Accessory Dwelling Units (ADUs)

When the Unified Development Code (UDC) went into effect on January 1, 2023, accessory dwelling units became eligible accessory uses in all residentially zoned districts. The requirements listed below will be applied to ADUs in the City. These requirements and additional requirements for ADUs come from Section 60.300.020G: Accessory Uses and Structures of the UDC.

• There shall be no more than one accessory dwelling unit on a lot
• An accessory dwelling unit must not contain more than 1,000 square feet of gross floor area.
• Detached accessory dwelling units shall only be located in the rear or side yard.
• The architectural style of the accessory dwelling unit, including but not limited to massing, roof shape, and exterior appearance shall be compatible with that of the principal dwelling unit on the lot.

The following document outlines the minimum code requirements applicable to a detached ADU. While not comprehensive, it serves to inform about some of the codes that must be adhered to.

The Accessory Dwelling Unit (ADU) Pilot Program supports property owners in the City of Rochester to develop ADUs on their properties. The program provides up to $20,000 in reimbursements for City fees and indirect costs associated with developing an ADU. All City fees, directly related to the development of the ADU (including pre-development costs), are eligible for reimbursement. An example of an indirect cost is the fee to restore a driveway or landscaping after installing a water service line to the ADU. The applicant will be required to provide documentation and rationale for any requests for the reimbursement of indirect costs.

At this time, the City has allocated $60,000 to the ADU Pilot Program. All fee reimbursements are subject to funding availability and are reviewed at the Rochester Community Development Department's discretion. A review of the pilot program's performance will be conducted once all program funding has been used, and a potential extension with additional funding will be considered. 

For more information, please contact Adam Froke.

Property Eligibility

The constructed ADU can be attached or detached to the existing structure(s) on the property. To be eligible for reimbursements in this program, the ADU must be located within the City Limits or Near Term Urban Expansion areas per the City of Rochester’s Growth Management Map.

Additionally, the constructed ADU will need to meet the standards outlined in the City of Rochester’s Unified Development Code (UDC) and adopted building codes.

Applicant Eligibility

Either the property owner or the person(s) occupying the ADU after construction need meet the following eligibility requirements:

• Gross Annual household income cannot exceed 80% of the Area Median Income (AMI) as determined by the US Department of Housing and Urban Development, Section 8 Program. Gross annual household income includes, but is not limited to, the following:
  • All income earned by the head of household, spouse, and other family members aged 18 years or older who reside at the residence.
  • Any other income source (child support, alimony, food stamps, etc.)
  • Income from Social Security, Pensions, Annuities, general relief, unemployment, and MFIP (Minnesota Families Investment Program).
  • Average net income for self-employed applicants is the average annual income from the previous two years, excluding depreciation, as reported in the tax return.
  • Income contributed or paid to the applicant on a regular basis by a person not living in the housing unit.
• Income not to be included in the renters’ gross household income tabulation includes:
  • Earned income of family members under 18 years of age.
  • The income of family members who are full-time students may or may not be counted as income, depending on HUD's income determination requirements.
• There is no asset limit in this program; income derived from assets will be considered towards the gross household income.

Fair Market Rents and Short-Term Rentals

 The following fair market rents (FMR) and short-term rental requirements will apply to ADUs funded through this pilot program. Should the property owner elect to live in the ADU and rent the primary dwelling on the property, the same requirements listed below will apply to the primary dwelling.

Applications

An application for the ADU Pilot Program should be completed and submitted after:

• fees for which reimbursements are being requested have been paid in full;
• construction on the ADU is complete; and
• A Certificate of Occupancy has been issued by City Staff.

For more information, including application instructions, contact Adam Froke.

The City of Rochester collaborated with the Coalition for Rochester Area Housing and Lake City to create a series of sample ADU designs. These designs are intended to streamline the city review process and serve as inspiration for residents looking to add an ADU to their properties. An initial cursory review has been conducted on these concept drawings for feasibility. However, City Staff will still need to complete a thorough individual review once full construction documents have been prepared as part of the project-specific submittal.

1. Detached ADUs: These are standalone structures that exist independently of the primary dwelling. Detached ADUs can be small cottages or converted garages.
   • Advantages: Offer privacy and a sense of separation from the main house. Provide flexibility in terms of design and use.
2. Attached ADUs: Attached ADUs are connected to the main house and may share walls or a common entryway. They are generally built as additions to the existing structure but can also be conversions of existing rooms.
   • Advantages: Convenient access to the main residence, making it suitable for families who want to stay close while having independent living spaces.
3. Interior ADUs: These ADUs are created by converting existing interior spaces within the main house, such as basements, attics, or unused rooms. They may have a separate entrance or share common areas with the main residence.
   • Advantages: Utilizes existing space efficiently and often involves lower construction costs compared to building a separate structure.

To build an ADU on your property, you will need to create a design concept for your project. Here are some questions you should consider when adding an ADU to your property: 

• Do I want the ADU to be attached or detached from the primary residence?
• What is my budget for building the ADU?
• Who will be living in the ADU once it’s completed?
• How large does the ADU need to be to meet the needs of future occupants?

Site Plan 

After answering these questions, you'll need to develop a site plan for the project.  The site plan should include:

• The location of the primary structure and ADU
• Gross square footage
• Setbacks
• Access points
• Other relevant information

The initial site plan you submit to City staff can be informal, but the final design and construction documents must be prepared by a licensed architect in the State of Minnesota.

Pre-Development Meeting

Once you have a site plan and a basic design concept prepared, it is recommended that you request a Pre-Development meeting with City staff.

• Meetings are held every Thursday afternoon, starting at 1 pm.
• Meetings provide City staff with an opportunity to advise applicants on procedural requirements for new development projects.
• During the meeting, project-related issues are discussed, and information is exchanged.
• You must submit the meeting request and any required documents by 5 pm on the Thursday of the week prior to the desired meeting.
• Please refrain from submitting a Pre-Development Meeting Request Form until you have, at a minimum, a site plan prepared to submit.
• Additional information on Pre-Development Meetings and the request form is available on the Planning & Zoning page.

The following document outlines the minimum code requirements applicable to a detached ADU. While not comprehensive, it serves to inform about some of the codes that must be adhered to.