Inver Grove Heights is considering joining other Twin Cities suburbs in allowing "granny flats" in single-family neighborhoods under certain conditions.

"Granny flats," formally called accessory dwelling units, are second residences that homeowners can create as an addition to their houses or in a garage or other structure on their property. They typically enable seniors to live near family members but also can provide affordable housing to young singles and families.

In Dakota County, cities that allow them include Eagan, Apple Valley, Lake- ville and Farmington, according to Inver Grove Heights planning officials.

Inver Grove Heights' zoning code now allows only one dwelling unit — defined as living, bath and sleeping spaces and a kitchen — per lot in single-family areas. Residents can add living, bath and sleeping spaces to single-family homes but not a second kitchen, because that would constitute a second dwelling unit.

An amendment to the city's zoning code that would let single-family homeowners add a second, accessory dwelling unit received unanimous City Council approval on Monday. A third and final vote could take place at the council's next meeting, on Aug. 24, if city staff completes research on council questions regarding possible rental of accessory dwelling units and occupancy by nonfamily members.

Citywide approach

The council is taking a citywide approach to regulating granny flats in response to a request from a resident. He and his wife want to convert the second floor of a detached, unused garage on their 2.7-acre property into a full living space for their daughter and son-in-law. The couple moved into his basement a couple of years ago, and the resident explained that he and his wife wanted to help them, while the younger couple would help them stay in their house longer.

The amendment would allow detached accessory dwelling units only on lots that are at least 1 acre in size and that do not have municipal sewer and water service. The unit would have to use the same septic system and well as the principal residence.

Skogh believes his existing septic system and well could serve the accessory unit proposed for his garage and meet other requirements of the amendment, City Planner Allan Hunting said.

"There isn't anything so far that has made it impossible for them to meet the code requirements, at least as I understand it," Hunting said in an interview.

Proposed requirements

Further provisions of the amendment would require a granny flat to be 250 to 1,000 square feet and to house no more than three people. The unit would have to have at least two off-street parking spaces in addition to the one off-street space required for the primary residence.

The property owner would have to live in the primary residence or the accessory unit. The unit the owner does not occupy would require a rental license. Owners would have to register their accessory dwelling units with the city. The units would have to be a subordinate part of a single-family home and the design would have to be similar to the primary residence and be compatible with surrounding homes.

The city has received several inquiries about accessory units and proposals to include them in new homes or remodeling projects, but the current code required eliminating full kitchens planned in accessory spaces, Hunting stated in a report to the council. Some properties in the city may have unapproved granny flats, likely in homes built in the 1950s and 1960s that included full kitchens in their basements, according to discussion of the granny flat amendment before the city's planning commission. The number of such properties isn't known.

In addition to the Dakota County cities that allow granny flats, other metro-area suburbs that have given the OK include Bloomington, Shoreview, Richfield, Rose- ville and Plymouth, according to the summary Hunting prepared. Richfield, Roseville and Farmington allow them in both homes and accessory structures, as Inver Grove Heights is considering, while Plymouth allows them only in accessory structures.

Todd Nelson is a freelance writer in Woodbury. His e-mail address is todd_nelson@mac.com.