The Flemish Revival-style townhouse was built in 1908 and once served as the Libyan Embassy. It is now a private residence. (Katherine Frey/The Washington Post)

In the early summer of 2007, H. Keith Powell was driving down Massachusetts Avenue just north of Sheridan Circle in Northwest Washington and noticed a sign in front of a white brick building.

“It said something about an auction or foreclosure on a building that was right next door to the home of some friends of ours,” says Powell, 58, who heads Potomac Maritime, a ship-brokerage firm. “The building was very run-down and in horrendous shape.”

The building was a Flemish Revival-style townhouse built in 1908 that once served as the Libyan Embassy. When Powell drove by, it had been unoccupied for 25 years following the end of the U.S. government’s diplomatic relations with Libya in 1981.

Powell was curious and arranged a walk-through. He began negotiating with the owner of the property, a real estate developer who had bought the building from the Libyan government and hoped to turn the 4,600-square-foot, four-level property into condos — a plan doomed from the start because of zoning restrictions in the neighborhood.

The building’s roof had been leaking for years, as pigeons and raccoons moved in. One of the side walls of the structure had partially collapsed, requiring a temporary fix that the State Department arranged so the house next door wouldn’t be damaged.

To keep the building from going to auction, Powell had to make a successful offer and convince his wife, Marianne Powell, 55, that buying it was a good idea. With a deadline clock ticking toward the auction, Powell made his case. “He told me I had six or seven hours to decide if we wanted to take on the project,” says his wife. “In the end, I said, ‘Go for it.’ ”

The property closed for $2,265,000, and Powell began assembling a dream team of architects, builders and designers to transform his Embassy Row problem child. He knew Anthony “Ankie” Barnes of Washington-based Barnes Vanze Architects socially and called him in for a consultation.

“It was the worst semi-abandoned house I’ve even been in,” Barnes says. “The back of the house was so dangerous you couldn’t walk into it — it was literally falling down.”

Powell spent the next five months huddled with architects, devising plans to stabilize the building by adding steel framing and building a wall inside the troubled sidewall. It took an additional five months to get approvals from D.C. zoning officials and the Kalorama Citizens Association to start repairs.

After a year of design and permitting, Powell brought in Tom Glass of Glass Construction, also based in the District, to start the overhaul. “We did all the structural work, all the foundation work, electrical, mechanical, plumbing, roughed in the kitchen, bathrooms, elevator and some of the restoration work,” Glass says.

The elevator caused headaches. It was already part of the house, but Powell wanted to add a roof deck and extend the elevator to the top level, and that required a zoning adjustment. Adding bathrooms also became problematic when plumbing crews trying to lay new pipes discovered large concrete pillars buried under the foundation.

Meanwhile, the family was still living in a large house in University Terrace as things plodded along. The construction lasted four years. The couple sold the house they were living in and moved in during the fall of 2012, along with their two young sons.

The renovated home is a tribute to the Powells’ vision and perseverance. The brick exterior, which had been painted white, was stripped, and the distinctive dormers on the top floor had to be rebuilt by hand.

To put the interior design on the right path, Powell brought in Martha Blair FitzGerald of Chevy Chase, Md.-based FitzGerald Interiors, who worked directly with Urban Country in Bethesda to give the home a traditional look with a nod toward France.

The first step was figuring out what would fit.

“They really downsized when they moved, and a lot of the furniture wasn’t going to work with the size of the rooms,” says FitzGerald. Entrance is gained through a foyer guarded by two sets of oversized oak and glass doors accented with custom wrought iron. The doors also had been painted, which required more stripping. They open into a formal living room accented with plaster molding and softened by an area rug from Carpet Impressions.

“We chose the color scheme for that room from the rug,” FitzGerald says. “The Powells spend a lot of time in Paris and Southern France, so we picked pieces that related to that.” With a theme selected, the rest of the house began to follow suit. A formal dining room separates the living room from the kitchen, a room where more challenges arose.

The foyer is guarded by oversized oak and glass doors accented with custom wrought iron by Chris Shea. (By Greg Powers)

In the family room, which looks out toward Rock Creek Park, French formal gives way to French Country. (By Greg Powers)

A curved wall and three windows on the sink side put storage at a premium.

Powell tapped Jennifer Gilmer of Jennifer Gilmer Kitchen and Bath in Chevy Chase, Md., to modernize the kitchen. Gilmer says she defined the design goal as “creating an open kitchen with good traffic flow in a style that blended with the time period of the house.”

Gilmer and her team addressed the storage issue with an entire wall of custom maple cabinetry. The countertops are Jerusalem stone, the fridge is Sub-Zero and the range and dishwasher are Miele.

The kitchen flows naturally into the rear family room, which looks out toward Rock Creek Park. In the family room, French formal gives way to French country with club chairs and a sofa from Hickory Chair.

The entire staircase, which also required a full renovation, opens on the second floor to the “ladies lounge,” defined by a Plexi-Craft writing desk and a chair-and-ottoman combination upholstered in fabric from Cowtan and Tout. Vintage botanical prints add to the traditional feeling of the space.

Down the hall to the back of the house stands the master bath, which has a marble-tiled shower and a stand-alone soaking tub from Waterworks. Twin vanities flank each side of the room. The master bedroom features a tray ceiling with a serene color scheme and an antique chandelier. Also on the second floor, there’s another lounge area — with a beamed ceiling and a brick fireplace — that looks out onto Massachusetts Avenue.

The third floor has the kids’ rooms, each with its own bath, and another small family room and an office. And on the top floor, there’s another lounge complete with wet bar and access to the roof deck.

The Powells’ dedication to the project is evident throughout.

Marianne Powell says she’s happy to be closer to downtown and loves city life.

“When we started, I didn’t know how many years it was going to take to finish it, but I love being here,” she says.

The driving force behind the project was clearly her husband, a man who enjoys an architectural challenge.

“My favorite thing about the project is we saved a beautiful house and brought it back from the brink in a great way,” he says. Powell declines to say exactly how much he spent for his labor of love, other than “it cost plenty, but I’m ahead of the game.”