One young Island family's dream of building an affordable home on Chappaquiddick hit a roadblock last month when a Marblehead couple that owns a summer home next door purchased the land out from underneath them.

Joe Spagnuolo and his wife Cheryl Herrick have been trying for over a year to complete a deal allowing them to purchase a one-acre lot on Sandy Road. The couple were among three groups of residents who received a special permit from the town zoning board of appeals in August of 2005 allowing them to build on the substandard lots.

Minimum zoning on Chappaquiddick is three acres, but building on substandard lots is allowed by special permit for qualified applicants under a special town zoning bylaw. Edgartown voters adopted the bylaw at the 2001 annual town meeting to help create more housing opportunities for town residents who could not afford lots at market rates.

After receiving special permits from the board of appeals in August of 2005, Mr. Spagnuolo and Ms. Herrick, along with Andrea DelloRusso and her husband Luke Riordan, and Clinton Fisher were given approval to build on the substandard lots on Sandy Road.

The one-acre lots were carved out in a 1970s subdivision plan that predated three-acre zoning by two weeks. A group of abutters sued the town in the fall of 2005 to block the affordable homesites. The litigation has delayed the real estate closings on the three homesites for over a year.

Mr. Spagnuolo and Ms. Herrick had previously held a purchase and sale agreement with Juanita B. Vickers of Melbourne, Fla., to buy their one-acre parcel for $40,000. The agreement expired in September.

Ms. Vickers has now sold the lot to Robert and Cheryl Finkelstein, who are abutters living on another substandard lot and plaintiffs in the lawsuit. (The other plaintiffs are George Mellendick, James Williams, William O'Connell, Paul Wales, Frank and Karen Gazarian, Cornelia Dean and Lionel Spiro.)

According to a quitclaim deed filed on Sept. 29 with the Dukes County Registry of Deeds, the Finkelsteins paid Ms. Vickers $287,900 for the lot that Mr. Spagnuolo had planned to buy for $40,000.

Ms. Vickers offered Mr. Spagnuolo and Ms. Herrick another parcel she owned on Chappaquiddick for the same price of $40,000, but the substandard lot was not grandfathered and was therefore unbuildable.

The couple appeared before the board of appeals in late November seeking a variance, but were unsuccessful. Following public comment at the hearing, board chairman Martin (Skip) Tomassian questioned why the board was considering the creation of a new affordable lot after Mr. Spagnuolo and his wife had been granted one in 2005.

Mr. Tomassian also criticized the neighbors who are trying to block three affordable housing lots - at cost to the town.

Mr. Spagnuolo and Ms. Herrick have since been offered a third lot from the Vickers family at the price of $40,000, and are scheduled to go before the board of appeals again on Jan. 24 seeking permission to build on another substandard 2.1-acre lot.

Meanwhile, the ten plaintiffs in the lawsuit have lost two key rounds in court, with pointed comments from a judge about the lack of merits in the case. They are now appealing the matter to a higher court.

Town attorney Ronald H. Rappaport said he was disappointed Mr. Spagnuolo and Ms. Herrick lost the opportunity to build on the lot they initially had under sale agreement with Mrs. Vickers, and he too had sharp words for the abutters who continue to press their case in court.

"It should not have been this difficult for these people to buy this lot and move into their home. If there was a hall of shame for this kind of frivolous litigation these people would be right there," Mr. Rappaport said.