For almost 100 years the two houses have faced each other on Potomac Avenue, fraternal twins designed by noted Dallas architect Hal Thomson. Both houses have survived changing styles and trends over the years, and with help from owners and designers who care they will stand for years to come.

“The architecture of Hal Thomson requires respect and deference from the architects that follow,” says J. Wilson Fuqua, an architect who, like Thomson, has spent much of his professional life on Swiss Avenue and in the Park Cities. “Our philosophy is that we respect what is there and use that to guide us.”

Fuqua has worked on both Potomac houses over the years for multiple clients, and most recently, the house on the north side of the street received his attention. Like its twin, the house was built in 1919 as a relatively modest yet stylish two-story home with white clapboard siding. A major addition in the 1970s doubled the 2,500-square-foot floor plan, but Fuqua says additions during that time were often overscaled compared to the original design.

“As an architect, it doesn’t cost any more to use good proportions. It’s just a matter of height versus the length and width of the rooms. In this house the rooms really felt good,” he says. “The interesting thing about this client was she was ready and willing to spend money to correct a lot of things that the previous owner had done that were not quite the best thing for the house. We returned the main part of the house back to the way it was originally.”

Architect Hal Thomson designed the original home that J. Wilson Fuqua later updated for his clients. “Our philosophy is that we respect what is there and use that to guide us,” says Fuqua.

The bespoke fireplace mantel was designed by Fuqua for the house. The mantel and ceiling molding, inspired by the molding above the second-floor eaves, are from Casci Ornamental Plaster. Cathy Kincaid was responsible for the interiors.

That began by reestablishing sight lines from the entry hall. “You couldn’t see into this really beautiful living room through the hallway,” Fuqua says. “I made it so that things lined up better. They were subtle changes, but they make a big difference.”

Working with Cathy Kincaid Interiors, Fuqua simplified the floor plan and incorporated details that fit the traditional style of the original house.

“The kitchen changed quite a bit,” he says. “It wasn’t a bad kitchen; it was just small. We opened it up so you can see through to the dining room.”

The new kitchen is modern in function but with a traditional and simplified style. Rather than install combinations of tile, wallpaper and paint, the walls are covered with tile alone. A large, vintage-style cooktop and range is topped by an oversize vent hood trimmed in brass.

Other nods to an elegant past include mosaic tile flooring in the master bathroom and decorative plaster details in the formal living and dining rooms.

“If we can, we try to save the existing floor,” says Fuqua, and in this house that was the 2 1/4-inch-wide oak flooring throughout much of the original structure. Outside, the original 8-inch cypress clapboard siding was matched wherever exterior walls were changed.

The homeowner selected wallcovering from Zuber that represents each of the cities where her daughters were born. The original Jupe table from O’Sullivan Antiques sits on a rug from Stark.

Avian watercolors from Graham Arader line the walls at the top of the stairs. The pair of lanterns is from Robert Kime.

Fuqua says a primary goal, as in many restoration projects, was to bring in plenty of natural light and create good views to the exterior. A long skylight illuminates an otherwise dark second-floor stair hall and the first-floor hallway below. And a deep, enclosed back porch was brightened with another oversize skylight.

Upgrades on the second floor included new bathrooms and what Fuqua calls “remedial corrections” to previous projects. The 1970s addition has taller ceilings that provided opportunities for improving the space.

This sumptuously furnished sunroom offers seating for reading or listening to music. A rug from Stark ties together the various fabrics and trims from Claremont.

The mosaic tile in the master bath is from Ann Sacks and was chosen to complement the Danby marble used for the tub and sink. Faucets are from Waterworks.

“The way that I work with clients is I like to be involved with the project all the way through,” Fuqua says. “A lot of the good things we did on this project ended up happening later on. You can’t foresee all of the opportunities up front.”

Such was the case when the owner decided she wanted an elevator running from the basement to the third-floor attic. Making room for the elevator equipment led to expansion and improvements in the basement, including an antique coal-burning fireplace, media room and wine tasting room. A new brick floor was put down and directional lights were hung from the floor joists above. In part to hide elevator equipment on the roof, a skylight was installed above the shaft that brings light all the way to the basement through glass windows on the elevator door.

“Whatever we do, we try to make it look as if it was original to the house,” says Fuqua. “We try to take the best of what the original architect did and use that to guide our new work.”

Jeff Hampton is a freelance writer based in Garland, Texas. Find out more at jeffhamptonwriter.com.

Fuqua used faux bois pine by Barry Martin Paint to create a cozy inset in the master bedroom. The bedding is from Leontine Linens, with drapery from Colefax and Fowler, and the bed canopy and dust skirt come from Penn & Fletcher.