The Green Roof Energy Calculator is an online tool that allows users to compare the annual energy performance of a building with a vegetative green roof to the same building with either a dark roof or a white roof.
Simulations are available for new construction (ASHRAE 90.1-2004) and old construction (pre-ASHRAE 90.1-2004) office and residential buildings driven by typical precipitation and weather data. Representation of an irrigation schedule is optional.
The Green Roof Energy Calculator was developed through a collaboration led by Dr. David Sailor (while he was on the faculty of Portland State University), along with researchers at the University of Toronto, and Green Roofs for Healthy Cities. The effort was funded by the US Green Building Council with additional financial and in-kind support from University of Toronto, Portland State University, Green Roofs for Healthy Cities, and Environment Canada.