Simon wrote:
I am buying a property, when the seller is unable to provide either building
regs, or a fensa cert for windows installed after April 2002.

I may be "happy" with the windows, however this question will undountable
come back to me when the property is sold by me, unless I replace the
windows in the meantime.

What is the remedy?

You are most likely to find someone, like yourself who would be happy,
and will have the common sense to realise that they are OK.

Also it will such a while since they were fitted, so that there will be
no probelms or interest from building control.

dg