Energy consumption in conventional, energy-retrofitted and green LEED Toronto schools

Green buildings have been marketed as the economical, energy-efficient alternative to conventional buildings. This is despite little existing empirical evidence to prove their energy efficiency, especially in Canada. To overcome this limitation, the electricity and gas consumption quantities and costs of a sample of 10 conventional, 20 energy-retrofitted and three green Toronto schools following the Leadership in Energy and Environmental Design Rating (LEED) System for New Construction were analysed in this study. The analysis conducted over eight years for conventional and energy-retrofitted schools, and since their inception for green schools, showed surprisingly that energy-retrofitted and green schools spent 37% more on electricity than conventional schools. Nevertheless, green schools spent 56% and 41% less on gas than conventional and energy-retrofitted schools respectively. Their total energy costs were also 28% lower than conventional and energy-retrofitted schools. Nevertheless, these savings do not always justify their construction cost premiums. The study showed that more research was needed to overcome the scarcity of data on green buildings in Canada. There was a need to focus on analysing more green buildings, of various types, and over longer study periods in order to better understand why some green buildings do not live up to expectations.