When Kathy and Michael Caisley started looking for a new home, they visited several condos and single-family homes.

"So many were brand-new, luxurious and unaffordable," said Kathy Caisley, a city planner. "Then there were a lot of generic, cottage-style homes; we would have had to sacrifice the look we really wanted." What they really wanted was a sleek modular home like the ones they'd been obsessing over in Dwell magazine, so they did some research.

"It seemed impossible," added her husband, Michael Caisley, a video game sound designer. "We figured it just wasn't happening in Chicago."

And for the most part, it isn't. Prefab housing often conjures up images of double-wides and trailer parks or the mail-order homes Sears popularized in the early 1900s. Overcoming the social stigmas associated with the homes, costs, as well as Chicago's strict building codes have been deterrents for many designers. But a friend introduced the Caisleys to Jeff Sommers, the owner of Square Root Architecture, who had the same dream.

Sommers is now at work on the Caisleys' prefab, a modern home Sommers describes as eco-friendly and designed for urban installation and one, he hopes, will be a prototype for new affordable housing.

"If every one of these homes reduces the urban heat effect, improves water management and lowers gas and electric use by 50 percent — and you multiply that by hundreds or thousands — that's a big impact," he said.

The concept of prefabricated homes has taken off in many parts of the country, with 30 percent of new home construction in the past decade, either prefab or made with prefab components, according to the Department of Housing and Urban Development.

Sommers, who plans to erect the Caisleys' home this summer in the West Town neighborhood, has been working with Chicago zoning officials for more than two years.

"Safety is always the main concern," said Bill McCaffrey, director of public affairs for the city Department of Buildings. "Prefab homes must comply with Chicago building and inspection regulations. The biggest issues are the copper pipes and electric conduits behind walls."

Architect Michelle Kaufmann, who designed a prefab home on display at the Museum of Science and Industry, said that working in Chicago — even on an exhibit home — was a challenge.

But Mayor Richard Daley and Buildings Commissioner Richard Monocchio encourage green building, said McCaffrey. And for the past year, Sommers and fellow architect Kate Votava have been working on a home for the Caisleys that meets Chicago's code requirements.

For a traditional Chicago project, licensed installers and city inspectors visit the site at every stage ensuring that plumbing, mechanical and electrical components are up to code. But construction for the prefab is being done out of state — at a factory in Middlebury, Ind.—so there is no city site to visit.

"This is a hybrid approach to prefab," said Sommers. "We are drywalling 90 percent in the factory and leaving those connection points visible for traditional inspections. The city has been very willing to work with us."

Tim Heppner, a consultant on the Chicago Green Homes Program, said the time is right for prefab in Chicago.

"We are starting to see the problems of pollution and people are saying, 'Wait a second. All of the old ways of doing things got us into this mess. We are looking for different ideas and willing to try something new,' " Heppner said.

"I went over the drawings, and everything looks good from an environmental perspective." Heppner said of Sommers' design, calling the architect a "pioneer" in Chicago. "This project is an innovative look at an old idea and if it gets going will be a really affordable, energy-efficient house in Chicago, and that's what we are all looking for," he said.

Kaufmann, a leader in green, modular home design, agrees that the time is right. She designed mkSolaire, a three-story, loft-style prefab featured in the Museum of Science and Industry's "Smart Home: Green+Wired" exhibit.

Modular home construction leaves behind 50 percent to 75 percent less waste than traditional building, causes less impact on neighborhoods, costs less and is safer for builders, said Kauffmann.

"It's crazy that we are still building buildings the way we have been for hundreds of years. It's so wasteful and time-consuming," said Kauffmann. "To think that the best way to build is on site is like saying cars should be built in driveways. It doesn't make sense."

Kaufmann is developing a community of modular buildings-- townhomes, live-work and multi-family—as part of the Aria neighborhood revitalization project in Denver. Julius Zsako, a spokesman with Denver Community Planning and Development, said that although modular makes up a small portion of the market, he hasn't heard of anyone having trouble getting permits.

Sommers expects the Caisleys' home to be a model for what can be done with prefab and green homebuilding. The home includes upgraded insulation to limit the conductivity through the walls, solar thermal panels and a ductless HVAC system, which is twice as efficient as a traditional model, easier to install and controlled room by room. Photovoltaic panels are a future possibility.

"I want to create something so great that even if you don't care about the environment, you will make the responsible choice because you'll save money," Sommers said.

He said his initial goal was to keep costs at $150 a square foot, which would include everything except the price of the land. But the Caisleys upgraded some of the finishes and appliances.

"The final cost should be about $180 to $200 per square foot for a 2,000-square-foot, three bedroom, two-bathroom, two-story house with an attached garage," said Kathy Caisley. "You couldn't buy a new house with those specs in that area."

Sommers' hope is that his work will lead to an amendment to the building code, making modular construction an affordable option for green housing in Chicago, as it is in Denver and other U.S. cities.

"It's not rocket science," Kaufmann said, adding that her firm has completed 55 homes in the U.S.

"Luckily, I think there could be a good outcome of the perfect storm of the financial and environmental crises happening at the same time. Everyone is trying to do more with less and be smarter about using technology — and green homes cost less to live in," she said.