For decades, developers have sought approval to build retail and residential buildings on a grassy property in southeast Plano and been denied. On Monday, those hopes were bolstered. The Plano Planning and Zoning Commission on Monday unanimously supported a rezoning request and accompanying site plan that could allow retail, office and retirement housing buildings to be constructed on a property north of 14th Street, about 900 feet east of Shiloh Road. The proposal still requires approval from Plano City Council before the property owner can move forward with the project. Last year, the commission had denied a zoning change request that would have allowed single-family residences and retail uses on the property. Efforts to rezone the property date back to at least 1985, when the City Council determined the property was more suited for its current industrial zoning because of its proximity to a sewer treatment plant to the north, according to documents prepared for zoning commissioners by city staff. The vote for the rezoning request was 6 in favor, none against.