Other considerations would be updated electrical wiring, (existing may not meet code for commercial), ADA compliance in bathrooms and entrances, firecoding between different zoning use areas (between some types of retail and offices for eg), noise restrictions may require acoustical changes, floor load considerations, emergency lighting and exit signs, sprinkler systems may be required, smoke detectors and annunciators, separate alarms systems for each unit, accessibility restrictions between different units may hamper emergency access and egress, and energy upgrades to meet audit compliance. Also consider updated communications wiring.
Anything else? I'm sure we can find more. :shutup: