Keywords: sustainable buildings, building performance, energy conservation, building siting, water conservation, materials selection, indoor environmental quality, green buildings, building costs, energy consumption, water consumption, materials recycling, indoor pollution, public transport, occupant comfort, performance evaluation
Do certified sustainable buildings perform better than similar conventional buildings?
The aim of this study is to assess the performance of sustainable buildings. Its objective is to compare certified green buildings with similar in location, size, age and function conventional buildings by testing hypotheses that green buildings perform better than conventional ones. Objective data including building costs, energy and water consumption, material recycling, indoor pollution sources and proximity to public transportation and subjective information on occupant comfort, recycling systems and indoor pollution conditions were gathered by interviews of occupants and engineers of 20 buildings, the 10 certified sustainable buildings in the study area and 10 conventional buildings. Criteria for sustainable performance are (1) the five LEED certification components (2) 39 sustainability performance characteristics or attributes, at least seven within each component. Analyses with non-parametric tests indicate that there is no statistically significant difference between sustainable and conventional buildings in 49% of the attributes. Conventional buildings perform statistically better in 10% of the attributes examined. Green buildings perform better than conventional buildings for the remaining 39% of building performance attributes. We conclude that labelling buildings as sustainable, making use of design and construction plans does not guarantee sustainable building performance and recommend periodic performance evaluation of certified buildings.