The story of David and Barbara Beers’s effort to renovate their mid-century modern home can be boiled down, ultimately, to THE windows.

A squat, airy, contemporary confection built in 1964 in Montgomery County, the house needed serious updating. But the Beerses were determined to maintain its clean, modern lines — and that meant keeping its 80-some windows free of details and embellishment, even as the glass and frames were replaced.

In a region where the center-hall Colonial reigns king, though, convincing contractors to stick with a modern aesthetic was no easy task. First, there was the general contractor who shored up the house’s glass atrium by building a not-quite-square frame using the wrong wood. Then there were the window company representatives who dutifully listened to David’s instructions for replacement windows — and ignored them.

“I told them exactly what I wanted: no molding, glass coming all the way down to the sill,” remembered David, who works as a painter and sculptor. “But then I came home and there it was: molding that extended from the frame.” A window’s frame is a small detail, but a significant one: rather than being a striking example of American modernism, the room looked like, well, pretty much any other 2000s-era space.

It was the last straw. David decided then to do most of the renovation himself, acting as his own general contractor and holding outside workers to his high standards. The house’s exceptional design and materials, he felt, deserved someone with an eye for detail who would highlight its strongest features, windows and all.

A distinctively contemporary community

Carderock Springs, the development where the Beerses’ house is located, is all about windows. Take a night drive through the area and it’s impossible to miss them: few homeowners seem to use shades, and the large, unadorned rectangles of light turn the houses’ exteriors into elegant Mondrian designs. During the day, the windows and the homes they belong to have a more subdued effect, but the architecture is distinctive, each house clearly part of a well-planned community.

Indeed, Carderock Springs — which sits just southwest of the intersection of River Road and the Beltway — is one of the Washington region’s best examples of mid-century modernism, developed 50 years ago by Chevy Chase native Edmund Bennett (who currently lives in Arizona) in partnership with the architecture firm Keyes, Lethbridge & Condon, a predecessor of today’s D.C.-based SmithGroupJJR.

In 2008, a community-led effort successfully pushed for the neighborhood to be added to the National Register of Historic Places, a few-strings-attached designation that recognizes the area’s architectural merit.

The 300-some houses in the community bear all the hallmarks of modernism: clean, crisp lines, open and uncluttered floor plans, cathedral ceilings, large entryways, and lots of glass. Most notable about the development, though, is its integration with the surrounding landscape, a style known as “situated modernism.”

“Bennett was really preserving the land, trying to minimize the impact of the houses on the terrain,” explained Isabelle Gournay, a University of Maryland architecture professor whose research, teaming with another professor, led to the neighborhood’s addition to the National Register. That element is still apparent: The houses are nestled into a rolling, wooded landscape, with each home’s design dependent on its siting.

In 1966, the houses sold for an average of $45,000 — expensive but not outrageous. These days, according to Mary Lou Shannon, a real estate agent who lives in the neighborhood, they go for between $700,000 and $900,000. The homes have worn well with time, she said, but most have been renovated, the kitchens and bathrooms upgraded and more living space added to the main floor.

But seriously updating the homes — whose exteriors, if not well maintained, can look a bit dated — is tricky. “You’ve got to be sensitive,” said Douglas Soe Lin, an architect who grew up in Carderock and still lives there. The houses speak their own language, he explained, one that needs to be heeded. “Everyone wants details, you know. But you put in a small trim and it changes the whole thing.”

A quick decision

David and Barbara Beers’s passion for maintaining their home’s original style makes them ideal Carderock homeowners. And in fact, this is their second house in the neighborhood. Barbara, who works for Microsoft, grew up in Carderock Springs, and the couple had been living in her old house, spending five years seriously renovating it.

But then the atrium house went on the market.

While almost all of Carderock’s houses have pitched roofs, developer Bennett took a chance in the mid-1960s and built seven flat-roofed homes, each clad in western red heartwood cedar siding and featuring a glassed-in atrium at its center. Distinctly more contemporary than anything else in the neighborhood, the houses were featured in House and Garden and Architectural Record magazines. But they weren’t particularly popular with buyers, according to Shannon, and Bennett stopped building them.

These days, the homes are in demand among Carderock residents and fans. Barbara Beers had long her eye on them, but she and David figured it would be forever before one opened up. Still, a couple of years ago David added their name to a waiting list to be notified when an atrium home was about to go on the market.

As luck would have it, one of the houses soon became available. The home, which had been owned by an elderly blind man, was in pretty bad condition, and the sellers had no interest in fixing it up before putting it on the market. So the agent in charge, Theres Kellermann, took advantage of real estate laws that give a seller 48 hours to find a buyer before publicly listing a property.

She turned to the waiting list. The Beerses were second in the queue, and the family that was first passed on the home.

“We had 24 hours to decide,” remembered David. The pair drove over and met with the home’s owner. “We didn’t have time to do an inspection; we just did a 20- or 30-minute walk-through. We had to believe that no one was hiding information about the place.”

It seemed like a good investment. The four-bedroom, three-bathroom house was selling for $900,000 and needed serious repairs. But the same model up the street had recently sold for over $1 million.

So they decided to jump. “Barbara really loved it,” said David. “I was less eager. I saw how much work there was.”

Highlighting strengths, fixing weaknesses

David was right: The house wasn’t in great shape. Forget burnishing its mid-century modern flair; the place had water damage and termite and mice problems, and the kitchen and bathrooms were still in their 1960s condition.

But the couple, who had learned more than a little about home repairs while fixing up their first Carderock Springs house, dove in. The house’s subfloor was rotting, and David — with the help of his extended family — tore it out, replacing some of the underlying joists and eventually laying down oak flooring.

Then came reframing the atrium and the disappointing encounter with the general contractor. David and Barbara eventually found a reliable window company from Pennsylvania to fix the atrium and install all of their windows, replacing the rotted frames and exchanging the leaky, single-pane windows for double-glazed, argon-filled glass.

For skilled work, like building a double-facing stone fireplace in the living room where a brick one had been, the couple hired outside workers. “But I did the quality-control stuff,” said David.

When the Beerses bought the house, the kitchen was still outfitted with a turquoise formica counter and the original harvest gold Frigidaire appliances. The couple tore down one wall to open up the room and hired a carpenter who built custom maple cabinets. The lines are clean, yes, but this is one room that doesn’t necessarily adhere to modernist principles, even if it is very functional.

When it came to the home’s exterior, though, there was no doubt about restoring the original look. The question was how. When the Beerses bought the place, the original cedar siding was coated in peeling layers of oil paint, latex and stain. David, who believed the underlying wood was still in good shape, was determined to get those coatings off.

“I got a bid to strip it to bare wood, and it was like $15,000 to $17,000,” he recalled. So he researched other methods, and eventually, watching “This Old House,” learned about an infrared heater, which he purchased online. The contraption is a small box that can heat a portion of the siding to 500 degrees until the paint blisters and can be easily removed. With two boxes moving simultaneously, David spent roughly three months scraping the cedar siding — which turned out to be in great shape, virtually free of knots — completely clean. These days, the rustic wood is the house’s most distinctive feature.

Of course, the Beerses haven’t adhered strictly to the mid-century modern theme: they chose to paint their front doors bright green, adding a purple trim to the home’s top and bottom. But that funkiness seems to meld seamlessly with the contemporary style.

They say there’s still a lot of work they want to do, such as planting the atrium and building a back deck and a studio for David. But the house feels complete. Walking through airy hallways whose cedar paneling matches the exterior, to a living room with giant, unadorned windows overlooking the woods, it’s easy to imagine that Edmund Bennett would approve.

Amanda Abrams is a freelance writer.