What You’re Allowed to Build in
County of Salt Lake ADU Local Zoning Laws
KEY RULES AT A GLIMPSE
Size and Separation
Maximum size: 1200 sqft
Side/rear setbacks: 4 feet
Two story: Yes
Building separation: 6 feet
Additional Requirements
Soils Report: No
Building Verification Survey: No
Coastal permit (in some areas): No
Stormwater Mitigation: No
Regulations for Accessory Dwelling Units
Permission for Internal Accessory Dwelling Unit
Yes
Lot Coverage
Lot coverage maximums as outlined per each zone.
Height Requirements
Height restrictions for IADUs: Must align with the height standards for single-family dwellings in the zone.
Detached ADUs with rear or side yard setback of less than ten feet: Maximum height is 20 feet.
Detached ADUs with rear or side yard setback of ten feet or more: Maximum height can match the height of the primary dwelling.
Parking Regulations
Property owners must provide at least one on-site parking space for the ADU, in addition to the required parking for the existing home.
The property owner must prove, by a preponderance of the evidence, that sufficient parking is available.
For garage conversions to create an IADU or detached ADU, any parking spaces previously required for the primary dwelling must be replaced.
Owner Occupancy
The principal unit or the ADU must have owner occupancy, except for medical, military service, or religious reasons for a time period of up to two years.
If an absence is warranted due to the above reasons, an on-site manager shall be designated.
The property owner may not receive rent for the unit that was occupied by the owner.
An application for an ADU shall include evidence of owner occupancy.
Additional Notes
Accessory buildings can only be built on a lot after the principal building is erected, unless both are constructed at the same time.
No more than one ADU, whether internal or detached, is permitted per lot.
Units approved as ADUs shall not be used as short-term rentals. Any rentals shall be made for thirty consecutive days or more.
An approved building permit is required for all ADUs before construction; non-compliant ADUs must obtain a permit and verify compliance with the code.
A building permit will not be issued until written confirmation from the water supplier confirms compliance with all applicable water service requirements.
ADU design and size must conform to all applicable building, fire, health, and water service codes. Detached ADUs must also meet these standards and obtain a building permit.
Detached ADUs must be built on a permanent concrete slab, except when constructed above a garage. No basements, piers, temporary, or wheeled structures are allowed.
Conversions must comply with safety requirements, including egress windows, window wells, and sufficient HVAC and climate control.
IADUs do not require a separate HVAC system or firewall.
The owner must provide a separate address for emergency and mailing services.
Detached ADUs are not allowed in the front or corner lot side yard unless the lot is at least one acre and the ADU is 30 feet from the front lot line.
New detached ADUs must be offset by 10 feet or more from the front facade of the main dwelling.
Detached ADUs must have adequate facilities for roof and other drainage.
Residences with a detached ADU must retain the appearance of a single-family home.
Applicants must provide an affidavit stating that the property owner will live in either the primary dwelling or the ADU as their permanent residence.
After ADU approval and issuance of a business license, a notice of accessory dwelling unit, including the affidavit, must be recorded against the property.
The recorded notice serves to inform future property owners of the owner occupancy requirement for the ADU.
Upon sale, the new owner must sign and record a new affidavit and obtain reauthorization of the ADU from the building and business license officials.
A copy of the recorded notice must be provided to the applicant once the recording process is completed.
ADUs are part of a single-family residence and shall not be used as a multi-family residence.
ADUs may not be separately metered apart from the single-family residence.
Applications for ADUs must include submittal of written verification from water and sewer providers that water and sewer are available to the ADU
ADUs may not be sold or subdivided separately from the single-family residence.
