Simulation-Based Comparative Study on Energy Efficiency Criteria for LEED and BREEAM Systems

Abstract Energy efficiency is regarded as one of the important elements of green building. Every Green Building Rating (GBR) system puts forward a set of criteria for energy efficiency and it is different for each system. A comparative study is done to distinguish between two GBR systems practiced worldwide-LEED and BREEAM, first on the criteria for energy efficiency and secondly on how efficient and effective each system in energy performance improvement. Building energy simulation tool, eQuest is used to obtain annual energy consumption of a case study multi-family dwelling residential building for its various design options. Different design cases were formulated by changing design parameters and the simulation results thus obtained are used for evaluating the performance improvement for energy, calculated as per the criteria for each system. This study primarily looks for the combinations which grab total achievable credits in energy efficiency for a particular system. For LEED, it was found that renewable energy allocation alone has the greater influence in achieving higher credits. For BREEAM, there requires specifically a considerable decrease in HVAC load which can be brought by the means of more natural ventilation or by adopting passive cooling techniques. BREEAM was also found more effective in reflecting any kind of improvement made in terms of awarding credits.