Thank you for your response, This is what we have it’s a fully insulated lean-to (see photo) Made a big mistake by going to the council especially when we could have got an indemnity insurance but followed advice from estate agent to satisfy the buyer. In hind sight should have gone through the solicitors. We have now put in double glazed external doors between the house and the lean-to.
Hopefully having a kitchen in the conservatory is ok?