The 1892-built Fraser Mansion carriage house has a historic facade but a modern interior.

In the 1920s, families traveled to the corner of 14th and Church streets NW, a hub of auto showrooms, to buy Cadillacs and Chrysler DeSotos.

Today, the buildings at that intersection — which haven’t functioned as dealerships in decades — have nonetheless aged to perfection under a common denominator: People (still) want to fill them with essentials for day-to-day living. Now known as Lofts 14 and Lofts 14 Two, the buildings house condos, not cars. Completed in the mid-2000s, they’re the result of one of D.C.’s most fashionable movements (and buzzwords) in development: adaptive reuse.

Transforming old storefronts, factories and churches into living spaces is an idea born partly from necessity: Roughly 700 D.C. buildings are designated as historic landmarks, and 25 neighborhoods are protected within historic districts, according to D.C.’s Historic Preservation Office. That means anytime the owners of approximately 25,000 buildings want to renovate their exteriors or begin new construction, the city must first determine whether the work is compatible with the building’s history and architecture.

“D.C. has more properties designated [historic] than the average city,” says David Maloney, D.C.’s state historic preservation officer, noting that Boston, in comparison, has a mere 8,500 such structures. “Part of that is a reflection of … how historically rich [Washington] is.”

The structures’ former lives add to their appeal. Capitol Hill’s recently converted Residences at St. Monica’s (1340 Massachusetts Ave. SE), for instance, has history in spades. The 1908-built former Episcopal church is the new home of Tina Angelova, 30, who moved there with her husband and their 2-year-old daughter in late July. The couple were searching for a new property when they came across St. Monica’s, which was completed over the summer.

“I was, like, ‘Oh, wait, a church? That would be very cool,’” remembers Angelova, a senior manager of international tax at LivingSocial.

Her family’s $770,000, three-bedroom, two-bathroom condo includes stained glass windows in two of the bedrooms. It encompasses the church’s bell tower, which houses a bedroom and is accessed via a spiral staircase. Exposed beams and AC ducts, plus ceilings that reach up to 14 feet, counter the historic vibe with the modern, spacious feel of a loft.

In another St. Monica’s unit, an altar serves as a sort of memorial to the building’s original purpose. In a common space, the former church’s bell is a focal point.

“You can’t re-create those old, cool spaces, and I really think that’s what’s contributed to the resurgence of these areas over the last 20 years,” says James Nozar, the vice president of development at Chevy Chase, Md.-based the JBG Companies.

Some of Foundry Lofts’ units retain original architectural features, such as concrete ceilings.

Not far from the Residences at St. Monica’s, an older structure is thriving as converted homes. The Car Barn, an 1896 Romanesque Revival building — and the former streetcar barn, repair shop and administrative offices for the Metropolitan Railroad Company — was adapted for reuse and sold as condos and townhouses in the mid-2000s.

Current Car Barn resident Mike Sacks and his fiancée were intrigued by the building’s

history long before they lived in it. Now that they rent an apartment there, they “like the idea that we’re living in a building that was a depot for Washington’s now-defunct trolley system,” says Sacks, 29, a journalist.

Structures originally built for transportation-related purposes are a common trend in adaptive reuse. Another example is the Fraser Mansion carriage house (1735 Fraser Court NW), located several hundred feet from Fraser Mansion (which today houses the Church of Scientology).

Covered in ivy, the 1892 red brick carriage house looks like a fairy-tale cottage in the center of what is essentially an alley but feels more like a secret, back-street clearing in an urban forest of townhouses and brownstones. On the market for $2,699,000, the four-bedroom, 4.5-bathroom, 5,260-square-foot home is historic on the outside (it once housed 19th-century horses, buggies and straw). But its interior is designed in the style of a modern-day English conservatory, complete with a rooftop garden, garage and climate-controlled wine room.

“It’s important from the perspective of the pedestrian what the building looks like and what you can and cannot see,” says Rebecca Miller, executive director of the D.C. Preservation League, who explains that exteriors are often protected while interiors can be gutted and redesigned at an owner’s will.

The carriage house, which underwent extensive construction in the ’80s and more renovation in the late ’90s and early ’00s, is more or less a historic shell today — albeit one with alluring insides.

District Condos’ lounge-y rooftop, shown in a rendering, will restore a young vibe to a 1909 building.

Another facade getting an interior makeover is a seven-story, 1909 apartment building on the corner of 14th and S streets NW, under development by JBG. The building will be incorporated as District Condos, a seven-story, a 125-unit building with 18,000 square feet of retail.

Residents will enter through the main lobby in the historical structure and proceed to the larger, modern part, which is aimed at 25- to 35-year-old buyers, with shared amenities such as a roof deck, outdoor bar and splash pool. Sales begin next year.

Across town, an annex adjacent to Southeast’s Navy Yard is another future site of residences and retail. The annex and yard were at their busiest during World War II, when 26,000 employees worked in their 132 buildings. Today, finishing touches are being put on one of the development’s buildings, Foundry Lofts (301 Tingey St. SE), which is located in the former pattern and joiner shop, where ordnance was designed beginning in 1917.

The Foundry Lofts are part of a larger development called the Yards. When completed, the Yards will include 2,800 apartment and condo units; 1.8 million square feet of office space; and 400,000 square feet of retail and dining. Concrete columns and ceilings, as well as brick walls and large warehouse-like windows on lower-level units, are a reminder of the building’s industrial past. Residents will begin moving into the building’s 170 units, which range in price from $2,000 to $4,500 per month, in December.

“Preleasing has exceeded expectations,” says Ramsey Meiser, a senior vice president of development at Forest City, which developed the Yards. He says the complex’s distance from other residential neighborhoods hasn’t deterred interest.

If anything, the Yards typifies yet another boon to adaptive reuse in D.C.: an almost unlimited supply of historical buildings. “There’s always someplace new to go,” says Maloney, the state historic preservation officer.