The Norwalk Planning and Zoning Commission is scheduled to hold a virtual public hearing at 6 p.m. Thursday for a proposed 1,300-unit mixed-use residential development. Building & Land Technology, a Stamford-based firm responsible for more than a dozen similar commercial and residential properties across Fairfield County, is aiming to build the apartments on largely vacant swath of land west of Glover Avenue. Dubbed “North Seven,” the proposed development would be sandwiched between the Danbury Line spur of Metro-North and the Route 7 highway extension. BLT is seeking the commission’s approval to amend zoning rules and to create a master plan to guide North Seven’s overall design and development. The firm has said it intends to construct the complex in multiple phases over several years.