The Rehabilitation Subcode, N.J.A.C. 5:23-6.1, et seq. establishes the construction code requirements for proposed construction in existing buildings. This Subcode only specifies the requirements for work within an existing building. Additions to existing buildings must comply with current code requirements. The Rehabilitation Subcodes categorizes work in the following manner:
Repair work may or may not require a permit. Those requirements are established elsewhere in the code. Generally, repair work is replacement of existing materials or components in kind, but certain materials are prohibited.
Renovation means the removal and replacement of existing interior or exterior finish, trim, doors, windows or other materials with new materials that serve the same purpose but do not change the configuration of the space.
Alteration means the rearrangement of any space by the construction of walls or partitions, a change in ceiling height, the addition or removal of doors or windows, the extension or rearrangement of any system, the installation of any additional equipment or fixtures or any work that reduces the load-bearing capacity of a structural member.
Reconstruction means any project where the extent and nature of the work is such that the work area cannot be occupied while the work is in progress and where a new certificate of occupancy is required before the work area can be reoccupied. A reconstruction project may include repair, renovation and alteration components.
Work in an existing structure may require that an effort be made to bring the building into compliance with the Barrier-Free Subcode. Improvements that increase accessibility for the disabled may be required. Generally the value of the required expenditure for these improvements is capped at 20% of the value of the other work proposed.