Troy Hannigan started architecture school thinking he’d wind up designing “cookie-cutter suburban homes.” But in 2007, during his third of five years in Philadelphia University’s B.Arch. program, he joined the school’s new chapter of a group called Freedom by Design (FBD). He soon found himself helping to design a wheelchair ramp inside the home of a 19-year-old named Josh Skoog, who has cerebral palsy, and he began to think about architecture quite differently.

Josh’s house, in Collegeville, Pa., where he lives with his parents, Peter and Marnie Skoog, had a couple of steps between the kitchen and the family room, which Josh had been negotiating, with difficulty, via a makeshift wooden ramp. (Josh once fell off the ramp and broke his hip.) In its place, Hannigan and other students in the FBD program built a longer, more stable ramp so Josh could move around his own house. Still, Hannigan didn’t expect what he saw while visiting the Skoogs one day after construction was done: Josh walked down the ramp by himself into the family room. “It was a complete shock,” Hannigan says. “He had total freedom on the first floor of his house. That really—.” His voice trails off for a second. “Well, you know what I mean.”

Hannigan has since graduated and works for Habitat for Humanity in Philadelphia through the AmeriCorps Vista program, helping to plan projects and acquire properties. Freedom by Design “really changed how I see architecture,” he says. “It’s not about making a cool building but about who’s inhabiting the space and how they’re living in the space.”

FBD turned five years old this year, and in that short period it has been changing the minds of many architecture students across the country. The idea started in Denver with a practicing architect, Brad Buchanan, a principal of the Buchanan Yonushewski Group. His firm’s staff had been joining volunteer days with Habitat for Humanity, and he realized that there was a huge population of older and disabled people—people that architects weren’t serving but for whom modest design improvements could make huge differences in everyday life. The firm began seeking out its own pro bono clients. Other firms in town grew interested. “Next thing you know, we had 20 projects going,” Buchanan says.

The pro bono work easily could have taken over Buchanan’s business. “I knew we needed help if we wanted to keep it going,” he says. So he found the idea a new home with the American Institute of Architecture Students (AIAS), where it took on the motto “Improving the safety, dignity, and comfort of our neighbors.” Nationwide, FBD now has 57 chapters at schools in 35 states, plus one in Toronto, says Matthew Fochs, director of design and outreach programs for the AIAS. “We fit that niche market where, even in today’s economy, contractors and developers won’t touch the work because it’s not worth their time to commit to a handrail or something.”

FBD projects are deliberately limited in scale: difficult enough that people with disabilities or their families may not be able to get them done themselves, but not so large or so costly as to be out of college students’ reach on weekend schedules and with donated time and materials.

At Southern Polytechnic State University, in Marietta, Ga., Mandy Palasik helped run two projects in 2008 for Marcella Genut, an 11-year-old girl with muscular dystrophy. First came new carpet, to make it easier for Marcella to get around her house in her wheelchair. Then came a patio extension in the sloped backyard, where students built retaining walls topped by planters, so that Marcella could garden from her wheelchair.

In the course of their FBD projects, students learn to look for clients (the needs are great, but finding clients is harder than expected), interview them, and focus acutely on their abilities. The students typically have professors and volunteer contractors at hand to help mentor projects and make sure things run smoothly.

“It’s not just a bunch of kids,” notes Peter Skoog. “They were being overseen by professionals. That took a lot of stress off our end of the project.” And as for those kids, he says, “They were just great to work with. They still come out and visit. It’s been a positive experience, for us and for them.”