Indemnity insurance

Have gone sale agreed on a house with a questionable attic conversion. My engineer suggested that the vendors get their own engineer to certify it against their insurance stating that it is structurally sound. I called the EA today who mentioned the engineer that the vendors have hired is 90! I mentioned this to a few family members who mentioned that he’d sign off on anything.

The latter part of that doesn’t bother me too much - I just want the attic conversion insured. But what happens if the engineer passes within the next 10 years? My presumption would be that a dead man can’t have insurance.

Thanks.