A CIBSE study has found that the benchmark figures used in Display Energy Certificates (DEC) are fit-for-purpose, with 94 per cent of the buildings studied showing a good correlation between the benchmarks and the actual operational ratings.
The CIBSE has published the results of a study of the first 45,000 DECs lodged on the Landmark register from October 2008 to mid-February 2010. The study focused on Operational Ratings in order to assess the applicability of the CIBSE benchmarks, and to provide evidence to the Department of Communities and Local Government for any changes to the benchmarks or allowances.
The UCL Energy Institute worked with Phil Jones of Building Energy Solutions, Robert Cohen of Camco and Bill Bordass of the Usable Buildings Trust to undertake the detailed review.
The results show that the benchmarking system works well for those building categories most commonly found in the database. Schools account for 15,335 DECs, equivalent to 52 per cent of the total. The median school DEC Grade is within 2 per cent of the benchmark.
For the 3,230 office buildings (11 per cent of the total), the median is almost exactly at the D/E boundary, which matches expectation.
The benchmarks work well for clinics, hospitals and emergency service buildings, while the benchmarks for entertainment halls and theatres, dry sports and leisure facilities appear to be too generous.
Benchmarks for laboratories and operating theatres and for workshops need review. Their special energy uses equipment generally leads to high loads.
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