When Lawrence J. Simon drove to the Devils Reach subdivision in July to have a look at what he thought would soon be his new home, he was astounded to find a couple living in it. Simon soon learned that the town house in the Occoquan development had been sold twice.

Simon signed a sales contract for the home on Feb. 8, several weeks before Denis C. Buckley and Delores Ann Hancock signed a contract for the same house. Buckley and Hancock's paperwork was processed faster, however, and they signed their final settlement documents at the end of June.

"I had no idea" another contract existed, Buckley said this week. But he added that he also has no doubt that the house legally belongs to him and Hancock.

Simon consulted a lawyer this week about the snafu in the Prince William County development while real estate agents, the developer and a lender blamed each other or county officials for the double sale.

Simon, a divorced father who said he wanted a house with enough room for his two sons when they stayed with him, said he has not decided what he wants to do. He has been offered several other town houses in the development, but he said all are missing aspects that he liked about the house for which he contracted. Sally Merchak, the attorney Simon consulted, said she is studying the case and declined comment.

Several participants in the double sale said the problem was triggered by the way in which lot numbers were assigned to the group of six town houses that includes the one at 1668 Devil Lane, which Simon believed he was buying.

The homes in the complex were built in groups of six, with the lot numbers and addresses running from left to right in all but one of the groups, while houses in the group containing the unit at 1668 were numbered from right to left. Confusion apparently developed as a result of the reversal of the lot numbers.

Simon said real estate sales workers and employes at Ameribanc Savings Bank, the lender for both Simon and Buckley, may have gotten mixed up when they were processing documents.

"I could see making an honest mistake," Simon said. "But why didn't these professionals catch it?"

Lot numbers in a development are assigned by the developer or by an engineer or surveyor working for it, according to Charles McNoldy, director of the Prince William County mapping office. The mapping office assigns addresses on the basis of information it receives from developers, he said.

"I've never heard of anything like this. Some real estate agent really fouled up," McNoldy said.

Assigning lot numbers from right to left "would have been a clerical error. There is no other reason for it to happen," said R.E. Adkins, head of the development company. He said he knew nothing about the reverse numbering or the double sale.

Devils Reach, a 72-unit town house condominium development, has been dogged by problems for months, with many buyers waiting a year or more for their houses. Town & Country Properties Inc. stopped handling sales at the project early in the spring after Simon signed his sales contract, but it continued to help Simon with his paperwork.

"Our position is that we had a contract and we were representing the buyer and seller in good faith," said E.A. Baker Jr., president of Town & Country. Simon was "doing everything right" in the process of buying the house. Baker said his company's attorney is looking into the case and the real estate firm "has offered our resources" to help Simon.

Tom Sennott was the Town & Country agent working with the Devils Reach developer, Occoquan Land Development Corp., when Simon signed his contract. But in mid-February, Sennott moved to House of Brokers, which is now handling sales for Devils Reach, and sold the house again to Buckley and Hancock.

"What happened is that Mr. Sennott sold the house twice," Baker said.

In a telephone interview this week, Sennott first said that Simon's contract was not valid because "all the parties" had not signed an amendment to it, but then said "it was a legal snafu, I guess," caused by the lot numbers.

"In no way is Ameribanc at fault. The developer and the Realtor are totally at fault," an Ameribanc official said. "I believe the Realtor gave us two different numbers" on the loan applications submitted by Simon and by Buckley and Hancock.

Simon's contract called for a sales price of $64,724, but Buckley and Hancock bought the home for $64,174.