Meadowlark Builders and Meadowlark Energy are moving into one space — a former schoolhouse on West Liberty Street that will serve as a living lab for green building practices.

Janet Miller | For AnnArbor.com

The 1874 building is old. It’s leaky. It’s dated. And it’s perfect for a complete green makeover, said Doug Selby, company president and co-founder.

Meadowlark president Doug Selby, design manager Melissa Kennedy and co-founder Kirk Brandon are pictured in an old schoolhouse on West Liberty Street where the company is conducting a green makeover.

Janet Miller | For AnnArbor.com

Since it was founded in 2004, Meadowlark Builders has operated in scattered locations, most recently at two residences and two warehouses, around Ann Arbor. Meadowlark Energy, formed in 2010 to conduct energy-efficient home retrofits, shares the space — and together they have about 39 employees.

It took the growing company two years to find the right space, Selby said. The companies moved in late November into the former Wagner School and have been slowly — as funds allow — remodeling. The building also has had three additions over the years.

It is a work in progress, literally. There was no heat for three weeks after the move. Meadlowlark was waiting for a new high-efficiency air source heat pump from Carrier, Selby said. “We were one of the first people to get one,” he said.

The new foam insulation packed beneath the roof is visible from the inside and drywall has been hung but not finished. There won’t even be a sign out front, Selby said, until finances allow, he said.

After sitting vacant for two years, the building was purchased in May by Fountain Investment Group, in which Selby is a partner. Meadowlark is leasing the building at a below-market rate in exchange for the green upgrades. It is the former site of Washtenaw Engineering.

While the building finally consolidates the growing company — Meadowlark doubled every year until 2010-2011 when it saw 20 percent growth — it is an incubator for green design and technology. It will be a place where new home and home remodel clients can come and see first-hand what green building means, Selby said.

The building represents the four main building periods for Ann Arbor homes: There’s the late 19th Century schoolhouse, a 1920s addition, a 1950s addition and a 1980s addition. With a high-pitched roof, hallways with flat and cathedral ceilings and dozens of nooks and crannies, it’s built like a house, Selby said. “The building is similar to residential structures. It’s a good case study.”

Virgin white pine boards dismantled during one of the school’s previous renovations were used for tongue and groove flooring in the 1980s office wing of the building. The wood, with large and knobby knots that can only come from virgin timber, can no longer be found, Selby said, but is living proof of the value of reusing cast-off materials.

Meadowlark installed the new-tech air source heat pump and will later install a geothermal unit to test which heating system works best. “We call it dueling heat pumps,” Selby said.

They’ve already installed different types of insulation and venting in the building to test the efficiency of each. They’re even testing light bulbs.

“We will find the best way to improve the building over time, and be able to use that to come up with good solutions for customers,” Selby said.

Meadowlark will continue to seal the building and will install solar panels. Within three years, Selby said the 9,000-square-foot building should be carbon neutral, producing all of the energy it uses. For now, Selby said he hopes to have enough of the work done to have a grand opening next fall.

The new space will also allow Meadowlark Energy, which handles smaller energy-efficient renovation projects, to grow, Selby said. For now, Meadowlark Builders out-muscles Meadowlark energy in size, and Selby expects Meadowlark Builders to grow 20 to 30 percent in the new space.

But he expects Meadowlark Energy to take off. The call for the kinds of services Meadowlark Energy offers — energy auditing, insulation, windows, doors, plumbing and more — is high in an area where almost all the housing stock is energy inefficient.

“That’s the growth industry,” Selby said. “You can put a granite countertop in and it starts losing money on day one. You can install a new furnace or insulation and start saving money. There’s a huge legacy of underperforming houses.”

Janet Miller is a freelance reporter for AnnArbor.com.