Certificate of compliance with building control regulations

We are hoping to sell our house which has a very small one-storey extension out the back. It was built by the previous owners and probably dates back to the seventies. My question is, do we need a certificate of compliance with building control regulations in order to sell the house? Or is it exempt due to its age? It is definitely under the 40ft planning permission rule. Thanks in advance.

No you don’t need to get it. It’s only for building work done after march 2014

You should be fine, but there were many changes to planning acts over the years. A trip to the council will help. If there was planning for the extension originally, they will have it! (Recently had to do the same on a relative’s house).

You likely need opinion of compliance with building bye laws (predecessors to Building Control Act 1990) and certificate of exemption from planning permission.
Essentially an Architect/Engineer needs to inspect it and give a view based on a visual inspection.
You should talk to the solicitor you are engaging to sell the house.

Thanks everyone for your replies. I have contacted my solicitor for advice and I’ll report back - I have a feeling we might need to have it inspected.