Prospective homeowners will go to great lengths for a beautiful view. Washington, D.C.-area custom builder Gabe Nassar and his wife, Ann Gamber, are no exception. When the couple bought a circa-1953, two-bedroom house in 1994, they did so for the opportunity to live right on Lake Barcroft, a peaceful body of water in the Northern Virginia suburbs. “The house was uninhabitable at the time—a wreck,” remembers Nassar. “It took six months to make it livable.” They stayed there for eight years, enjoying the lifestyle afforded by the lakeside dock, tranquil water views, and nearby private beach. But as their family grew to include three boys (and at last count, three dogs) they realized it was time to start the full-scale renovation they'd always planned to do.

They enlisted architect David Jameson, with whom Nassar had worked on several previous projects. Although the couple's program was fairly extensive—they wanted to add on another level containing bedrooms for the three boys, a homework room, and a master suite, as well as redoing the first floor and lower level—they also hoped to reuse as much of the existing structure as possible. “It seemed wasteful not to,” says Nassar. Adds Jameson: “I'm a big fan of reinventing these types of houses.” The building was in relatively good shape, thanks to Nassar's earlier renovation efforts. Repurposing its frame rather than tearing it down would allow the family to save money, conserve resources, and live in the house for most of the construction process.

So Nassar's crew cantilevered the new level over the original house's gently sloped butterfly roof. Subcontractors installed ductwork in the floors of the new second story, working in the cavity provided by the roof's distinctive shape. Later, they tore out the old roof and installed a dropped ceiling underneath the ducts. Along with adding this new layer to the house, Nassar and Jameson opted to gut the first floor and lower level, which opens out onto the backyard. They turned most of the former into a spacious family room and kitchen, and created a triple-height formal living area downstairs. The new, top-floor master suite looks out over the living room, through a curtain wall of glass, and onto the yard and lake outside.

The house's main public spaces feel expansive, in part because of Jameson's suggestion to pull the existing rear wall a few feet toward the water. Nassar agreed, though it meant more effort and expense. “When you work with a general contractor client, you can propose things you might not be able to do otherwise,” Jameson says. Nassar, an avid motorcycle rider and mountain biker, is always up for pushing himself to explore new challenges, and that personality trait merged well with Jameson's desire to take the house far beyond its previous limitations. In another bold move that gives the house much of its dynamic quality, they cantilevered the corner containing the boys' bedrooms 7 feet in one direction and 6 feet in another.

A varied palette of natural materials clads the home's new rear façade. The mix of elements—stone for the home's base, glass and mahogany for the master bedroom tower, and painted wood for the kids' bedrooms—breaks down the massing, so the 5,800-square-foot building doesn't appear significantly larger than its neighbors. “There's a juxtaposition of heavy and light materials,” Jameson says. “Also, the deck is very important scalewise. There's a layering from ground to sky.” The horizontal character of that layering reduces the verticality of the three-story building—a smart maneuver on a street full of two-story homes.

The front and sides of the house, too, received a new coat of materials. Nassar and Jameson kept the first level's existing stone cladding and extended it up 6 feet higher. Cement stucco painted a dark gray-green covers the upper story, again emphasizing the home's horizontal nature rather than its height. The stone was quarried within 20 miles of the house, in keeping with Nassar and Jameson's desire to stick with local materials as much as possible. “None of this is shipped from overseas,” Jameson says. The strategy reduced the amount of fossil fuels required to transport materials to the site, and it underlines the down-to-earth nature of the project. Oak floors and cabinetry, handrails made by a local welder, and off-the-shelf hardware: all of it is high-quality but not exotic, which is just the effect Nassar and Gamber hoped to achieve.