The NHER was owned and operated by National Energy Services (NES).
The NHER calculates the costs of space and water heating, but adds cooking, lights and appliances to give a comprehensive picture of energy usage in the home.
An average dwelling in England would currently score between 4.5 and 5.5 on the NHER scale.
A gas-heated masonry semi meeting current United Kingdom Part L1 Building Regulations would score approximately NHER 10.
A dwelling with an NHER rating of 20 achieves zero CO2 emissions along with zero net running costs.