Energy Audit FAQ

Answers to the questions building owners and facility managers ask most often before commissioning a commercial energy audit.

What is an energy audit?

An energy audit is a structured assessment of how a building uses energy, where it's being wasted, and what specific, costed opportunities exist to reduce consumption. In the U.S., most commercial energy audits follow ASHRAE Standard 211, which defines three progressive levels, Level 1, 2, and 3, each with a consistent scope so proposals from different firms can actually be compared. See our complete guide to energy audits for more detail.

How often should a commercial building get an energy audit?

Most energy consultants and benchmarking programs recommend a full audit every three to five years, with an annual review of Energy Use Intensity and utility data in between to catch performance drift before the next scheduled audit. A building subject to a mandatory audit ordinance, like NYC's Local Law 87, may have a specific required cycle, often every ten years for a Level 2 audit.

What is the difference between benchmarking and an energy audit?

Benchmarking compares a building's energy performance against similar buildings or its own history, using a tool like ENERGY STAR Portfolio Manager, and is typically a data driven, largely automated process. An energy audit goes further, physically or digitally inspecting a building's systems to identify specific, actionable measures to reduce consumption. Benchmarking is usually the first step that determines whether a deeper audit is worth pursuing. Our article on energy benchmarking covers this in more depth.

How much does a commercial energy audit cost?

Cost depends primarily on which ASHRAE level is performed. Level 1 audits typically run $0.05 to $0.10 per square foot, Level 2 audits run $0.10 to $0.30 per square foot, and Level 3 investment grade audits run $0.25 to $0.50 per square foot or more. A full breakdown is available in our article on commercial energy audit cost.

What is a digital energy audit?

A digital energy audit collects the same information a traditional audit requires, but does so remotely, using drone thermal imaging, wireless sensors, satellite imagery, and remote utility data access through remote assessment, rather than relying primarily on an in person site visit. It's especially effective for fast, low cost screening across a large portfolio. See our guide to digital energy audits for more.

Which ASHRAE audit level does my building need?

It depends on the decision the audit needs to support. Level 1 fits portfolio screening, due diligence, or a basic compliance requirement. Level 2 fits most mandatory audit ordinances and general capital planning. Level 3 fits major capital commitments and energy performance contracts, where the savings guarantee needs construction grade precision behind it. Many organizations move through the levels in sequence rather than jumping straight to the most detailed option.

Do I need an energy audit if my building is already benchmarked?

Benchmarking tells you how a building compares to others, it doesn't tell you why, or what specific measures would close the gap. A well benchmarked building that's still underperforming its peers is exactly the kind of building an audit is meant to diagnose.

Is an energy audit required by law?

It depends on location. Over 40 U.S. jurisdictions now require ASHRAE standard audits for large commercial buildings as part of a benchmarking or building performance ordinance, including New York City, Boston, Atlanta, San Francisco, and Seattle, with size thresholds and required audit levels varying by jurisdiction. Our article on Building Performance Standards covers the major U.S. mandates in detail.

How much can I expect to save from an energy audit?

According to Department of Energy data, buildings that implement audit recommendations typically achieve 10% to 30% energy savings, though the actual figure depends heavily on how inefficient the building was to begin with and how much of the recommended work is actually implemented afterward.