In article ,
said...
no bank/mortgage company will touch a
property which does not have a Certificate of Occupancy

When the house was originally built, it got a certificate of occupancy. That
is quite enough.

If he/she won't, walk away.
Nonsense. People buy these houses every day.

Likewise, houses with a CO and neglect can be much worse off than one that
was added onto by and good DIY-er. Inspect, inspect, inspect.