We got planning permission and then went on with a building project, paying out of our savings for the work, no financing was needed for this part.   But.. soon after we started, our main mortgage lender called me saying this was against the terms of our mortgage, we should've informed them about plans etc and that mailing would soon follow.    Of course I'm shaken, stupidly I didn't realise this was going to be a problem, assuming for a second I succeed in my building plan,