Case Study: Spring Mill House by Robert M. Gurney, FAIA, Architect

Despite its glassy walls and an Olympic-size indoor volleyball court, Spring Mill is a house that keeps its secrets. It’s not until you walk inside that you experience the expertly knit public and private spaces and how the landscape participates in the interior. In part that’s because it’s built into a hill that slopes about 10 feet from the street to the back of the house, allowing architect Bob Gurney, FAIA, to sink the lofty volleyball volume into the grade. 

In fact, the house is designed around the clients’ love for the sport. A young couple with no children, they asked him to help them find a lot that would accommodate the volleyball court and generously sized entertaining areas, along with intimate spaces for themselves. The site they landed on, in a Northern Virginia suburb of Washington, D.C., comprises 3.5 acres with picturesque woods and pond and a slope to strategically minimize, if not quite hide, the bulky court. “This isn’t a family house,” Bob says. “It’s very client-specific, designed for a couple who likes sports.”

Wellness, relaxation, and other forms of exercise were priorities too. Stretched along the roughly east-to-west contours of a ridge that determined the house’s orientation, the interiors include a pool and spa, a gym and locker room, and a sizable game lounge. There is also a two-bedroom guest suite above the garage, a primary suite above the main entry, and a double-height living/dining volume with stacked offices. All of this, including the volleyball building, encompasses more than 18,000 square feet, but the staggered buildings, interwoven courtyards, and glass spine running through them help to minimize the scale. Along the spine, for instance, the architect has shaped scenes that pull visitors through the house and landscape, sometimes through subliminal cues. Each space reads differently depending on the time of day and the season, making the house a journey of discovery.

Indeed, it is the interplay of indoor and outdoor, public and private, real and perceived that elevates the experience to something beyond just another large, glamorous house. From the approach, the house reads as three two-story, rectangular boxes. At the gravel car court, the garage/guest volume is pulled forward to partially hide the volleyball volume to the left and define the central parking court. Above the garage are two en-suite guest bedrooms at the front and a sitting room at the back. 

On the central volume, glass doors beckon visitors into the entry corridor, which offers an axial view through the house—to the gym in one direction and the main living space in the other. Upstairs in the primary bedroom, separate baths and dressing rooms sit on opposite ends of the floor plan, and a mahogany-wrapped covered porch looks out on the trees to the north. But it is the main living volume that opens most dramatically to the landscape, and where the couple spends most of their time. The open-plan living room’s double-height glass walls bring in the leafy rear view of woods and sky.

Designed as a slatted glass box, the kitchen cantilevers beyond the main structure, creating an airy cooking core and room for a secondary prep counter and coffee station behind it. This main volume also stacks his-and-hers offices on the front façade. Perched on top,his office has a large window with electrostatic glass for nighttime privacy. 

Downstairs, a side wall of glass sliding doors off the living/dining room leads out to a large courtyard and a screened porch, which are also accessible from the spine and the entry pavilion. This area acts as the main hinge to the lower entertaining level through indoor and outdoor staircases. “The stairs at the living room courtyard take you down to the long terrace spanning the volumes and pool terrace,” Bob says. “It creates connectivity to outdoor spaces between different levels. No matter where you are, you have a view toward the landscape and park.”

Game On

The house has many social centers, adding to the sense of discovery. “There are a lot of public spaces in the house,” Bob says. “They entertain a lot around volleyball events, using the house as a central area to host friends, often overnight.” But volleyball isn’t the only game in town, and much of the activity spills out from the lower-level spaces. “The lower level has a very different feel than the double-height spaces floating above the landscape,” Bob says. “Here you feel you’re in the landscape; you experience it in a different way.” Under the living volume, for example, is a massive game lounge that flows out to a more intimate pool terrace and a covered eating area. “Originally we had the swimming pool outdoors, but they wanted to use it year-round,” he says. “We added a swimming pool and spa with a 74-foot wall of slide-and-stack doors.” Its skylit roof became a viewing garden along both sides of the first-floor spine between the entry volume and volleyball building. 

While larger conceptual issues permeated the design process, there were also practical matters to address: At some point, a scale this ambitious tips toward commercial construction. “The pool’s sliding door system was one of the largest we’ve ever done,” says builder Darren Kornas. “And the room had to be conditioned properly so the pool smell doesn’t migrate to the rest of the house. Ideally you want it so airtight that the water would stay in the room if you flipped it upside down, and there must be negative pressure so air is pulled into the room. We put in a standalone dehumidification system.”

Installing all the pool equipment inside the house raised other improvisational puzzles, such as how to get the 10-inch diameter pool heating vent pipe through the house and out in a place that everyone could agree on. To mitigate equipment noise, “we did mass-loaded vinyl in the walls of the pool equipment room, making sure every penetration was sealed up tight,” Darren says.

