we are in the process of buying an 18c farmhouse in Basse Normandy with a tin roof. We have just had an energy survey through which says the 'consommation en energie' is 576 kWh ep/m2.an (whatever that is!) which doesn't look good. Can anyone advise on what we should be looking for, or questions to as the vendor. We are going to ask them if we can see some of their bills.