Heating, ventilation, and air conditioning (HVAC) systems account for a substantial share of commercial building energy use, but many property managers have limited visibility into where those energy dollars go. When costs rise without clear changes in occupancy, rates, or equipment, a building energy audit may provide the structured look needed to find answers.
For property managers and facilities directors, an audit may produce a documented picture of how a building uses energy, where inefficiencies exist, and which improvements may offer the best return. Many cities now require audits for commercial buildings above a certain size, making them both a practical planning tool and a compliance obligation.
Whether the motivation is operational planning or regulatory compliance, preparation may affect how useful the final report turns out to be. This guide covers what a building energy audit includes, the three standard audit levels, a practical preparation checklist, and what to expect from the final report.
Key takeaways: preparing for a building energy audit
Understanding audit scope and preparation considerations helps property managers and facilities directors get the most value from a building energy audit.
What to know before scheduling
- The American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) Standard 211 defines three audit levels with distinct scope, cost, and deliverables.
- Heating, ventilation, air conditioning, and refrigeration (HVAC&R) systems represent a major share of commercial building site energy use, making them a primary focus in most audits.
- Multiple U.S. cities now mandate energy audits or benchmarking for commercial buildings above size thresholds.
How to prepare effectively
- Pre-audit preparation requires at minimum 12 months of utility data for all fuel types, building drawings, and equipment records.
- Operations staff availability on audit day may affect the auditor’s ability to access systems and collect data. .
- Preparation typically begins eight or more weeks before the audit, with document collection starting first.
Contact Us to speak with a qualified expert about building energy audit services.
Scope of a building energy audit
Most commercial energy audits follow the same core structure, with ASHRAE Standard 211 defining the minimum scope requirements.
That scope typically includes the following building systems:
- HVAC
- Lighting
- Building envelope (walls, windows, roof, insulation)
- Building automation and control systems (BAS)
- Domestic hot water
- Elevators and escalators
- Plug loads (office equipment, computers, appliances)
- Food preparation, laundries, and pools where applicable
How thoroughly auditors evaluate each system depends on the audit level. Regardless of level, the baseline analysis includes a calculation of the building’s Energy Use Intensity (EUI), which measures annual energy consumption per square foot and provides a basis for comparing performance against similar properties. That EUI calculation and the broader scope of the audit are both grounded in ASHRAE Standard 211, though mandatory requirements vary by city and jurisdiction.
Benefits of a building energy audit
Building energy audits may help identify cost-saving opportunities, support regulatory compliance, and inform capital planning decisions. They are most useful when tied to a specific need:
- Cost reduction. Rising or unexplained energy costs are one of the most common drivers for commissioning an audit. HVAC&R systems are often the primary focus, since they account for a substantial share of commercial building energy use.
- Regulatory compliance. Mandatory audit programs, such as San Francisco’s Existing Commercial Buildings Ordinance, illustrate how documented findings may contribute to measurable efficiency gains alongside compliance requirements.
- Capital planning. Audits typically establish a building’s Energy Use Intensity (EUI), a benchmark that allows owners to compare performance against similar properties, set measurable goals, and track progress over time.
- Certification support. Audit findings can support programs such as Building Owners and Managers Association (BOMA) 360, which awards points toward certification for documented energy management activities, including audits.
Three levels of building energy audits
Which of those benefits an audit delivers, and how fully, often depends on the level selected. ASHRAE Standard 211 defines three audit levels, each building on the one before it with greater depth of analysis and reporting. The range runs from a quick walk-through to a full investment-grade analysis, with minimum scope requirements for each level grounded in the standard.
Level 1: Walk-through survey
A Level 1 audit is an initial screen. It involves a brief facility walk-through, a basic energy analysis using utility bill data, and rough cost estimates based on dollars per square foot. The deliverable is typically a prioritized list of energy conservation measures, from no-cost operational changes to larger investments worth exploring further.
Level 1 audits typically take one to three days.
Level 2: Energy survey and analysis
A Level 2 audit typically delivers the detailed, quantified findings most useful for capital planning and regulatory compliance. It includes a comprehensive building survey, a more rigorous energy model, and itemized cost estimates with life cycle cost analysis for each recommended improvement.
Level 2 is often the most relevant tier for commercial property managers. New York City’s Local Law 87 mandates energy audits and retro-commissioning every 10 years for buildings 50,000 gross square feet or more, and many utility incentive programs may require Level 2 documentation as well. Most Level 2 audits are completed within two to four weeks.
Level 3: Detailed analysis of capital-intensive modifications
A Level 3 audit is built for major capital decisions. Auditors calibrate the energy model against actual building performance data, cost estimates approach design-level precision, and the analysis typically supports complex retrofits or projects where financing depends on reliable savings projections. Given the depth of data collection required, Level 3 audits commonly extend from one to three months.
How to prepare for a building energy audit
With the audit level selected and a timeline in view, preparation becomes the next priority. For property managers, document readiness is often the most controllable factor in how well an audit goes. Missing records can trigger additional field work or data requests, while early coordination helps keep the process on track.
