Roseville, MN Accessory Structures: ADU Rules (2026)

Section 1011.12(b)(1) of the Roseville City Code sets the standards for accessory dwelling units. An ADU must be located on a lot occupied by a one-family dwelling, and no more than one ADU is allowed on a lot. A detached ADU can be located above a detached garage or within a separate accessory building that meets the accessory building standards of section 1004.02, which makes a garage apartment a legal form.

Size is capped on both ends. An ADU must include at least 300 square feet of living area up to a maximum of 650 square feet, and in no case can it exceed 75 percent of the principal dwelling's four season living area, exclusive of the ADU. Living area includes kitchen areas, bathrooms, living rooms, bedrooms (including the closet which defines the bedroom), and other rooms, and excludes utility rooms, hallways, entryways, storage areas, and garages. An ADU includes a maximum of one bedroom. Height cannot exceed the standards for principal or accessory buildings, as applicable, and ADUs meet the setback standards for principal buildings.

Other requirements add to the list. The property needs at least one additional, conforming, off-street parking space beyond what the principal dwelling requires. The ADU gets its own address identifier: Unit A for an attached ADU and Unit B for a detached ADU, following the primary property address. A detached ADU entryway connects to a street frontage with a paved walkway, and its exterior finish material, roof pitch, trim, eaves, and window proportions must match the principal dwelling. An attached ADU cannot significantly alter the principal building so that it no longer looks like a one-family dwelling. Home occupations are permitted in ADUs within the combined limits in subsection (b)(3).

Renting an ADU needs a separate occupancy permit from the Community Development Department; Appendix A lists the Accessory Dwelling Unit permit under section 1011.12.B at $110.00.