Using display energy certificates to quantify public sector office energy consumption

The influence of internal and external characteristics on energy use in the public sector office stock in England and Wales is explored using a database of 2600 Display Energy Certificates (DECs) combined with other sources of disaggregated office information. The DEC office benchmarks are shown to match the median fossil thermal and electrical consumptions well. Analyses of heating, ventilation and air-conditioning (HVAC), size, occupancy density, building age, location and rateable value are considered. While newer offices are shown to have lower typical fossil-thermal consumption than older offices, this is counterbalanced by higher electrical consumption, resulting in higher typical CO2 emissions. This has implications for the UK's emissions reduction targets for 2050, indicating that while building regulations that focus on thermal performance have been successful, a focus on electrical consumption (both regulated and unregulated) is key. The results are also compared with existing benchmarks for all UK offices, splitting the sample into four generic types, and compared with a similar smaller study of private offices. This indicates that public offices typically used less energy than the general benchmarks had previously predicted, particularly for prestige offices.