Beginning in 1964-68, as 40-year covenants expired on individual properties, some homeowners overtook garden spaces by installing driveways or fencing off portions of the open courts to enlarge their private yards. Still, the great majority of neighbors adhered to the original ideal of open space, in two homeowners associations by renewing covenants and in others by tacit agreements to maintain the common courts. Responding to the loss of protective covenants, New York City amended its Zoning Resolution in 1974 to name Sunnyside Gardens a Special Planned Community Preservation District. This law addressed the need to limit the size of buildings and protect open space. Fencing of open commons, building enlargements, sheds, curb cuts and parking in yards were all effectively curtailed by requiring a Special Permit from the City Planning Commission.
Sunnyside Gardens, including Phipps Garden Apartments, was added to the National Register of Historic Places in 1984. In 1991, the neighborhood was named a National Planning Landmark. Beyond these honors, designation as a New York City Historic District in 2007 empowers the New York City Landmarks Preservation Commission (LPC) to regulate the exteriors of buildings.