Using BEopt in Architecture

BEopt Screen

Building energy optimization is a process that determines how to minimize the energy a building uses, largely for heating and cooling. It turns out there is an app for that. That app is BEopt, and it is a free program developed by the US Department of Energy.
BEopt helps (largely residential) designer choose between hundreds of energy efficiency measures (EEMs) within dozens of categories: Window quantity, location and type; boiler type; building size, massing and orientation; opaque wall and roof thermal performance. All of these options are variables that may or may not contribute to energy efficiency. These variables affect each other, too. Take one EEM and it may affect the performance of another EEM. For instance, no amount of opaque wall insulation can counteract poor windows used in large quantities. But how can opaque wall insulation, window quantity, and window quality work together?
BEopt figures this out by sending design information to an energy analysis program, either DOE2 or EnergyPlus. Along with location-specific weather data, BEopt can sequentially perform several, or even dozens, of year-long simulations for each of the perhaps hundreds of combinations of EEMs under consideration.
Obviously, taking every EEM available under the sun would save the most energy. But most EEMs come with a price tag. When is an EEM too expensive to be sensible? BEopt also contains price information, and the ability to see how EEMs might affect one’s mortgage at the same time it calculates an EEM’s affect on one’s fuel bill. BEopt checks each combination of first cost and energy savings to find a sweet spot- that combination of EEMs and budget frugality that produces the smallest combination of mortgage and fuel bill.
That’s cool, and it answers one of our biggest questions: When does it make sense to incorpate an EEM when first cost and life cycle cost are factors?

Follow Mike Sealander, Maine Licensed Architect:


Principal at Sealander Architects, Ellsworth Maine. Revit guru. Married with 3 children. Avid gardener. Lived in San Francisco for nine years. Master in Architecture from Columbia University Bachelor of arts in religious studies, Wesleyan University. Graduated Staples High School, Westport CT. Hope to spend some time in Hokkaido before all is said and done.