When Rajesh and Ariel De bought their house in Chevy Chase, Maryland, they immediately tore down the 1940 red-brick Colonial and replaced it with a new traditional/transitional residence nearly twice its size.

“We needed to do things quickly because we wanted my elderly father-in-law to live with us,” Ariel De said. “He was using a walker and wheelchair, so the house needed to have an elevator and wide, open spaces.”

In 2013, they had paid a little over $1 million for the property, and the new four-story, 8,500-square-foot house added $1.6 million to the tab.

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The Des—he was principal deputy assistant attorney general in the Office of Legal Policy, White House Staff Secretary and general counsel of the U.S. National Security Agency during the Obama administration and is now the managing partner for the Washington, D.C., law firm Mayer Brown, and she’s a teacher—were busy with their careers and raising their children, Maya and Bodi, who are now 18 and 16, respectively, so they didn’t work on the interior until last year.

“Although the house functioned well, it was like a shell,” Ariel De said. “It was a hodgepodge of things we had collected, things from our family and discards from people that we got when we were starting out.”

The Des commissioned interior designer Kristin Harrison, owner of Virginia-based Bungalow 10 Interiors, to redecorate two rooms, but like many renovators, they got caught up in the project and decided to refurbish the entire seven-bedroom, six-and-a-half-bedroom house, which is sited on a fifth of an acre.

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“The redecorated rooms Kristin transformed were warm and homey,” Ariel De said, adding that they wanted spaces to entertain family and friends and hold fundraisers. The new rooms “made the rest of the house look bad. Once we started making the rooms nicer, we saw the possibility.”

During the eight-month project, Harrison used what she called a “mix of great quality things” to create an “updated traditional style with coastal elements” that has “comfortable places to eat, sit and serve guests while entertaining.”

This sounds easier than it was, she admitted, because the family possessed many “very distinct vegetable-dyed rugs” in dark, heavy colors that had to be incorporated into the design, which had a newly chosen soothing color palette of grays, light blues and creams.

The artwork created by Ariel’s mother, however, turned out to be perfect for the redecoration.

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At first, the Des were reluctant to part with items, some of which were heirlooms.

“Every time Kristin showed me a new piece she wanted to add, I would say, ‘Oh, my God, no, I don’t like it. That’s weird.’ But once all of the pieces were installed, everyone loved them. They really ground the house,” Ariel De said.

The Des donated the unused pieces from their collection to thrift shops and charitable organizations.

“The best part of the project was letting other people enjoy what we had enjoyed,” Ariel De said. “We have a huge community of low-income people and people new to the country here, so helping them was a gift.”

The Des are looking forward to hosting even more events, especially ones for Adaptive Tennis DMV, the nonprofit Bodi and Maya, both competitive tennis players, established to foster and expand the participation of disabled athletes in the sport.

“The reaction to the remodeling has been overwhelming,” Ariel De said. “There’s a greater intentionality and flow to the house. All of our guests love it.”

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Ariel offers more insight on the project: 

How do you describe your aesthetic… it’s casual and elegant, upscale, warm and inviting.

Biggest lesson learned/advice to others… is to work with someone you like and respect and enjoy spending time with so it’s fun. Something will always go wrong in a renovation, so try to work with people who will react well when it does.

Biggest surprise… is that it’s not just about a piece of furniture, it’s how the pieces of furniture work and flow together. You can like a piece of furniture you see in a magazine, but you have to consider balance, harmony, proportion and scale. I realized that working with a decorator is economical because it keeps you from making mistakes. Without a decorator, it’s like doing surgery without being a doctor.

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Favorite room after the renovation… I can’t choose only one because I love the whole house. I love the entryway, which has wallpaper and lighting and a round table that centers the space. It says “wow” to all who come in. I love the breakfast room, which has textured wallpaper, a large light fixture and a rustic table, because it’s immediately relaxing and special. In the family room, I love the extra seating, the wood and ceramic light, and the soft fabric.

Most dramatic change… is the kitchen. It was very dated—it was very ’80s, with low cabinetry and dark granite countertops. The bones were good, so instead of ripping everything out, we accentuated and improved what was there, creating a tall, bright and updated space that looks like Martha Stewart’s kitchen.

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A favorite material or product discovered during the process… was wallpaper. We didn’t have any before. We used it on nearly every wall, even ones that are solid color and look like they were painted. It adds texture.

Unexpected expense… the Calacatta Cremo marble for the kitchen countertops. It’s tan and cream—and very expensive. The neutral undertones went well with the rest of the house, and my husband fell in love with it. It wasn’t in the budget—it was $50,000!—but surprisingly, he made no fight about it.

Total cost of the renovation… was $300,000. The budget kept growing because initially we were only going to do a couple of rooms.