As some kind of insurance, if that's the right way to put it, find out who the "developer" is (unless it's the local council, in which case this answer is rendered as no help) and make it known to him, her, them, it, that there is the case of a compliant registered with the said councl. It may be to your advantage if the "problem" is resolved in your favour in order for the project to continue at speed for the cocerned partys, time being money and all that.
Good Luck anyway. I think it's absolutely outblinkinrageous that anyone can just come along one day and say, "Excuse us, we're just going to condem your coservatory to permanent shade."