The rating is the second-worst a building can receive, and could cause embarrassment for the CLG, since it is the Government department charged with reducing the carbon emissions of public buildings through the energy efficiency initiative.
A CLG spokesman dismissed the suggestion. He said: “Even though the headquarters is open to the public, Eland House is not a public building and so is under no obligation to display the certificate.
“However, as the department with lead responsibility for DECs, CLG made it a priority to get a certificate and the DEC has been displayed in its reception since July.”
He said one of the reasons why the building received such a low rating was because “…it is now almost 15 years old, so some of the equipment is ageing”.
Eland House was designed in the 1990s and opened for business in 1998.
He added: “Our rating for Eland House tells us we must clearly do better to make a difference to our energy performance.
“We are now acting on recommendations from our Advisory Report to help us improve future ratings.
“Some of the carbon reduction initiatives being considered include improving the air conditioning, installing a combined heat and power unit, the introduction of automated meter readings and voltage optimisation.
“This activity should take Eland House up to an E rating, and towards a target D operational rating.”
The Department said it was confident it could improve on this year’s energy rating performance as it was able to reduce its gas and electricity use by 37 per cent and 22 per cent respectively, compared with the previous year.
From October this year all public buildings over 1,000 s qm must prominently display their DEC.