When David Carmel decided to propose to Kirsten Axelsen, he was at home in Manhattan and she was in Ethiopia, working to eliminate trachoma (the world’s leading cause of preventable blindness). No problem: David flew 7,000 miles to pop the question at a restaurant in Addis Ababa. A year and a trip to the altar later, the Carmels now live in a Chelsea apartment that’s designed in part to make it easy for David to get around in a wheelchair; a diving accident eight years ago left him paralyzed from the waist down.

Their home is the result of collaboration with architects Andy Bernheimer and Jared Della Valle, of Brooklyn’s Della Valle Bernheimer, whom David hired before he met Kirsten. The fact that the two architects are about his age was a plus, he says. “Jared and Andy saw me as a 20-something who wanted a great apartment—it had to be totally accessible but not look institutional.”

When David bought the place, his mother, Ann, and older brother, Jonathan, were also getting ready to move into the building—creating a vertical family compound. They had chosen the location because it is wheelchair accessible, with a street-level lobby and elevator access to the garage, where David now keeps his hand-operated van. But Bernheimer and Della Valle, the 2002 winners of the Architectural League of New York’s Young Architects Forum, couldn’t start construction on the Carmel apart-ments until the developers finished the interiors, which meant adding “walls we knew we were going to tear down,” Bernheimer recalls. (In New York, the building department won’t grant a final certificate of occupancy unless the construction matches approved blueprints.)

This waiting period gave the architects and David time to consider both the pros and cons of his new home. Facing north, the apartment David chose has glorious views of midtown, including the Empire State Building. But its layout included a living room so narrow that “it felt like a tunnel,” he says. David and his twin brother, Jason, who were sharing the space at the time, decided to make do with just one bedroom. By eliminating the second bedroom, the architects were able to create an L-shaped living room with more width and more windows. They also devised a sliding wall that allows the space formerly allocated to the second bedroom to be closed off from the rest of the apartment. This wall is made of Cymat, a kind of aluminum foam that is so light David can open and close it from his wheelchair. Behind the sliding wall, a storage unit conceals a Murphy bed, which is now used by guests. It moves up or down at the touch of a button.

When Kirsten entered the picture, she helped make a few changes to what had become a stylish bachelor pad. The first step was adding some color to the walls—but not without a careful plan of attack. She and David hung about 25 swatches around the apartment and left them there for several weeks. They finally opted to apply the shades they liked to individual surfaces rather than entire rooms. As Kirsten puts it, “We made canopies out of color.” In the open kitchen, where an island was removed to make it easier for David to navigate, the wall color—a grass green—helps delineate the space.