The Office of Government Commerce (OGC) have published central Government Department’s Display Energy Certificate (DEC) operational ratings on a building by building level. These can be found at:
www.ogc.gov.uk/government_delivery_display_energy_ certificate_data.asp
It should be noted that the Postal Services Commission shares Hercules house in London with the Cabinet Office and UK Trade and Investment shares Kingsgate house in London with this Department. The Office of Fair Trading occupies Fleetbank house and it is listed under its name.
The table that OGC has published also includes DEC reference numbers for each building. These can be used to view each building’s advisory report on the following website:
https://www.ndepcregister.com/home.html