ASHRAE Energy Audits: An Overview

 American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) Standard 211-2018 for Commercial Building Energy Audits replaces the “best practices” or “green book” that provided a basic framework for sustainable practices. 
The most significant change for the industry is that 2011-2018 establishes industry standards, while the green book, Procedures for Commercial Building Energy Audits, included best practice guidelines. 


Benefits of an ASHRAE Energy Audit

Builders stand to gain many benefits from going through the ASHRAE energy audit process. While the primary goal of an energy audit is to improve energy efficiency and reduce utility costs, there are several additional benefits:

  • Helping to secure LEED certification
  • Reducing maintenance costs
  • Identifying ways to improve energy consumption through small changes
  • Lower energy bills
  • Less downtime
  • Improved air quality, safety, and comfort
  • Fewer occupant complaints and maintenance calls
  • A reduced carbon footprint


The ASHRAE Energy Auditing Process

ASHRAE 211-2018 details the required steps for performing ASHRAE Levels 1, 2, and 3 energy audits and establishes standardized industry practices and reporting requirements. 

All three audit levels require a “qualified energy auditor” to conduct the analysis. ASHRAE 211-2018 identifies these professionals as energy solutions professionals who:

  • Assess building systems and site conditions
  • Analyze and evaluate equipment and energy use
  • Recommends strategies to optimize building resource use
  • Have completed five commercial (non-residential) building energy audits within the past three years or a cumulative completion of ten or more commercial building energy audit

Qualified energy auditors must hold one of these credentials:

  • Certification from a credentialing program approved by the U.S. Department of Energy Better Building Workforce Guidelines for Building Energy
  • License as a professional engineer or contractor specifically approved by the authority having jurisdiction (AHJ) to conduct energy audits
  • Approval as qualified by the AHJ


Level 1 Energy Audit: Walk-Through Analysis 

Level 1 ASHRAE energy audits are basic. The standard specifies that Level 1 energy efficiency recommendations are qualitative—auditors assign a high, medium, or low rating to measure savings, cost, and priority. The green book required specific dollar amounts. 

To be considered complete, a Level 1 analysis must quantify historical energy consumption and provide a site benchmark. Qualified energy auditors should:

  1. Review historical utility and onsite generation data (5.3.1), including historical billing data (
  2. Review rate structure (5.3.2) (for example, basic service charge, power factor changes, and consumption charges).
  3. Conduct a facility site survey (5.3.3), including a site survey ( and identify specific energy factors, including Operations and Maintenance problems and needs (

Every Leadership in Energy & Environmental Design Existing Building Operations and Maintenance (LEED EB: O&M) project requires an ASHRAE Level I energy audit. 


Level 2 Energy Audit: Energy Survey and Analysis 

Level 2 ASHRAE energy audits focus on quality control. These audits must “ follow, and consider the findings of a Level 1 audit. If no separate Level 1 audit has been conducted, the Level 2 audit shall comply with all of the procedural requirements for a Level 1 audit,” according to ASHRAE 211-2018. 
Level 2 audits answer the question, “How do my savings numbers compare to the base case energy use?” These audits require owners to demonstrate they understand the building and site energy costs. Qualified energy auditors should:

  1. Determine energy cost component breakdown(5.4.1).
  2. A facility site survey (5.4.2) conducted by a “qualified energy auditor as part of a walkthrough survey of the building.”
  3. Review current O&M procedures (5.4.3), including current and past issues.
  4. Determine key operating parameters (5.4.4), including operating set points and schedules, equipment efficiencies, and qualitative assessments of several specific elements.
  5. Conduct end-use breakdown (5.4.5) of “each system or unit of equipment that uses energy.”
  6. List potential energy savings opportunities (5.4.6).
  7. Calculate energy savings (5.4.7) for “key energy uses that will be impacted by the improvement, by energy source type (electricity, gas, etc.).”
  8. Examine hazard material abatement needs (5.4.8).
  9. Conduct an economic analysis (5.4.9).
  10. Conduct a quality assurance review (5.4.10) 


Level 3 Audit Overview: Detailed Analysis of Capital-Intensive Modifications

Level 3 audits are the most stringent and detailed, requiring components like a schematic installation diagram. Level 3 audits provide additional quality controls aimed at ensuring the proposed project and its components will fit the facility’s specific physical requirements. These audits are suitable for complex commercial and industrial buildings.
ASHRAE 211-2018 (5.5.1) establishes that Level 3 audits require higher technical rigour and savings estimates based on actual, measured values or hourly simulations. Level 3 audits also require a simplified analysis of variance in key assumptions. 
Ideally, this analysis will help the owner evaluate cost justifications. The steps required are inclusive of Level 2 steps, but auditors need to conduct a more in-depth analysis and document more detailed information. 


Finding the Right Quality Energy Auditor for your Building

As you begin to plan for your ASHRAE audit, take care to select a qualified energy auditor with a working understanding of the energy sector. Energy systems engineers are often well-suited for this task. An analysis conducted by an engineer ensures a process that includes:

  • Adherence to professional industry standards
  • Correctly conducted methodology
  • An objective review of benefits and costs

Learn more about the advantages of partnering with Switch Engineering for your ASHRAE energy audit. We can help you determine when and how to get started!