No building works completion certificate

[cashmerecardigans]

We've just discovered that the single storey extension of the house we are buying doesn't have a completion certificate. The builder who did the work, which is about 5 years ago, seems to no longer be contactable.
We don't really want to go down the indemnity insurance route, so can any one advise on what options we have. I'd rather know it has been done properly, so really would want to get it signed off if at all possible. Does anyone have experience and can advise on potential costs and also how long it might take to get sorted out?
Thanks

My parents had this 2 weeks ago. Called council, who said it happens all the time because builders forget and move to new job. The assessor came out the next day and signed it off (their work was the removal of 2 chimneys about 10 years ago!). They exchanged contracts yesterday. Good luck!

This is for your seller to sort out, not you. They need a regularisation certificate, which is what pp is talking about. The seller will have to pay a fee for this.

Thanks for your responses. Sounds like it's only the final inspection that was missing, so hoping it's going to be straightforward to resolve.