SWAMPSCOTT – The developer whose condominium project at the Greenwood Avenue School was blocked by neighbors has sued Swampscott for breach of a purchase and sale agreement after the town allegedly refused to sell the land for affordable housing.Groom Construction, of Salem, filed a civil suit in Essex Superior Court in early March, the latest in a flurry of lawsuits and zoning changes concerning a property that has been vacant since 2007.The circa-1893 Greenwood Avenue School served for years as the town’s high school and then middle school, but was shuttered in 2007 when the new high school was built on Essex Street. Since that time, the building has remained vacant.The town wrote development guidelines for the site in 2008 and offered the property for sale the following year. But selectmen rejected a proposal for an elder-living facility at the site. The town rejected other proposals after putting the site back on the market in 2010. The town subsequently removed historical restrictions on the site and tweaked development guidelines to put the property up for sale a third time in 2011.Selectmen voted in October 2011 to accept a proposal from Groom to raze the school and build a single, four-story building, including 41 residential units.The town entered into a purchase and sale agreement with Groom following the Swampscott Zoning Board of Appeals January 2013 approval of the proposal, according to the suit.But 13 neighbors had already filed a lawsuit in Massachusetts Land Court arguing that the planned development district constituted illegal spot zoning because it singled out the property for development solely with the objective of making money for the town.”I find that the town’s objectives in rezoning the Greenwood parcel were initially historic preservation and generating revenue for the town. When historic preservation affected revenue, however, this goal was discarded and the town’s objectives narrowed to one: the maximization of revenue from the parcel’s sale and future tax receipts,” Judge Keith C. Long wrote in a March 4, 2014 decision in favor of the neighbors.The suit filed on behalf of Groom does not mention this decision. But it notes that the town and Groom had extended the terms of the purchase and sale agreement to Dec. 30, 2014.Town Administrator Thomas Younger said the board of selectmen initially agreed to appeal the Land Court ruling, but voted 3-1 in June to withdraw that appeal.Groom sent a Nov. 6 letter to the town stating that it wanted to build a project at the site under the state’s 40B guidelines. This law allows expedited zoning review and eases certain zoning restrictions for development containing a certain percentage of affordable housing in communities where less than 10 percent of the housing is considered affordable by state guidelines. As of Dec. 5, 2014, 3.7 percent of housing in Swampscott is considered affordable, according to the state’s inventory.The town wrote a Dec. 14 letter to Groom saying it would not sell the property, according to the suit, however, and reiterated this in a Dec. 16 letter.Town Planner Pete Kane said that the planning department did not receive any proposals for a 40B development.Groom requests that it be awarded an unspecified amount in damages, that the town sell the property to Groom, and that the town not be allowed to sell the property to a third party while litigation is pending.An attorney representing Groom did not return calls for comment.