SCOTCH PLAINS — The planning board on Monday gave its approval to a site plan to build a three-story apartment building on an empty tract of land at the corner of Grand Street and Forest Road.

The 58,000-square-foot, rectangular- shaped building will be developed by 350 Forest Road LLC and feature 30 units on the second and third floors, five of which will be designated as affordable units. Six will be onebedroom units, 23 will have two bedrooms and one will offer three bedrooms. Among the amenities will be a community room and a rooftop deck. Forty-six parking spaces will be included on the ground floor, including seven electric-vehicle charging stations. Ingress and egress will be via Grand Street and Forest Road. There also will be outdoor open space for residents’ use.

Two contiguous properties — the large grassy lot at the corner of Grand Street and Forest Road adjacent to the library and the smaller lot containing a day-care playground and a garage — will be combined into a single lot for the new building. A section of the latter lot also is occupied by the historic parsonage building that fronts on Park Avenue, but that building is not part of the redevelopment and will be split off into its own lot.

The planning board’s approval sets in motion a sixth significant private development project in and around the downtown. Redevelopment of the former Snuffy’s/ Pantagis property into a grocery store and commuter parking lot is set to begin soon. A new mixeduse building on East Second Street also is in the works, with demolition of the former building completed two weeks ago. Further, a three-story office-retail building at 365 Park Avenue — across the street from the Stage House restaurant — is planned, as is a three-story, 42-unit apartment building on Front Street. Last fall, the Quick-Chek gas station and convenience store opened on the former Jade Isle site at the corner of Terrill Road and East Second Street.