I don't see anything wrong with the houses/flats/apartments posted, externally anyway.
I agree that if the place is visibly unclean or untidy inside then the provider probably does not care about her services, and therefore would be a good choice to avoid, but to avoid a prostitute just because she is working from a slightly run-down property (council or otherwise) seems insane.
'house' / 'flat' / 'apartment'
'escort' / 'courtesan' / 'hooker'
Same difference as far as I can see. We'd all love a mansion (or whatever our own version of a mansion is) but I don't think a prostitute's accommodation/working premises have anything to do with her standard of service or professionalism.
If I rented out one of these so called 'luxury apartments' to work from, my customers would be paying for it in raised rates, or I would be one frazzled prostitute from working to pay for the premises!
If it's clean, relatively tidy and secure , and fit for purpose I'd say a good bet.