An Alteration Type 1 (Alt1) permit is required for any major construction that affects the use, egress or occupancy of the space, and results in the issuance of a new or amended Certificate of Occupancy (CO). Examples: Converting a commercial building or space to residential. Vertical enlargements (adding floors)
Level 2 alterations include the reconfiguration of space, the addition or elimination of any door or window, the reconfiguration or extension of any system, or the installation of any additional equipment.
Level 3 Alteration is level 2 alterations where the work area exceeds 50% of the aggregate area of the building (total floors area). Work area is defined as that portion or portions of a building consisting of all reconfigured spaces, as indicated in the construction documents.