Ann Arbor architects prototype accessory dwelling unit in their own backyard

The patio area of the architects' ADU in Ann Arbor. (T+E+A+M | Chris Miele)

ANN ARBOR – Accessory dwelling units, known as ADUs, have long been a topic of conversation in Ann Arbor. Over the years, city officials have approved new regulations for accessory apartments in an effort to offer more housing options in a city in-demand.

ADUs come in all shapes and sizes, from carriage houses and converted garages to basements apartments and additions. They are also hotly debated.

While some argue that accessory apartments are a means to alleviate the housing crisis and allow property owners to make supplemental income, others say they fear private investors could shift the single-family home landscape and that the units could change the feel of neighborhoods.

Local architects Adam Fure and Ellie Abrons decided to put their ADU design to the test -- on their own property. The husband and wife make up half of the principals at T+E+A+M.

Exterior of the ADU on Ellie Abrons and Adam Fure's property in Ann Arbor. (T+E+A+M | Chris Miele)

They began thinking about designing and building a unit on their property when the city approved new zoning regulations in 2016.

“We thought of it as a bit of a prototype,” said Fure. “We believe in ADUs as a policy. Ann Arbor has a housing shortage and needs more housing that’s concentrated downtown. It’s hard to densify or add any housing in these old single-family neighborhoods. ADUs are the only way to do that.”

The unit on Fure and Abrons’ property is 730 square feet and structural insulated panels make up its continuous shell. The project was completed in 2021 and took two years, largely due to delays during the COVID-19 pandemic.

Windows and skylights are strategically placed to allow ADU residents more privacy from the main home. (T+E+A+M | Chris Miele)

In Ann Arbor, the maximum square footage allotment of an ADU is determined by lot size. For lots that are up to 7,199 square feet, ADUs can be up to 600 square feet. For lots that are more than 7,200 square feet, ADUs can be up to 800 square feet. In both cases, an ADU can also be as big as the main dwelling’s ground floor; whichever is less.

The unit, which they’ve dubbed “Northwood ADU,” is an addition to their home. To their knowledge, it is the first building in Ann Arbor to have a frost-protected shallow foundation -- a method commonly used in Scandinavia.

“It’s essentially just a way to not have to dig,” said Fure. “You don’t have to dig a crawl space or a basement, both of which are cost intensive and labor intensive. The system is essentially a basin of foam.”

Inside the ADU at the architects' residence. (T+E+A+M | Chris Miele)

With a goal of minimizing material waste, the architects experimented with materials that were more common in commercial applications like fiber cement panels. They also utilized exposed materials to bring different textures to the space. What stands out in photos of the unit is the widespread use of pressed board.

“It brings wood warmth and is a little cheaper than buying wood or plywood,” explained Fure. “We experimented with exposing different materials and coming up with an aesthetic that might be a little unexpected and might encourage folks to try things a little differently.”

Light fixtures hang from a pressed board ceiling. (T+E+A+M | Chris Miele)

At the end of the day, they spent approximately $350 per square foot on the project, a cost that could be brought down on future projects, said Fure.

“We paid a bit of a premium because we were trying different cladding materials,” he said. “We paid more to do more detailed mixing of materials.”

He said he and Abrons are currently looking to design similar ADUs for other property owners, but that the unit is not one size fits all.

As for their unit? They rent it out.

“Everyone who contacted us said how unique it is to find an apartment in one of these neighborhoods,” said Fure.

Inside a prototype ADU in Ann Arbor. (T+E+A+M | Chris Miele)

According to the most recent ordinance, ADUs must have a minimum 30-day rental period -- a measure put in place to prevent homeowners from making their units short-term rentals, said Fure.

“What we like about the ADU is it allows the average homeowner to participate in housing more generally in the city,” he said. “It’s a good way to bring more people in. It’s a good way to produce more diverse options for rental units. We got a lot of interest pretty quickly.”

For more information, visit their website.

About the Author:

Meredith has worked for WDIV since August 2017 and was voted one of Washtenaw County's best journalists in 2019 by eCurrent's readers. She covers the community of Ann Arbor and has a Master's degree in International Broadcast Journalism from City University London, UK.