How to judge worthiness of buidling

make that "should"

before signing the contract, i would have a home inspection done. some old building's wiring is not up to par and has not been upgraded to account for current electricity needs. something else to consider is that if the plumbing has not been updated throughout the building, you'll need to put filters on all of the water lines as they will be providing rust water.

Definitely get the wiring checked. This is something I neglected to do when purchasing my pre-war coop. The result is, that in the summer I cannot run A/C in both the bedroom and main room, which sucks. Plus lightbulbs are always blowing. The coop refuses to pay for the upgrade, and most owners have done it themselves at a cost of $5-6K (plus coop fees for doing work).

yes, if you have old wiring, you will be forced to upgrade it at your expense as soon as you try to do any other electrical work.