Often overlooked in the core of the city of Detroit is an array of impressive cultural and commercial buildings constructed nearly a century ago. One of those 1920s buildings, called the Green Garage, is escaping obscurity in the 21st century on the wings of a sustainable rehabilitation undertaken by Tom and Peggy Brennan.

Tom’s interest in sustainability began with his membership on the board of the River Raisin Institute in Monroe, Michigan, which seeks to develop, revitalize, or preserve sustainable systems of living. When Tom retired from property management consulting in 2001, he asked his wife to join him in studying sustainability. Peggy was studying library science at the time; she thought a project of their own would give her flexibility for their family.

In the fall of 2005, they formed the Great Lakes Green Initiative, a sustainability study group. A dozen or so people met weekly in the Brennans' home. A monthly evening meeting, also in their home, attracted up to three dozen people from all over, Peggy said, but many from their church. Their study led to wanting to establish a green demonstration project. The Brennans wanted a building near a university so students could participate in the live laboratory. They were looking in Ann Arbor, home of the University of Michigan, until a friend pointed to midtown Detroit.

“We tried not to bring anything new into the building,” Peggy said. For example, the insurer behind Kanners & Patrize Shoe Co. had required the windows be bricked-in to prevent vandalism. The Brennans removed those bricks and turned them into a low wall in the back hall of the building.

The couple also used repurposed material to construct a handsome indoor greenhouse that serves as a foyer. The walls are made of window frames discarded from a power plant refurbishment. (The Brennans were on a bike ride when they spied the frames in a pile and begged to have them.) All told, the rehabilitation generated only two dumpsters’ worth of refuse.

The renovation highlighted the original architectural theme found in the bowstring shape of the original exterior window transom fanlights and in the original bowstring-truss ceiling joist. (Bowstring trusses are used to support large open spaces with no supporting columns in the middle.) Though they seem like new, the massive timbers of the Green Garage trusses—concealed by a drop ceiling for eight decades—were revealed for the first time in the renovation.

The Brennans took advantage of the bowstring truss to create collaborative open workspace. There are no offices with ceiling-to-floor walls and doors. At the Green Garage, the tenants are called businesses-in-residence. Their workspaces have five-foot-tall office walls, and some have no walls at all. Some “offices” are a chair at one of three conference-size tables. A place at the table rents for fifty dollars a month.

In the back hall of the Green Garage, a tally of the pounds of trash produced per month is kept on a white board. On the Green Garage web site, energy-use graphs show spikes during peak months that—not unpredictably—span the cold and drab Michigan winters.

Natural light comes through solatubes, which are small diameter skylights covered with lenses of magnifying glass. Other conservation efforts include a robust recycling program as well as composting to feed the worms in the roof-top garden.

“It was a complex, multi-year thought process,” Peggy said of their project. Once a dream, now a reality, the Green Garage model of business shows that with patience, sharing, and community, profit can be built with restored faith in place.