Case Study: Chain Bridge House by McInturff Architects

The leafy neighborhoods along the Potomac River in Washington, D.C.’s privileged inner-ring suburbs offer an ideal combination of urbanity and livability. Yet their downside is the tight lots, closely spaced houses, and busy roads. Mark McInturff, FAIA, sought to preserve privacy when he designed a house for a married couple along the waterway that divides Virginia from D.C. Just minutes from the Capital’s commercial corridors, the half-acre property is small but parklike, plunging to a wooded creek ravine, while houses on the other side of the street overlook the Potomac River. 

The wife, who is from Morocco, wanted a house built around an airy, courtyard-like living room with high ceilings and natural light. She and her husband, a retired businessman, also requested materials that felt solid and permanent. Mark and his team are used to such challenges. “One thing I like about practicing in Washington is that we have an amazingly diverse international, educated clientele,” he says. “So when people come to us with an idea that has cultural significance to them, we run with it.”

Mark drew a three-part building that touches every setback on the allowable footprint. The structure consists of a double-height glass and steel core—the living room “courtyard”—bookended by two robust concrete wings with thick walls, smaller windows, and white stucco surfaces. Those wings contain the private spaces—kitchen, dining, and family room on the first floor, three bedrooms and a study above. With 6-foot-wide hallways as connecting hyphens, the three volumes are identical in width, but each one steps a little farther into the backyard to soak up the southwestern exposure.

The team’s design kept the general idea of a Moorish courtyard house but emphasizes strong geometries and the play of light and shadow. That second request, for a house with implacable solidity, led the architects on an extended search for the right materials or construction method. “The wife lived in Belgium during her youth, where people built out of thick, permanent materials,” Mark says. “They said, ‘we don’t want a house where it sounds hollow when you knock on the wall or step on the floor. She would walk in and knock on a double-layer stud wall and say no.”

Principal Peter Noonan, AIA, came up with the idea of using insulated concrete form walls for the two wings. From basement floor to roof, the walls are composed of a 10-inch poured-concrete core sandwiched between several inches of rigid foam. “One advantage of ICF for three stories is that you get an incredibly well-insulated mass,” Peter says. “We installed a geothermal system for both heating and cooling, and once you get the interior heated up or cooled down, these thick concrete walls hold that thermal environment. A lot of the Passive Houses use similar technologies.”

The floor structure is impenetrable, too. Thin Epicore steel spanning elements were embedded with radiant tubing and filled with concrete. “Our general contractor had a super foreman named John Maysak, whom we totally bonded with and frustrated on more than one occasion,” Mark says. “It’s a commercial concrete floor system with concrete framing like you’d see in Switzerland; you could drive a truck on it. Everybody prioritizes where they put their cost, and this was one place they did. In exchange we scrapped the idea of a putting green on the roof.”

Scrim Scramble

With privacy a major concern, the team created layers, suggestions of enclosure between the house and road. Arriving visitors drive through a screen of plantings, park in the forecourt, and cross a small mahogany “bridge” to the front door. (The subterranean garage is around back under the media room and courtyard, navigated with a precise, three-point turn). Inside, sliding mesh screens define the foyer and lightly veil the double-height central living room. Beyond, the living room’s sliding glass back wall opens to a porch, pool, and terraces. Motorized screens can drop down from the porch ceiling, turning the living room into a giant outdoor space.

Principal Colleen Healey, AIA, describes the house as “a small collection of large rooms—not cavernous, but comfortably proportioned. Many of the first floor rooms are generous, nonspecific spaces,” she says. “For the middle volume to feel like a courtyard, we had to go as big as we could; otherwise it would feel like a space to move through. The main room is 20 by 20 feet. The entry is 10 or 11 feet deep and can be connected to the living room when the sliding screens are open.”

