The North Pointe development on the edge of the historic district will feature green homes from the mid- 200,000's. (Katherine Frey/THE WASHINGTON POST)

Anyone paying attention to the “green building” market knows that most of the eco-friendly abodes that have proliferated across the country in recent years have been million-dollar trophy homes.

But the developers of the new North Pointe neighborhood in Frederick are taking things in the other direction: They’re building energy-efficient townhouses and duplexes geared toward middle-class buyers. The 55 homes start in the mid-$200,000s, but will offer the kind of “green bling” usually found in more upscale models: solar panels, geothermal heating and a sophisticated computer system to help manage energy usage.

Green homes come in many varieties. Some simply have ecofriendly features, such as recycled flooring or low-flush toilets. Others are tightly sealed boxes that the aim to conserve energy. All these types of homes have popped up throughout the Washington region. In the District, an ambitious $700 million project under construction at the site of the city’s former convention center plans to offer a mix of offices, shops and homes — including green roofs on all the residential buildings. In Bethesda, there’s a super-insulated “passive house” built to a German green home standard, which claims to require only 10 percent of the energy it takes to heat and cool a conventionally built house. Add to that the Frederick development, which also claims energy-efficiency feats.

Builders have been trying to corner the green market for years, and green homes have gained some traction in the past decade. The market in residential green building increased from $7 billion in 2005 to between $12 billion and $17 billion last year, according to McGraw Hill Construction’s most recent Green Outlook report. Yet, these types of homes still remain far from mainstream, and many who track the industry are still waiting for a big break.

“Everyone says that once the industry emerges (from the current housing crisis), housing will be reinvented and there will be no other way but green,” said Rick Schwolsky, editor-in-chief of the construction industry magazine EcoHome.

North Pointe, which stretches across a three-block expanse of Frederick’s historic district, aims to be one of the first “net zero” communities in this region, meaning its homes are designed to produce as much electricity as they consume.

For starters, the homes will be built with a tight envelope (walls, roof and basement), which should reduce the amount of energy needed to heat and cool them. The walls are made of structural insulated panels, essentially two pieces of super-strong recycled wood filled with nearly seven inches of insulation. A foam that expands to 70 times its size is sprayed on the rafters and bandboards, for more sealing and insulation.

Each home has roughly 20 solar panels, mostly on the rooftops, that absorb energy from the sun and convert it to electricity. During the day, when a family is at work or school, the panels generally produce more energy than the home needs. That energy is fed into the electric company’s power grid, and a meter on the home tracks the transfer. At night, the energy is credited back to the household, said Mike Murphy, executive vice president at Nexus EnergyHomes, which developed North Pointe.

“You will be using the credit from the energy you put on the grid earlier in the day,” said Murphy, a former project manager at Toll Brothers, one of the nation’s largest home builders. “So essentially, you’re not paying for the energy you’re using in the evening. It’s a give and take with the energy all year long. At the end of a 12-month period, the give and take equals zero in terms of the net cost of the energy.”

Hence the term “net zero.”

Other potential savings: Home buyers can recoup part of the cost of the solar and geothermal systems by applying for state and federal tax credits. For instance, the development’s 2,700-square-foot model home is eligible for $17,000 in rebates, said Michael Muren, the community’s sales manager.

Since the community’s model home opened in June, another home has been built. Seven buyers have put down deposits, Muren said. Five are under contract and will break ground soon. If sales continue at the same rate, construction of all 55 units could be complete within about 18 months, he said.

But the success of any green home or commercial building ultimately hinges on the upfront calculations about the habits and needs of the people who use them.

In the commercial setting, the nation’s leading green building certification program — known as LEED — has been dogged by allegations that some buildings it approved have failed to deliver the projected energy savings. In New York, four design and construction professionals made similar claims in a lawsuit filed against the group that administers the certification program.

Brian Uher, co-owner of Amicus Consulting Services, a Kensington firm that specializes in green building, said builders are only estimating a structure’s future energy usage. The actual usage could be off by 10 to 20 percent. Skilled workmanship and correct installation are also key, he said.

“There’s no magic here,” Uher said. “It’s all about quality control.”

At North Pointe, the developers used computer software to estimate how much energy each house would require, right down to the number of loads of laundry that a typical family washes in a month to the number of lights they switch on — or forget to switch off. The idea was to try and gauge how much energy a family uses and how much solar energy would be needed to offset that.

To encourage homeowners to be more mindful of their energy usage, each North Pointe home comes with its own private Web site, behind a firewall, that owners can use to track how much energy they use — “like a miles-per-gallon meter for your house,” said John Spears, an investor in Nexus who helped develop the system. From a smartphone or laptop, homeowners can even turn off the lights or sprinklers when they’re away.

But “if they install 15 plasma TVs or add a beauty salon in the basement, I can’t control that,” Murphy said.

North Pointe is part of a broader effort to revitalize the area. Frederick’s housing authority, which owns the land on which the homes will be built, agreed to defer payment for the land as each sale is finalized, which helped defray costs and keep asking prices down, Murphy said. It didn’t hurt that the land was previously developed — with roads, sidewalks and lights in place — so that construction of the homes could begin immediately.

On top of all that, Nexus adjusted its profit margins to make the numbers work and leaned on its subcontractors to do the same, Murphy said. Economies of scale worked in the company’s favor. Building communities, as opposed to just one home, helps tighten up the numbers, he said. Nexus plans to build hundreds of net zero homes in the Mid-Atlantic region.

Another reason the community’s prices are relatively low, Murphy said: “Solar costs about half of what it did a few years ago.”

Christine MacDonald is a freelance writer.