Vote Early, Vote Often: Using ENERGY-10 to Design Low-Energy Buildings

It is a generally accepted maxim that the greatest opportunity to impact energy use in building design (in both new and existing construction) occurs early on in the design or retrofit process. While building energy simulation can be an extremely useful tool to help identify of viable alternatives, the difficulty of use and complexity of many energy simulation tools often negates their effectiveness and acceptance in early-stage design activities. The ENERGY-10 program was conceived to overcome these hurdles by providing a framework to easily articulate and compare many energy alternatives long before detailed design work has begun (facetiously, the watchwords are "Vote Early, Vote Often"). Many model development tasks are automated including generic building take-offs, equipment sizing and definition of energy efficiency strategy (EES) alternatives. Tasks that previously took hours and days have been shortened to minutes. Evaluations are based on hour-by-hour simulations of both daylighting and thermal performance. An extensive set of graphical outputs greatly aids the process of assimilating and understanding the results. This paper describes the Energy-10 program and lessons learned in applying this tool, over the past five years, to the design of low-energy buildings.