MELBOURNE — Holiday Builders, the Florida homebuilder that constructs houses in Sebastian Highlands and the Spirit of Sebastian, has been acquired by Stanley Martin Homes. Holiday Builders is now a wholly owned subsidiary of Stanley Martin Homes, ranked the 18th-largest homebuilder in the nation. “We are proud of the foundation Holiday Builders has built across Florida and are excited to join the Stanley Martin Homes organization,” said Bruce Assam, president and chief executive officer of Holiday Builders. Stanley Martin Homes, based in Reston, Virginia, was established in 1966. In Indian River County, Holiday Builders continues to build in Sebastian Highlands and the Spirit of Sebastian, the county’s first agrihood.