Those types of inspections can be done between tenants such as when one moves out and before the new one moves in. Tenants can be notified of the request to inspect, and give or not give permission..or not. If a landlord has a rep for being a slum lord.
Not here nor I think in most cities in the NE. Besides habitability inspections being required for all apts (except LL families) when new tenants move in, regardless of their consent, every 5 years habitability inspections are required for all apts (except LL families) regardless of the rep of the LL. Who are charged for the inspection. Tenants are notified but cannot refuse or police will be used. And it is even illegal for an owner replace his steps on a 3 decker himself. He/she is supposed to hire a contractor who is to pull a permit. My neighbor did so, replacing about 6 large cement steps and the inspector failed it because one step was about an 1.5'' different from another. Broke it down and did it again. Inspector never came back. Thank God.