Adds Mark: “The mesh screens can stack—open in the middle for a party so people can come blasting into the room, or they can open on the side. They’re a big toy, in a way.” Colleen worked with fabricators to produce the delicate GKD scrims. “They’re made of gold and silver material woven together, turned in alternating directions so you get a different look depending on the side you’re on,” she says.

Lightbox

Solidity and transparency conspire to trip a little light fantastic. In the central, tent-like space, five standard VELUX skylights were engineered to create 4-foot-by-20-foot openings where the two interior walls meet the ceiling. “We slid them all the way to the edges so that those masses on either side could feel like they were going up into the skylights,” Colleen says. A large round skylight in the middle heightens the sense that the ceiling is floating.

Upstairs, a bridge crosses the courtyard from one side of the house to the other along the front façade. In another nod to Moroccan houses, this two-story wall is fitted with mahogany louvers, matching the material on the volume’s exterior side elevations. Throughout the interior, sturdy, smooth walls are made from a double layer of drywall covered with Duroc and then plastered. But the light easily slips in. The husband’s office at the back of the second floor sits on top of the porch, gazing out to the woods and into the center of the house. In the master bathroom, the walls shoot up into a pair of skylights over the tub. And an abstract pattern of small squares punctures the upper wall between the private master suite hallway and the living room’s air space.

“At the Alhambra in Spain, baths have vaulted roofs and little squares about that size, punches of light,” Mark says, though “there’s nothing overtly Moorish about it. The boxes have pieces of glass, little lights in the bottom; we thought of it almost like candles.” Their placement was a puzzle, though. “If there are 10 squares randomly placed, what’s the logic?” he says. “There were way too many sketches of it, working around ductwork weaving through the wall.”

The house wasn’t easy to build on its sloped lot. Extensive excavation required general contractor Richard Hazboun to shore up the neighbor’s house and protect the ravine during construction. But the result is a solid yet graceful dwelling with a high-quality fit. Details were executed with Swiss-watch precision. “The massive floors are perfectly level from one end of the house to the other,” Richard says. “All the windows have the same reveals, floor to ceiling, so they needed to hit the bottom and top the same.” Parapet walls on the flat TPO roof hide the mechanical equipment and courtyard skylights, giving it a simple, cubic form from the street.

“There was a level of trust and friendship among everyone with a certain goal in mind,” John says of the team. “You really have to see this as human interaction, and out of it comes a house.”

 


Additional Photography

 


Plans and Drawings


Project Credits

Chain Bridge House

McLean, Va.

Architect: Mark McInturff, FAIA, and Colleen Healey, AIA, principals in charge; Peter Noonan, AIA, and Julia Jeffs, McInturff Architects, Bethesda, Md.

Contractor: John Maysak, project lead, Added Dimensions, Takoma Park, Md.

Landscape architect: Lila Fendrick Landscape Architects, Chevy Chase, Md.

Structural engineer: MC 1200 Architectural Engineers, Alexandria, Va.

Pool: Alpine Pool & Design Corporation, Annandale, Va.

Project size: 8,500 square feet

Site size: .5 acres

Photography: Angie Seckinger, Julia Heine


Key Products

Bathroom ventilation: Panasonic

Cooktop/vent hood: Gaggeneau

Dishwasher: Miele

Entry door: Forms+Surfaces

HVAC: Carrier

Kitchen cabinets: Boffi

Kitchen faucets: Blanco

Kitchen island: ALNO Kitchens

Lighting: Lutron, Eurofase, Mooi (interior); Progress (exterior)

Limestone flooring: Marble Systems

Master bath vanity: Boffi

Office cabinetry: Abernethy Sticks, steel by Steve Prudhomme

Ovens: Miele

Refrigerator: Miele

Rollup insect screens: Phantom Screens

Shower faucets: Fantini Rubinetti

Sinks: Boffi

Skylights: VELUX

Structural glass and steel: AK Metals

Toilets: TOTO

Tub: Boffi

Washer/dryer: Miele

Window shading: Lutron

No Comments Yet

Leave a Reply

Your email address will not be published.