanimous).
- Magna — Building Permits and Inspections
Building permits and inspections are handled by the Greater Salt Lake Municipal Services District (MSD) via its online portal.
- Greater Salt Lake MSD — Magna City long-range planning
MSD provides planning services to Magna City.
- Utah S.B. 284 (2026) enrolled — Utah Code 10-21-304
Statewide detached-ADU rules effective Oct. 1, 2026, including parking caps.
- U.S. Census Bureau Vintage 2024 Utah city population estimates
2024 population 31,381 (listed as Magna metro township).
- Utah Code 10-2-301 — classification of municipalities
30,000-64,999 = third class.
- Official Magna website
Common Magna ADU questions
Can you build an ADU in Magna?
Magna: internal ADUs allowed (lot 6,000+ sq ft); detached ADUs allowed (lot 8,000+ sq ft). Owner occupancy applies. This is planning guidance, not a permit. Confirm the zone on your parcel with Magna.
What lot size does Magna require for an ADU?
Internal ADU: 6,000 sq ft minimum. Internal and attached ADUs are allowed on lots of 6,000 sq ft or more in Magna's residential, agricultural and planned-community zones. Detached ADU: 8,000 sq ft minimum. Detached ADUs are allowed on lots of 8,000 sq ft or more (6,000 sq ft in a planned-community zone with city-approved design standards).
Does Magna require the owner to live on the property?
Internal ADU: The owner must live in the main home or the ADU; absences for medical, military or religious reasons of up to two years are allowed with an on-site manager. An owner-occupancy affidavit and a Notice of Accessory Dwelling Unit are recorded against the property, and a new owner must re-apply. Detached ADU: The owner must live in the main home or the ADU; absences for medical, military or religious reasons of up to two years are allowed with an on-site manager. An owner-occupancy affidavit and a Notice of Accessory Dwelling Unit are recorded against the property, and a new owner must re-apply.
How much parking does a Magna ADU need?
Internal ADU: One on-site parking space for the ADU in addition to the home's required parking; a converted garage's spaces must be replaced. Detached ADU: Two on-site parking spaces for a detached ADU in addition to the home's required parking; a converted garage's spaces must be replaced. Beginning Oct. 1, 2026, state law caps this at one space for a detached ADU under 650 sq ft.
Can an ADU in Magna be a short-term rental?
Internal ADU: ADUs may not be used as short-term rentals; rentals must be 30 consecutive days or more. Detached ADU: ADUs may not be used as short-term rentals; rentals must be 30 consecutive days or more.
What does it cost to build an ADU in Magna?
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 Magna?
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 Magna 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 Magna 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.