I hate it when I see energy diagrams like this and it reads in the red, so I thought I'd explain How To Read an Energy Efficiency Diagram.
The truth is though, most people haven’t a clue what this diagram means. They all assume G is bad, but they don’t actually know why it’s bad.
Starting simply, this is an Energy Efficiency Diagram. The higher the ratings on this graph, the lower fuel bills are likely to be.
Your homes energy rating is measured in SAP points (it’s all to do with the amount of carbon dioxide your home produces).