It used to be that the Department of Energy’s principal software tool for energy efficiency modeling in buildings was EnergyPlus, a text-based simulation program for modeling heating, cooling, lighting, ventilating, water, and other types of energy flow in buildings. Then, in April 2008, the DOE’s National Renewable Energy Laboratory released OpenStudio, a free tool that combines the features of EnergyPlus with those of Google SketchUp, the search giant’s drawing interface.

That blend of programs allows architects and builders to sketch 3D drawings of buildings and run energy efficiency simulations for each visual configuration very early in the design process, when implementing changes typically is the least expensive and early insights into building performance are critical.

“Integrating energy analysis into that phase is very important because you can start to reduce energy use well before a building is even in conceptual design,” Nick Long, a NREL engineer who helps develop OpenStudio, said in a recent press release. “Our hope is that by using OpenStudio in design charrettes, users can start throwing away designs at the very beginning of a project, saying: ‘This is not a good design because we’re going to use too much energy,'”

A software developer’s playground

While there is a fair amount of software – some of it requiring the use of special monitoring hardware – being developed to help evaluate the performance of completed buildings (especially homes), tools that help address energy efficiency and building-geometry issues simultaneously, in the conceptual phase of design, can greatly increase the odds a structure will be functionally and aesthetically in top form by the time construction is completed.

Better still, OpenStudio, which was developed using open-source (rather than proprietary) software code, is a perennial candidate for improvements, the NREL notes. Among the enhancements currently being considered: integrating OpenStudio with a daylighting program; linking it to a construction-cost database; and connecting it to the U.S. Green Building Council’s Leadership in Energy and Environmental Design.