Residents of a luxury condominium in Chelsea are blasting the building’s developers, Elad Properties, for owing them money, using shoddy construction, and ignoring their complaints. Elad, a unit of the Israeli-owned El-ad Group, has shot into the spotlight in recent months with its $675 million purchase of the Plaza Hotel, which it plans to convert into 200 condo apartments, in addition to retail space and a 150-room hotel.

The residents of 224 W. 18th St. are consulting lawyers and construction experts on their building’s problems and may file an official complaint, the president of the condominium’s board, Michael Chaney, told The New York Sun.

Suggesting that in his opinion, Elad would not preserve the historical and architectural integrity of the Plaza, Mr. Chaney said: “If I was on the landmarks preservation committee, I’d be very afraid. I find them in many cases to be unresponsive and to use stalling tactics. I would say this is a case of buyer beware.”

Dealing with Elad “is like a game of vehicular chicken, where they wait you out and wear you down, hoping you will drop the issue,” another resident of 224 West 18th, Michael Moore, said.

Asked for comment about the Chelsea residents’ allegations, an official of Elad Properties conceded the company can be slow to respond, but said that eventually it diligently repairs every problem.

“I wish I could fix things faster, and I have hired new contractors as soon as I found out the old ones didn’t succeed,” Elad’s vice president of construction, Yoel Shargian, said. “This has nothing to do with the Plaza. … We are trying with every project to do it better and better.”

The condo on West 18th Street is one of two buildings built by Elad and known as the Campiellos. The other is around the corner on 17th Street. The building boasts a 24-hour concierge, a live-in building manager and staff, an on-site garage with valet service, and a fitness center. The apartments, which range from 1,100-square-foot one-bedroom units to 3,884-square-foot three bedroom units, include high-end appliances and finishes. They were listed at $1.06 million for the one-bedroom apartments and $4.5 million for a typical three-bedroom unit when they opened in the spring of 2003.

“There were a number of things that we as condo owners have remedied ourselves,” Mr. Chaney said, “rather than waiting around for Elad, because we feel that in today’s market, a lot of a person’s net worth is in their homes.”

Elad allegedly owes the condominium $15,000 in back maintenance payments of units. “They have owed it to us for over a year, and our attorneys have contacted them, but they don’t respond,” Mr. Chaney said.

Mr. Shargian said he could not comment on accounting issues.

Mr. Chaney said he and other condo owners in his building have hired experts who are investigating to determine how much Elad might owe and whether, with legal and other fees considered, it would pay to file a complaint with the attorney general. A decision should be made in the coming months, Mr. Chaney said.

Mr. Moore, who is employed as a broker with Douglas Elliman, said that he believes Elad has been no more attentive to residents at its newest luxury residential building, at 49 E. 21st St. While working on a sale there, Mr. Moore said, he has found Elad “unresponsive to a punch list of items” a client has requested.

“In new construction, unlike when doing a resale, everything is built by the sponsor and is the sponsor’s responsibility to fix,” he said. “Elad is acting more like it is a resale.”

A former resident of the 18th Street building, Herb Seilberger, said: “I was about ready to have a breakdown from dealing with Elad, so I decided to sell my apartment and move.” Mr. Seilberger said he bought the two-bedroom apartment in July 2003 and sold it in September 2004, because “it was either sell the apartment or lose my health.”

Mr. Seilberger said he paid $1.08 million to buy the apartment and sold it for $1.499 million. That represents a 38% profit in about 14 months. But because he sold his apartment before two years had elapsed, Mr. Seilberger said, he had to pay $125,000 in federal and state taxes.

Chief among his complaints about the apartment was a 12-inch gap behind his kitchen wall that he said was filled with debris and garbage and let in a constant flow of cold air. He also said he had heating problems, which once led him to spend a weekend bundled up in a 35-degree apartment in the middle of winter, and water leaks.

“They never returned any e-mails, would never put anything in writing, and I was often forced to scream at them to be heard,” Mr. Seilberger said of Elad Properties. “Getting my apartment in basic working order became a full-time job.”

Mr. Shargian maintains that the developer has not backed off fixing what was broken. “By hiring two general contractors, we’ve paid twice for the same job,” the Elad executive said, “but that is okay because we are responsible for the job. I don’t think there is a tenant who will say we have ignored his requests.”

The developer’s planned conversion of the Plaza threatens the jobs of 900 members of the New York Hotel Trades Council and 200 management employees. Union negotiations with Elad Properties have broken down. The Plaza is scheduled to close April 30.