Nicholas Turner and his wife, Theresa Trzaskoma, looked for an apartment for six months, but nothing seemed right. When they entered a triangle-shaped apartment at 90 St. Marks Ave. in the Prospect Heights section of Brooklyn, however, they knew immediately that they were home.

“It was totally bright and spacious,” Mr. Turner said of his first look at Apartment 3. Other buyers might have disliked the wedge-like shape, but to the Turners, the layout made the space special.

“It’s shaped like you’re on the prow of a ship, pointing to downtown Brooklyn and Manhattan,” Mr. Turner, who put the apartment on the market this winter after living there for nine years, said. “We loved its uniqueness.”

Apartments with unconventional shapes are rare in New York City, with its street grid system and large stock of rectangular and square pre-war apartment buildings. As real estate sales volume slows in an uncertain economy, owners of apartments with unusual features often find them sitting on the market longer than other homes.

They should hold off on making panicked calls to their contractors, however: Brokers recommend accentuating, rather than disguising, distinctive architectural features.

While quirky apartments may appeal to a smaller segment of the market, they tend to inspire a fierce devotion in the buyers who do like them, brokers said. “If it’s unique and different, you may not have as many people looking, but you’ll also get people who fall in love,” an associate broker at Gumley Haft Kleier, Robert Morgenstern, said.

The broker who is representing the sale of Mr. Turner’s apartment, Rezwan Sharif, said triangles are somewhat common in New York office buildings but scarce in residential spaces. “We rarely see a triangle building that is an apartment complex,” he said.

Mr. Turner’s family now includes two children, and they need a bigger place. Though they aren’t planning to move until December, they placed the apartment on the market in February to give themselves plenty of time to sell. They also have reduced the price to $879,000 from $969,000.

“We built in a lot of cushion,” Mr. Turner said. “We wanted to have some lead time.”

Unusual layouts can present design obstacles in the form of lost space, a challenge that appealed to Mr. Turner, who said he was surprised when he climbed three flights of stairs to discover a light-filled apartment with 11 windows. “It’s one of those secret New York spaces,” he said. “We were taken with how loftlike it was.”

The advantage of his wedge shape is the openness of the apartment, he said, which he and his wife emphasized by removing a three-quarter-height wall that separated the kitchen from the living room, replacing it with an island.

“The challenge is making use of that open space in a way that makes sense,” Mr. Turner said. “You have to have an eye for how to organize and design the place.”

With the pace of apartment sales in Brooklyn slowing 43.6% in the second quarter of this year compared to the year-earlier quarter, according to a report by appraisal firm Miller Samuel, buyers are taking longer to make decisions, an effect that is more pronounced with unconventional apartments. “Right now, people are playing it safe,” a senior sales associate at Corcoran, William Herbst, said. “People are worried about resale value, so anything too unusual that won’t appeal to a broad range of buyers will give them pause.”

But a distinctive feature that gets buyers’ attention can also provide an advantage, Mr. Morgenstern said, setting it apart from other homes on the market.

If an apartment does have a distinct feature, “don’t put up a fake wall and waste the space,” Mr. Morgenstern said. Instead, sellers should use decoration and furniture to accentuate the feature’s desirable qualities, such as the openness of a triangle-shaped space.

There is a big difference between an interesting architectural detail and a layout that’s simply undesirable, such as a master bedroom that can only be entered through the children’s rooms, however. When renovating an apartment, sellers must be careful not to introduce any undesirable elements into the space, Mr. Morgenstern said. A seller who doesn’t cook should not use that as an excuse not to renovate the kitchen, for example, and bathtubs should not be replaced with standing showers; buyers with children need tubs.

“Renovate it so that you’re happy, but it is one of your biggest investments, so you don’t want to over-stylize your renovation,” he said. “Keep your buyer in mind.”