They started lining up at 9:30 p.m. Sunday outside the redbrick rowhouse on 24th Street NW. They weren’t waiting to vote, or for concert tickets, or for a table at the hottest new restaurant.

They were waiting in the cold and darkness for an appointment to buy a condo.

The sales staff at Westlight, the 71-unit luxury building in the West End developed by EastBanc and JBG Companies, was accepting appointments starting noon Monday for later in the week when buyers can put down a contract on one of the first 20 units being released.

No incentives were being offered such as a month free of condo fees. Nor were there discounts in price on the units, which start at $625,000 for 631 square feet and run upward of $4.4 million for a 3,051-square-foot three-bedroom residence. They were simply waiting in line for an appointment.

With this appointment, a buyer could write a contract on a unit. Given the intense interest, several of the units are likely to receive multiple offers, meaning some of the people waiting in line may end up with nothing if their contract is not accepted by the developer.

Seth Lubran was first in line, arriving at 9:30 p.m. Sunday. He was holding a place for Daniel Heider of TTR Sotheby’s International Realty.

“I felt like being the first person,” Lubran said.

Lubran came well prepared for his wait. He brought a red portable lawn chair, a bag of Cheez-It crackers, pretzel bites and 1.5 liters of soda.

“Not as bad as I thought it would be,” Lubran said of the cold weather. “If I would have known [the temperature would drop], I would have worn sweatpants.”

To make the wait as comfortable as possible, the sales staff at Westlight hired Leopold’s Kafe to provide coffee and hot chocolate to those waiting, ran extension cords out of the office so that people could power their phones, and passed out hand-warming packets.

“We wanted to make this as civilized as possible,” said Mei-Mei Watts Venners, director of sales at Westlight.

Venners said her team had thought through the ways to handle the anticipated crowd. They decided not to use email or phone because of the ways those systems can fail or be manipulated. Instead, they chose to have people wait in line because it would be the most fair and equitable. They picked noon as a start time, hoping at worst people would start showing up early in the morning.

“I really didn’t think we’d have people camping out overnight,” she said.

Most of those waiting in line were paid line holders or real estate agents representing buyers. Patrick Chauvin of Compass spent Sunday calling his clients explaining his plan to have people wait in line and then hiring line holders.

“It’s our butt on the line,” Chauvin said. Compass had 12 of the first 20 spots in line for their clients. “I like the process, actually.”

Woe the real estate agent who has to explain to his client that the reason he missed out on a coveted condo was because he did not wait in line or pay someone to wait in line for him.

Chauvin pointed out that as crazy as people waiting in line for an appointment may seem, it is a good sign for buyers who get a ratified contract.

“It’s going to sustain prices in the building,” Chauvin said. “They are going to be coming into the building with equity.”

Sacha Moise of Evers & Co. Real Estate was eighth in line. He arrived at 11:30 p.m. Sunday. He said the building’s amenities and location fueled excitement.

“This is a down-sizer’s dream if you’re living in McLean or Potomac and want none of the maintenance and all of the convenience of living in a five-star hotel,” Moise said.

Designed by architect Enrique Norten, the building offers a 24-hour front desk, concierge, uniformed doorman, porter, 25-meter heated rooftop pool and fitness center. According to Moise, the views from the roof are some of the best in the city.

The District has not seen this level of interest in the opening of a condo building since the housing boom. While Westlight’s popularity says something about the dearth of sizable, single-floor condos in this city, it also shows how strong the luxury market continues to be.

The second set of units will be released sometime after the inauguration. The building opens in May.