Homeowners go underground for parking space

DALLAS — Jim and Cynthia Moore wanted a back yard for their two young children. Jim Moore also wanted a three-car garage with enough room for a small workshop.

The problem was that he couldn’t fit both on the 50-by-150-foot lot they purchased in the Dallas area.

So the couple took an unconventional approach: They built an underground garage with an $11,000 stainless-steel turntable so they don’t have to back out the steep driveway.

“When you have to leave, you back onto the turntable, hit the button (and) it spins you around,” said Jim Moore, owner of Urban Innovations, a Dallas development company that builds condos and townhouses.

Though underground parking is common in commercial and multifamily developments, it’s just beginning to make inroads into the single-family home market. At least half a dozen homes under construction in the Dallas area include underground parking.

With the record cost of land, Dallas area builders say, the number will grow.

Some people who desire underground garages want to leave more space for a back yard or a pool.

Others just want a bigger house.

Local builders say many of the homeowners opting for a basement or underground garage are transplanted Northerners accustomed to having a subterranean space.

“As land gets more expensive, you have to either give things up or try to find a different way,” Moore said.

“It costs less to put part of your house underground than by buying another lot.”

That’s why Ed Abraham started putting underground garages in all his company’s residential projects three years ago.

It adds about 10 percent to the cost, so a $400,000 house costs closer to $440,000.

“It gives them the ability to have at least a five-car garage,” said Abraham, president of Park Cities Custom Builders. “All my houses have five-car garages; some have six. Plus, it gives them room in the basement to do like a media room.”

Abraham said some of his counterparts have started building underground garages, too.

“The idea took off like crazy,” he said.

Steve Melman, director of economic studies at the National Association of Home Builders in Washington, D.C., said he hasn’t heard much talk about underground parking but noted that rising land costs have caused residential architects and builders to find new ways to accommodate cars.

“In the San Francisco Bay area, new-home garages are starting to be configured with tandem parking bays,” he said.

In tandem parking, one car is parked in front of another rather than next to it.

Valets typically park cars this way to maximize the available space.

Basements and underground garages are rare in North Texas for several reasons.

The biggest challenge is that most of the soil is clay, which shrinks and swells depending on moisture levels.

In the few areas where there isn’t clay, the ground consists mostly of white rock, which is hard to dig into. The prevalence of shallow groundwater is another hurdle, though it’s not as troublesome as the clay.

Kelly Walker, a University Park City Council member who is president and CEO of Benchmark Environmental Consultants, said the abundance of clay makes constructing anything underground a nightmare.

“I just cringe because you are constantly going to have a water problem,” she said. “You have to have a sump pump that runs continuously because you get so much water. That’s why houses move.”

Sump pumps are used in basements to remove water that’s accumulated in a sump pit, a hole to collect excess water. The pump generally feeds the water into a community’s storm water system. Abraham said building a basement is challenging but that a proper drainage system can prevent flooding.

“It’s the same principle of a high-rise building,” said Abraham. “They don’t have a problem with the garages flooding because they have the proper drainage system.”

Moore has a sump pump, a backup pump and a backup electrical system in his garage. Several drains stretch across the driveway to keep rainwater from streaming into the basement. In addition, the basement walls are made of foot-thick reinforced concrete, and retaining walls line the driveway to both keep the water out and the soil from shifting, he said.

Partly because the challenges scare many homeowners away from basements, area cities haven’t needed to develop many regulations in that regard for single-family homes.

Brad Martin, who owns Martin Custom Homes, said he’s getting lots of questions about the idea. He’s building a home with underground parking for three cars, plus a game room and utility room.

Martin said finding skilled labor is almost as challenging as keeping an underground space dry.

“We just don’t have a lot of skilled labor here that knows how to do basements,” he said. “When you say basement, everybody starts freaking out.”