Which rating indicates the lowest energy efficiency?

The G rating signifies the lowest level of energy efficiency in the context of energy performance ratings. Energy ratings typically follow a scale that ranges from A to G, with A representing the highest efficiency and G representing the lowest.

The G rating indicates that a building or appliance is not performing well in terms of energy consumption compared to others in the same category. This means that it is likely to incur higher running costs due to inefficient use of energy, which might also lead to a larger environmental impact. Understanding this rating system enables individuals and organizations to make informed decisions about energy use, efficiency upgrades, and necessary improvements in building services engineering.