See a modern ADU carriage house in St. Paul as part of the MSP Home Tour

Home expansions have often centered on building up or building out. But some Twin Cities homeowners are increasingly adding living space by building smaller, detached units in their backyards.

As municipalities around the country respond to a need for denser housing, they’ve relaxed old regulations about adding new independent living spaces on existing residential lots, spurring their growth. In official records, these new spaces are usually designated as accessory dwelling units (ADUs), but go by many names.

In Hawaii, locals know them as ohana (family) units. Other names include sidekicks, alley flats, backyard bungalows, garden cottages and laneway houses. Meanwhile, some homeowners refer to them as carriage houses, as is the case with one built in St. Paul’s St. Anthony Park neighborhood that will be one of two dozen homes featured in the upcoming MSP Home Tour.

Whatever you call them, they can be a great option for homeowners who want to expand livable space within the borders of their property. For Brian Clark and his wife, Sarah, the decision was easy to build a mini-unit on their existing lot, a practice that was common when they lived in Alaska.

They brought in Quartersawn, a Minneapolis-based design and build firm, to create a structure that could coexist with their 1913 house. While a beautifully designed space like this may seem like a vacation rental dream come true, the owners have plans only for hospitality, not commerce.

“We always thought it was cool to be able to offer this level of hospitality to guests, and we kept it in mind over the years,” he said. “We love the idea that someone can come to stay at a moment’s notice. In the future, it might even be a great space for a boomerang kid or for adult kids with partners and grandchildren.”

The project began with the 2022 demolition of a garage that Brian described as “falling down.”

Quartersawn architect and director of design Ali Awad said one of the challenges when taking on such a project in an already developed neighborhood is the logistics of adding electricity and running water. But, working closely with the city, they navigated the approval and design process.

“St. Paul requires that accessory structure sewer lines be attached directly to city sewers,” he explained. “The Clarks’ house is third from the corner, and the sewer was available at the side street, so we were able to dig there.”

Construction continued during the first half of 2023. And even with a few delays caused by the record snowfalls at the beginning of that year, it was move-in ready for late-summer visitors.

On the first level, the new space features a two-car, 900-square-foot garage with in-floor heating and a drain, bike storage and a dedicated area for the homeowner’s woodshop. Up the stairs is a 579-square-foot living space that includes a kitchenette, full bathroom, one bedroom and a washer and dryer.

The interior design features a modern Scandinavian vibe, most notably in the birch plywood paneled ceiling, which Awad pointed to with pride. “It’s a nice way to warm up the room with natural materials without breaking the bank,” he said.

In the kitchenette, simple white flush-door cabinets blend with the wall for clean lines.

Awad designed two of the rooms to offer flexibility. The front room acts as the living and entertaining space while the back room can be used as a bedroom, office or yoga room.

In a space intended to be well-used for a busy family, easy-to-maintain and durable finishes were important. “We used [luxury vinyl plank] flooring on the upper level and epoxy floor coatings on the lower level,” Awad said.

Another major focus of the project was creating energy-efficient spaces. “We didn’t want to run a gas line, so it’s all-electric inside,” Brian said.

“Happily, they had a power pole in the backyard between them and their neighbor, so that worked out great,” Awad added.

The space is well-insulated and well-sealed, and it includes a heat pump for supplemental heat and air conditioning. “Heat really won’t be able to leak out of this space,” Awad said. “That’s important because not only is a super-tight, well-insulated building better for the environment by using less energy to heat and cool, but it also makes for a more comfortable, less drafty space.”

Beyond the practical, the design still had room for a few grace notes. Awad said they designed a “little roof,” or eyebrow roof, over every entry, which is a lovely yet practical feature. “It offers some shelter if you’re entering a keypad number or using a key when it’s raining, and it keeps water away from the door. Plus, it helps tie the look of this building to that of the main house,” Awad said.

The design team also took this opportunity to improve outdoor spaces. The building is sited down a slope so as not to obstruct the view of the backyard from the house. From there, they created a secluded patio space with a fire pit between the existing house and the new building.

“With the paving, planting and lighting, that outdoor area really sings,” Awad said.

For Brian and Sarah, their new carriage house/ADU has worked perfectly as a hangout area for their family or for hosting overnight guests.

“For us, this is a dream space,” Brian said. “We’re so glad we could build it the way we wanted.”

MSP Home Tour

What: Self-guided tour of 23 homes in the Twin Cities, reflecting a variety of housing styles, neighborhoods and home improvements.

When: 11 a.m. to 5 p.m. April 27 and 28.

Where: Homes are located throughout Minneapolis, St. Paul and surrounding areas. Find a digital guidebook at MSPHomeTour.com. Print guidebooks are available at metro area public libraries.

Cost: Free.

Julie Kendrick is a Minneapolis-based freelance writer. Follow her @KendrickWorks.