ALTERATION. Any construction or renovation to an existing structure other than repair or addition. [DSA-AC]
A change, addition or modification in construction, change in occupancy or use, or structural repair to an existing building or facility.
Alterations include, but are not limited to, remodeling, renovation, rehabilitation, reconstruction, historic restoration, resurfacing of circulation paths or vehicular ways, changes or rearrangement of the structural parts or elements, and changes or rearrangement in the plan configuration of walls and full-height partitions. Normal maintenance, reroofing, painting or wallpapering, or changes to mechanical and electrical systems are not alterations unless they affect the usability of the building or facility.
California Building Code Ch. 2 Section 202