Anoth­er thing you can do – you can work out your degree days and cor­re­late that with your home heat­ing con­sump­tion to see how well your house is per­form­ing insulation-wise. Degree days is the sum of (days * degrees C heat­ing need) over time. It allows you to mean­ing­ful­ly com­pare your ener­gy use from one week to the next when it isn’t the same tem­per­a­ture out­side. There is a good expla­na­tion of it here
http://www.energylens.com/articles/degree-days