Preparation timeline: Eight or more weeks out
Most building teams work toward audit day in stages. A practical sequence typically looks like this:
- Eight or more weeks out: determine the appropriate audit level, confirm any compliance deadlines, and engage a qualified auditor
- Six to eight weeks out: gather 24 months of utility bills for all fuel types, pull together building drawings and equipment schedules, and set up an Environmental Protection Agency (EPA) ENERGY STAR Portfolio Manager account
- Three to four weeks out: brief operations staff, notify tenants, request interval data (time-stamped energy readings) or sub-metering data from the utility, and compile prior audit reports and commissioning records
- Two weeks out: arrange security access, confirm escort assignments, and schedule access to any restricted areas
- Day of audit: operations staff on-site, all mechanical and electrical spaces unlocked, building automation access ready
Each milestone builds on the one before it, and falling behind early can limit the time available for later steps.
Commonly requested documents
Auditors generally ask for documentation across several categories. Organizing these materials in advance can help reduce delays and keep costs in check.
- 24 months of utility bills across all fuel types, with interval or sub-metering data if available
- Architectural and mechanical, electrical, and plumbing (MEP) drawings, preferably as-built
- Controls manuals and documentation of how building systems operate
- Maintenance logs and preventive maintenance schedules for major systems
- Major equipment inventory listing make, model, age, and capacity
- Occupancy schedules and space use inventory with floor area by function
- Prior energy audit reports, commissioning records, and any existing energy management plan
- Current ENERGY STAR account
These records may help auditors evaluate systems more thoroughly and develop better-supported recommendations. Tenant lease structure is also worth noting separately, as it can affect audit scope by shaping metering boundaries and how energy costs are allocated.
Stakeholder coordination and building access
Auditors typically interview building operations staff during the site visit, so briefing the maintenance team beforehand on what to expect can improve the quality of data collected. Advance preparation typically also includes gathering tenant notifications, building automation system access credentials, and controls vendor contact information. Those logistics also extend to physical access: auditors typically need access to mechanical rooms, electrical rooms, and roof-mounted HVAC equipment on audit day.
Pre-audit interview preparation
Auditors typically share a questionnaire ahead of the site visit and conduct a pre-audit interview to discuss the building’s specific context and goals. Common topics include primary audit goals, known problem areas, recent capital improvements, and budget parameters for recommended measures.
What the audit report covers
The preparation steps leading up to audit day, from document gathering to the pre-audit interview, are ultimately in service of one deliverable: a written report documenting findings across the building systems evaluated. The structure and depth depend on the audit level, but most Level 2 and Level 3 reports include an executive summary, an energy use breakdown by system, and a prioritized list of energy conservation measures with estimated costs and savings for each.
Auditors typically rank recommended measures by payback period, separating low-cost operational changes from larger capital investments. This approach helps building owners and property managers match improvements to available budget and planning cycles rather than treating all findings as equally urgent.
The findings may also carry value beyond on-site improvements alone. Audit reports commonly serve as documentation for regulatory compliance, support utility rebate applications, and provide baseline data useful for ongoing performance tracking.
Why preparation matters for building energy audit outcomes
A building energy audit may help property managers and building owners better understand energy consumption, system performance, and potential savings opportunities. Documentation, audit level selection, and stakeholder coordination all may influence how useful the final report turns out to be. That preparation may carry increasing weight as energy mandates expand across U.S. cities and building performance standards continue to tighten.
For property managers and building owners operating in that environment, managing audit preparation, compliance deadlines, or decarbonization planning decisions, experienced professionals may help ensure audit findings address the specific needs of each building.
Contact Us to speak with a Rimkus expert about building energy audit support for commercial properties.
Frequently asked questions
How much does a building energy audit cost for each ASHRAE level, and what factors influence the price?
Costs vary by building size, complexity, location, and audit level. Level 1 audits are less resource-intensive than Level 2 or Level 3, which involve deeper analysis, extended site visits, and calibrated energy modeling. As a general reference, Level 2 audit costs for commercial buildings often range from $0.10 to $0.35 per square foot, though actual fees depend on the building and scope.
What qualifications or certifications should a building energy auditor hold to ensure a credible and compliant audit?
Qualified auditors typically hold Certified Energy Manager (CEM), Building Energy Assessment Professional (BEAP), or Professional Engineer (PE) credentials. ASHRAE Standard 211 defines qualification through DOE Better Buildings Workforce Guidelines-approved certification, licensure, authority having jurisdiction (AHJ) approval, and verified commercial auditing experience.
What is the difference between a Level 1, Level 2, and Level 3 energy audit?
A Level 1 audit is a walk-through survey that identifies rough energy savings opportunities and low-cost measures. A Level 2 audit provides a comprehensive building survey with itemized cost estimates and life cycle cost analysis for each recommended improvement – the level most commonly required for regulatory compliance. A Level 3 audit is built for major capital decisions, with a calibrated energy model, design-level cost estimates, and analysis that can support complex retrofits or financing applications.
Authored by: Rimkus Built Environment Solutions Marketing Team
Published April 10, 2026.
This article is intended to provide general information and insights into prevailing industry practices. It is not intended to constitute, and should not be relied upon as, legal, technical, or professional advice. The content does not replace consultation with a qualified expert or professional regarding the specific facts and circumstances of any particular matter.