In a not-so-traditional house nestled in a traditional Northwest Washington neighborhood, a trio of design professionals has created a family home that’s a hybrid of worldliness and easygoing style.

The elegant 7,500-square-foot house in Berkley is home to Michael and Ally Banks — he a custom-home builder and developer, she a designer — and their four kids. Michael and Ally joined forces with architect Ankie Barnes of Barnes Vanze to design and build the sunlit house, which takes the Washington area’s familiar brick Colonial style to the next level.

“This was not your grandmother’s Colonial,” says Barnes. “I played with the proportions, the roof slopes, very tall French windows and doors, and lack of ornament to create a cleaner, slightly different, yet familiar house.”

The architect played with the proportions of the house, which has a lime wash exterior. (Goran Kosanovic/For The Washington Post)

The three-story, six-bedroom home in Northwest was finished in 2012. The brick exterior is frosted with a chalky white lime wash, a look inspired by both an English country home Michael and Ally admired in a magazine and a historical mill in Aldie, Va., that Barnes sent them to see. Inside are sophisticated, modern materials and finishes, such as weathered wood and unfinished raw steel. The couple eschewed formal details such as moldings and shutters. They even decided not to paint the mahogany windows. “When the beautiful, slender wood windows and doors arrived, the notion of painting them seemed like an anathema,” Barnes says. So they bleached them to get a cleaner look.

The more austere, subdued style was inspired by the philosophy of an influential Belgian designer. “All three of us love the aesthetic of designer Axel Vervoordt,” says Michael. The decorator, collector and antiques dealer designs sparely luxurious rooms curated with furnishings and art from diverse cultures and periods. “I love the balance of industrial and warmth.”

On the main floor the team created a neutral backdrop: Traditional plaster walls are coated with the same white lime used on the exterior, and floors are rustic white oak. “This allows for a quiet but beautiful background for art, antiques and modern pieces to work together,” Michael says.

The interior proportions add to the serenity. “This house is luxurious because it’s spacious,” says Barnes. “There is often not much space left in modern life. But here, ceilings are high. When you walk in, there is a sense of calm.”

A wall hanging shimmers in the foyer. (Goran Kosanovic/For The Washington Post)

The couple sacrificed a walk-in pantry to hang this large painting by Gary Komarin in the kitchen. (Goran Kosanovic/For The Washington Post)

The front door opens into a large foyer set off by a sweeping staircase, with the dining room on the left and library on the right. A metallic 1970s wall hanging by fashion designer Paco Rabanne shimmers above a vintage glossy black lacquer credenza. But it’s the view to the back of the house that draws the eye. Beyond the Eero Saarinen white oval table in the heart of the large kitchen is a dramatic glass-walled sunroom that sparkles with light even on a gray day and, with its comfortable furnishings, beckons in all seasons.

“The goal for the main floor was sunlight,” says Ally, whose firm is Ally Banks Interiors. “That’s why the windows and doors are so big and airy. Sunny spaces and light-filled open rooms are what make me happy.”

She says first-time visitors, perhaps expecting a more typical buttoned-up Washington residence, are surprised by the laid-back vibe. “They say the house reminds them of something in California,” says Ally, 41, who before moving to Washington worked in San Francisco as a buyer for Pottery Barn and Banana Republic Home.

The sunroom is one of the family’s favorite rooms. (Goran Kosanovic/For The Washington Post)

Although the Bankses had not intended to make the kitchen the hub of the house, it happened organically as they worked on the plans with Barnes, says Michael, 43, president of the Banks Development Co. There is a large work area and island and counters. The kitchen table, which sits in the dead center of the house and is where the family has dinner every night, is bathed in sunlight and is valuable real estate for both parents and kids. But there is plenty of space to spread out. Ella, 12, Hutton, 10, and Rowan, 9, can use the island or a nearby chair to hang out and study. Ruby, 3, can snuggle into a sofa in the family room or a vintage velvet armchair in the sunroom. The rooms in the house flow into each other yet provide lots of places to retreat.

“We live casually, and this house works perfectly for us,” Ally says. In the winter, the family might light a fire in the family room fireplace; inspired by Vervoordt, the couple installed a 100-year-old stone Belgian mantel. “I can be in the kitchen cooking and see all of them doing their homework in separate spaces,” Ally says.

Both the family room and library are one step down from the rest of the main floor, making their ceilings 12 feet tall rather than 11. The dimensions are inspired by New Orleans architecture. Michael says: “They are actually fairly small rooms, but they have very tall ceilings. This creates an intimacy and makes them feel special.”

Upstairs, the master bedroom is a work in progress, but the kids’ bedrooms are whimsical and fun. “I wanted each room to grow with the child, but I also wanted each to be a reflection of them,” Ally says. She searched out vintage love seats and French daybeds, bold wallpapers and modern Design Within Reach desks.

The Banks family. “We live casually, and this house works perfectly for us,” says Ally. (Goran Kosanovic/For The Washington Post)

Ally and Michael enjoy scouting shops, galleries and markets wherever their travels take them. “Our house is a collection of things we have found over the past 15 years,” Ally says. The pieces include a giant antique basket from Timor bought at a SoHogallery, a brass Moroccan lantern uncovered thrifting in Palm Beach, Fla., and an abstract painting by Gary Komarin spotted at a Ketchum, Idaho, gallery. The house was designed to be flexible as the family’s needs change or as the Bankses come home with a new piece of furniture or a painting.

With its distinctive style and room for experimentation, the house is a place the Bankses like to take clients for meetings. “It gives us the chance to show clients more possibilities,” says Michael. “Things like the plaster walls, the finishes, the proportions and how you can have a kitchen without any upper cabinets that has a very clean look. And how all this light makes for a happy house.”

The real success of the house is that it fits the family’s lifestyle and is durable enough to withstand it. “The boys literally skateboard on our first floor as though they are in a gym taking laps,” Michael says. “We used to scream at them to stop. We gave up.”

Jura Koncius covers style, home and design for The Washington Post.