Municipal Department Contact Details
| Contact Information | |
| Contact Type | Phone Number |
| Main Phone | 385-468-7000 |
| Planning/Building Office Phone | 385-468-6700 |
The Zoning and Lot area Requirements for IADUs and Detached ADUs
| ADU Type | Permitted Zones | Minimum Lot Area | Additional Conditions |
| IADUs | R Zones, A Zones, Forestry Zones, PC Zone | 6,000 square feet or greater | Permitted use on single-family home lots in areas zoned primarily for residential use. |
| Detached ADUs | R Zones, A Zones, Forestry Zones | 7,000 square feet or greater | Detached ADUs are allowed on single-family home lots with the required lot area. |
| Detached ADUs (PC Zone) | PC Zone | 6,000 square feet or greater | Permitted if the county has approved design standards for the detached ADU. |
| Reference | https://library.municode.com/ut/salt_lake_county/codes/code_of_ordinances?nodeId=TIT19ZO_CH19.15ACDWUN_19.15.030ALARZO | ||
The Setback Requirements for Different Types of ADUs
| ADU Type | Setback Requirements |
| Internal ADUs (IADUs) | Setbacks are the same as those for a single-family dwelling in the zone. |
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Detached ADUs (Built After Adoption)
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– Side yard setbacks are consistent with those for a single-family dwelling in the zone. |
| – Rear yard setbacks are a minimum of ten feet. | |
| – Must be at least six feet from the main dwelling. | |
| – If existing PUEs are greater than the required setback, the minimum setback will be the PUE boundary. | |
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Conversion of Existing Accessory Structures
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– Side and rear yard setbacks must comply with the accessory structure setback standards that were in place when the structure was legally erected. |
| – The detached ADU must be at least six feet from the primary dwelling. | |
| – Exceptions are allowed for structures declared noncomplying under section 19.88.150. | |
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Reference
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Height and Area Regulations of Zoning Districts
R zones (R-1-3 to R-1-7)
| Standards | R-1-3 | R-1-4 | R-1-5 | R-1-6 | R-1-7 |
| Minimum Lot Area | 3,000 sq ft | 4,000 sq ft | 5,000 sq ft | 6,000 sq ft | 7,000 sq ft |
| Front Yard | 20 feet | 20 feet | 20 feet | 25 feet | 25 feet |
| Side Yard (Interior) | 5 feet | 5 feet | 5 feet | 5 feet on one side & 11 feet on the garage or driveway side | 5 feet on one side & 11 feet on the garage or driveway side |
| Side Yard (Facing a Public Street) | 20 feet | 20 feet | 20 feet | 20 feet | 20 feet |
| Rear Yard Without Garage | 20 feet | 20 feet | 20 feet | 30 feet | 30 feet |
| Rear Yard With Garage | 15 feet | 15 feet | 15 feet | 15 feet | 15 feet |
| Building Height (ft) | 30 | 30 | 30 | 30 | 30 |
R zones (R-1-8 to R-1-43)
| Standards | R-1-8 | R-1-10 | R-1-15 | R-1-21 | R-1-43 |
| Minimum Lot Area | 8,000 sq ft | 10,000 sq ft | 15,000 sq ft | 21,780 sq ft | 43,560 sq ft |
| Front Yard | 25 feet | 30 feet | 30 feet | 30 feet | 30 feet |
| Side Yard (Interior) | 5 feet on one side & 11 feet on the garage or driveway side | 10 feet | 10 feet | 10 feet | 15 feet |
| Side Yard (Facing a Public Street) | 20 feet | 20 feet | 20 feet | 20 feet | 20 feet |
| Rear Yard Without Garage | 30 feet | 30 feet | 30 feet | 30 feet | 30 feet |
| Rear Yard With Garage | 15 feet | 15 feet | 15 feet | 15 feet | 15 feet |
| Building Height (ft) | 30 | 30 | 30 | 30 | 30 |
A-Zones
| Standards | A-1 | A-2 | A-5 | A-10 | A-20 |
| Minimum Lot Area | 10,000 sq ft | 1 acre | 5 acres | 10 acres | 20 acres |
| Front Yard | 30 feet | 30 feet | 50 feet | 50 feet | 50 feet |
| Side Yard (Interior) | 8 feet on one side & 6 feet on the garage or driveway side | 10 feet | 20 feet | 20 feet | 20 feet |
| Side Yard (Facing a Public Street) | N/A | 20 feet | 50 feet | 50 feet | 50 feet |
| Rear Yard Without Garage | 30 feet |
30 feet
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50 feet
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50 feet
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50 feet
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| Rear Yard With Garage | N/A | ||||
| Building Height (ft) | 35 | N/A | 35 | 35 | 35 |
FR-Zones
| Standards | FR-0.5 | FR-1 | FR-2.5 | FR-5 | FR-10 | FR-20 | FR-50 | FR-100 |
| Minimum Lot Area | ½ acre | 1 acre | 2—2½ acres | 5 acres | 10 acres | 20 acres | 50 acres | 100 acres |
| Front Yard |
Limits of disturbance and setbacks in FR zones are determined case-by-case by the development services director for permitted uses, and by the planning commission for conditional uses, following the foothills and canyons overlay zone criteria.
