5 Multi-point Residential Deliveries 5-1 Apartment Communities The following are important U.S. Postal Service guidelines for determining the location and composition of mail receptacles for apartment communities: All new or remodeled apartment houses must install USPS-approved 4C centralized mailbox equipment. There must be at least 1 parcel locker for every 5 mailbox compartments. The Postal Service requires no maximum number of parcel lockers to be installed–only the 1:5 parcel locker/mailbox minimum. Locate mail receptacles and parcel lockers in apartment buildings reasonably close to the entrance in vestibules, hall, or lobbies. The carrier must also be able to serve the boxes without interference from swinging or open doors. Exterior centralized mailboxes may also be an option. The Postal Service may authorize the installation of standard, approved apartment receptacles (4C or CBU) in exterior walls of buildings provided they are not installed directly on the street or a public sidewalk. Provide a canopy for outdoor mailbox installations. The canopy design and location must provide maximum protection from the weather, including driving rain, and provide adequate nighttime lighting.