Building Energy Experts is the leading building energy auditor, energy retrofit, blow and spray foam insulation, led lighting, and alternative energy specialist for government, commercial, and residential applications since 2008. Building energy experts looks at your building as a complex system, we run a series of diagnostic tests to pinpoint exactly why your building isn’t as energy efficient, healthy, comfortable, and green as it should be. The results of our tests tell us exactly how to improve your building. BPI certified building scientists. Nicor/ Peoples Gas/ North Shore Gas/ ComEd Energy Smart Contractor.