Millcreek ADU Permits: Steps, Documents and Fees

This page covers the process. For what the rules allow (lot size, size limits, setbacks, parking and design), see Millcreek ADU rules. For how those rules play out on a real lot, see building an ADU in Millcreek.

The city's ADU page puts it plainly: an ADU application must be completed with Planning & Zoning before a building permit can be applied for. Every ADU, internal, attached or detached, goes through both stages.

Before you apply

Three checks save the most time. First, confirm the zone. Attached and detached ADUs are clearly permitted in the R-1 and A zones, and a July 2026 amendment broadened eligibility language, but parts of the chapter still name only those zones, so properties elsewhere should confirm with Planning. Second, confirm owner occupancy and gather proof now (see below). Third, the Building Department asks anyone adding a new building or square footage to contact the utility companies and confirm service can be provided. Our feasibility review covers all three.

Stage 1: the Planning & Zoning ADU application

The application is uploaded through Millcreek's planning portal (iWorQ). The city's ADU page lists these documents:

• Letter of Intent
• ADU Checklist
• Property Owner Affidavit (notarized)
• Site Plan
• Building Elevations with Dimensions (attached and detached ADUs)
• Floor Plan

The ADU Checklist adds a completed Land Use Application, the application fee, a description of the main dwelling, statements that the property contains an ADU and is owner-occupied and that the ADU may only be used as the city's rules allow, and elevations, floor plans and a site plan drawn to scale. A new detached ADU also needs a complete Site Plan Review application.

Once Planning reviews the application for completeness, it emails next steps, an ADU Affidavit and the applicable fees.

How the city decides

In the code, the approval is a Compliance Determination decided by the Planning Director. The listed steps are application submittal, completeness review, compliance review, and a decision with findings. No public hearing is listed. On approval, a notice of compliance is recorded at the Salt Lake County Recorder's Office stating that the property contains an ADU and is owner-occupied. The approval lapses if the home stops being owner-occupied.

Proving owner occupancy

The code asks for:

• a current-year Salt Lake County property tax notice, or a closing statement from the last calendar year, showing fee title held by an individual or by a trustor of a trust with at least a 50 percent ownership interest;
• a government ID showing the property address; and
• documents from at least two listed categories, such as vehicle registration, voter registration, or a W-2 or 1099.

See ADU owner occupancy for how other cities handle this.

Stage 2: the building permit

After Planning approval, the building permit is submitted through the Building Department's separate iWorQ portal, with all documents in PDF: existing and proposed plans, an Owner/Builder Form or Contractor Information Sheet, and the matching requirement list. The city publishes lists for 1 and 2 family dwellings, residential additions, residential alterations and accessory structures; which one fits a given ADU is worth confirming with the Building Department. The project is reviewed by a city engineer, a planner and the Fire Marshal.

Millcreek's building page lists the 2021 International Residential Code among its adopted codes, and state law continues to adopt the 2021 IRC for homes (Utah Code 15A-2-103). See ADU building code.

Published building permit timing

These are the city's estimates, not deadlines. The Planning stage has no published review time.

Who can pull the permit

The Building Department's FAQ says owners doing their own work on their personal residence do not need a general contractor, but homes under LLC ownership and rental properties require one.

Fees (FY26 schedule)

From Millcreek's Consolidated Fee Schedule, linked from the Building Department as the FY26 schedule, with pages dated November 12, 2025:

The schedule has two site plan approval lines, $800.00 outside Sensitive Lands and $1,600.00 within them, and a separate $100 accessory building line that excludes ADUs. Which line a detached ADU pays is our reading, so confirm it with Planning. We did not find an FY27 schedule; fees may have changed after July 1, 2026. Utility provider fees are separate.

After construction: renting the ADU

Anyone renting an ADU in Millcreek needs a Millcreek business license; the city code counts the rental of residential dwellings as a business. The long-term rental license asks for a site plan showing the rental square footage and parking, a Rental Inspection Checklist, a notarized Property Owner Authorization Form if the applicant is not the owner, and name verification for a DBA or LLC. A detached ADU cannot be a short-term rental.

Extra steps in hazard areas

• Sensitive Lands: building permits that add square footage in a Sensitive Lands Area need a geotechnical report.
• Wildland-Urban Interface: since January 1, 2026, Millcreek administers the WUI code, with a city map and a Fire Hazard Severity Form.
• Floodplain: the Building Department flags special requirements in the Neff's Creek floodplain.

Contacts

Planning & Zoning: planner@millcreekut.gov, 801-214-2700. Building Department: buildingservices@millcreekut.gov, 801-214-2749. City Hall is at 1330 East Chambers Avenue.

How we handle the paperwork

We prepare the Planning application and drawings, coordinate engineering and the building permit submittal, and respond to review comments, keeping the owner-occupancy documents and affidavits in order. We cannot promise an approval or a date; our aim is applications that go in complete. ADU permitting explains our role, and the ADU permit process covers the general Utah sequence. When you are ready, See What Your Property Can Support.

Questions about Millcreek ADU permits