nothing was mentioned on the survey when I purchased the
house (I used the banks full survey option, cost me £1500 and they
were rubbish!). Think it will have to go down to experience!

If you just had a survey - even a full one - a surveyor will carry it
out. They are looking at the structure of the building and the result
usually explicitly says that it is not an electrical survey.

I gave up having electrical surveys after just one as it seemed to be
more concerned with the fact that the house did not fully meet the
_current_ wiring regulations and had some 45 degree cable runs and did
not spot the spur from spur from spur set up in one room. I was more
worried that there might be something dangerous in place.

dan