The volleyball building, of course, was another residential construction anomaly. From the backyard its full stature is revealed, though you catch an interior glimpse on an axial view from the game lounge. The second-floor guest suite has direct access, too. A flight of stairs descends to a small lounge and locker room overlooking the court and continues down to the court and a full bath and drinks station. Also on this basement level is a gym with a glass wall looking out on the pool and landscape.

Twelve-foot-wide footings were required to support the court’s massively tall poured-concrete walls, which measured 32 feet from footing to roof. “It looked like the Hoover Dam,” jokes Darren, whose crew handled the building’s commercial-style detailing. On the north side, a translucent polycarbonate panel admits natural light while eliminating glare, and the composite gym floor was chosen for its amount of “give.” “The clients visited volleyball courts all around the country,” Bob says. “They liked the look of open-web steel trusses and decided to leave them exposed.” This 50-foot-by-80-foot box has a Cor-Ten skin that echoes the entry volume cladding, while the garage and living volumes are wrapped in Shou Sugi Ban wood. “Cor-Ten is relatively budget friendly,” Bob says. “I knew I had to clad large expanses of walls and didn’t want to break the bank on an exterior material.” On the driveway side of the glass spine, slats made of FSC-certified mahogany provide a sense of privacy as you’re walking through the volumes and are a visual tie-in to the cantilevered kitchen.


Despite the volumes’ discrete functions, their palette of materials contributes to the fluidity of the floor plan. If the exteriors are minimal and crisply detailed, the interiors, too, form a quiet backdrop to pops of texture and color—particularly purples and oranges, which the clients requested. Flooring in the main living spaces is white oak, and Cambrian Cream—a natural stone quarried in Wisconsin—threads together the spine, exterior stairs and terraces, and lower-level spaces. The upper kitchen cabinets are oak with a custom gray stain, paired with lacquered base cabinets. Downstairs in the game lounge, the combination of raw and polished materials lends an appropriately lively vibe: a mottled wall of hot-rolled steel, reclaimed oak behind the bar, and a black Golden Eagle stone countertop with graphic gold-and-cream swirls. 

What is not as visible is the technology that addresses energy efficiency. Rooftop solar panels lighten the electrical load and support the zoned geothermal heating and cooling system. In addition, four Tesla power walls provide backup battery storage. “There’s an impressive mechanical room at the other end of the house from the lower-level lounge,” Darren says. If power goes out, he adds, this backup system is robust enough to run the spaces the owners use every day. 

Serving as a unifying element for the discrete boxes, the landscape grounds the house with its organic quality. Campion Hruby’s planting plan sets up a dynamic dialogue between the interiors and exteriors. A grove of trees animates the car court, along with clipped shrubs contained in Cor-Ten-edged beds. The plantings become breezier at the back of the house, where locally quarried stacked stone walls and swaths of native grasses define the terraces and a flat lawn for outdoor volleyball. Farther on, a path invites a stroll around the woods and pond. “The clients are super-private but I know they share their house with their group of friends,” Bob says. “The feedback has always been that they love it. I think their lives revolve around all the living experiences of the house.”  

Spring Mill House

Northern Virginia

Project Credits

Architect: Robert M. Gurney, FAIA, principal in charge; Nicole L. de Jong, AIA, project architect, Robert M. Gurney, FAIA, Architect, Washington, D.C.

Builder: Darren Kornas, ThinkMakeBuild, Annapolis, Maryland

Interior designer: Therese Baron Gurney, ASID, Baron Gurney Interiors, Washington, D.C.

Landscape architect: Campion Hruby Landscape Architecture, Annapolis, Maryland

Structural engineer: United Structural Engineers, Sterling, Virginia

AV consultant: Casaplex, Kensington, Maryland

Project size: 18,595 square feet

Site size: 3.5 acres

Construction cost: $295 per square foot

Photography: Anice Hoachlander

Key Products

Cabinetry: Gray-stained white oak, Kalamazoo (exterior), Poliform, Abet Laminati, Soho Vanities

Cladding: Delta Millworks Accoya Texas barnwood, corrugated Cor-Ten

Cooktop/Cooking ventilation hood: Gaggenau

Countertops: Golden Eagle, Stone Source

Entry doors & hardware: Pivot Door Company, Hoppe electric lockset

Faucets: Dornbracht, Fantini, Graff

Finish materials: Boffi, Stone Source

Garage doors: Clopay Avante

HVAC: Hottel HVAC, geothermal

Outdoor grill: Kalamazoo

Ovens: Gaggenau

Power systems: Tesla Powerwall

Refrigerator: Sub-Zero

Sinks: Elkay, Kohler, Urban Edge, Julien, Galper, Lavabo

Skylights: Wasco Velux Commercial Circular Units

Tubs: Azuma, Wetstyle

Volleyball court: Performance Sports Systems

Washer/dryer: LG

Windows: Fleetwood, Western Window Systems

Wine refrigerator: Sub-Zero