Refurbishing old buildings

My nephew has been investing in real estate and starting to refurbish old buildings.
Remember if this is your forte, if multiple tenants are moving in check beyond the walls, ceilings, plumbing, electricity, etc., also check for conduit runs as well as conduit paths into the structure from the feed source/property line/manhole. When buildings are sold and tenants leave for refurbishing/renovation efforts, conduits are forgotten. Therefore conduit may be packed with old wire and cable, not allowing additional space for any telephone or electrical wiring to replace the long forgotten cable. Tenants do not remove these components, in fact often times not only are conduits filled, sometimes equipment and wiring remains long after the tenants have left. Replacing these conduits after renovation will be expensive so the best opportunity is knowing what to look for on the front end of new refurbishing construction.