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| Side Yard (Interior) | ||||||||
| Side Yard (Facing a Public Street) | ||||||||
| Rear Yard Without Garage | ||||||||
| Rear Yard With Garage | ||||||||
| Building Height (ft) | 35 | 35 | 35 | 35 | 35 | 35 | 35 | 35 |
Application Process for Building Permit
General Requirements
| General Requirements | ||
| Process | Requirements | Details |
| Street Address and Project Name | Specify the street address and project name on every sheet of plans | The address and project name must match the Certified Address |
| Plan Sets | Submit complete plans and supporting documents electronically | Use the CityWorks online portal; all plans must be drawn to scale |
| Plan Components | Include civil, site, architectural, structural, electrical, mechanical, and plumbing plans | Plans must be detailed and comprehensive, covering all aspects of the project |
| Soil Reports | Required for new residential buildings with a specific size | Applies to buildings with a footprint > 3,000 sq. ft. or total sq. ft. > 6,000 sq. ft |
| Code Analysis | Follow current codes adopted by MSD | Includes 2021 IRC with State amendments, 2021 International Codes, 2020 NEC, and ANSI A117.1-2009 |
| Sheet Index | Provide an index of all sheets in the submitted plans | Sheets must be listed in the correct order as attached to the full set |
| Site Plan | Provide a fully dimensional site plan drawn to scale | Not required for interior remodels that don’t increase parking or landscape requirements |
Architectural Requirements
| Architectural Requirements | ||
| Process | Requirements | Details |
| Plans | Provide foundation, floor, and roof plans drawn to scale | Clearly indicate existing versus new construction areas |
| Details/Sections | Provide construction details showing compliance with codes | Include details for all openings and penetrations in corridors or ceilings |
| Elevations | Provide interior and exterior building elevations | Elevations must be drawn to scale and fully dimensional |
| Schedules | Provide schedules for windows, doors, and window wells | Schedules should be detailed and comprehensive, reflecting all components of the project |
Structural Requirements
| Structural Requirements | ||
| Process | Requirements | Details |
| Special Inspections | Indicate portions of the work requiring Special Inspection per code | Complete and return a Special Inspection form before a permit is issued |
| Structural Analysis | Provide structural analysis, design, and detail per code | Must include calculations for wind loading, seismic, snow, and exposure per code |
Electrical Requirements
| Electrical Requirements | ||
| Process | Requirements | Details |
| Plans & Schedules | Provide complete electrical plans and schedules with load calculations | Indicate the number/replacement of fixtures that exist and are proposed |
| One Line Diagram | Provide a one-line electrical diagram with fault current calculations | Ensure grounding and all necessary electrical details are included |
Mechanical Requirements
| Mechanical Requirements | ||
| Process | Requirements | Details |
| Plans & Schedules | Provide complete mechanical plans and equipment schedules | Include equipment specifications, operating weight, and number/placement of fixtures |
Plumbing Requirements
| Plumbing Requirements | ||
| Process | Requirements | Details |
| Plans | Provide complete plumbing plans showing water, waste, vent, and fuel gas designs | All aspects of the plumbing system must be detailed |
| Fixture Schedules | Provide a complete list of plumbing fixtures and their associated units | Indicate the number/placement of existing and proposed plumbing fixtures |
Gas Approvals
| Gas Approvals | ||
| Process | Requirements | Details |
| Gas Line Diagram | Provide dimensions of each section and meter size for gas lines | Must include all relevant details for gas line design and installation |
| Gas Appliances | List all gas appliances, including BTU and OFH | Ensure all gas appliances and their specifications are documented |
Fees
| Fees | ||
| Process | Requirements | Details |
| Electrical | Indicate if the permit includes revisions to the existing electrical system or components | If it’s new construction, provide square footage. For remodels or additions, note the changes |
| Plumbing | Indicate if the submission includes replacement of existing plumbing or addition of new plumbing fixtures | Provide detailed information about any changes or additions to the plumbing system |
| Mechanical | Indicate if the submission includes replacement of existing HVAC or addition of new HVAC | Ensure all details about HVAC system changes or additions are included |
Fees for Building Permit and Application Process
| Process | Permit | Fees |
| New Construction | Building Permit | Varies based on valuation schedules |
| Addition or Remodel | Building Permit | Varies based on valuation schedules |
| System Inspection | Mechanical, Plumbing & Electrical Permit | $70.00 |
| Additional Fixtures | Fee per Additional Appliance or Fixture | $20.00 per unit |
| Grading Work | Grading Permit | Varies based on cubic yards |
| Retaining Wall Construction | Retaining Wall Permit | Varies based on project size |
| Demolition Work | Demolition Permit | Varies based on declared valuation |
| Residential Window/Door Replacement | Window & Door Replacement Permit – Residential | $70.00 |
| Residential Reroofing with Sheathing | Reroofing Permit – Residential with Sheathing | $125.00 |
| Residential Reroofing without Sheathing | Reroofing Permit – Residential without Sheathing | $75.00 |
| Small Solar Installation | Solar Power System Permit – Residential/Small Commercial (up to 20 kW) | $100.00 base fee + $30.00 per kW |
| Battery Storage | Battery Storage System | $2.00 per battery |
| Reinspection | Reinspection Fee | $50.00 |
| Pre-inspection After Disaster | Pre-inspection Fee | $70.00 |
| Multi-unit Inspection | Multi-unit Inspection Fee | $100.00 |
| After-hours Inspection | Overtime/After-hours Inspection Fee | $120.00 |
| Permit Cancellation | Cancellation of Building Permit | 25% of permit fee ($200 max) |
| Permit Reinstatement | Reinstatement Fee – General | 50% of permit fee |
| Final Inspection Reinstatement | Reinstatement Fee – Final Inspection | 50% of permit fee ($200 max) |
| Work Without Permit | Building Without a Permit | 200% of permit fee, plus 1% per day |
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Reference
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