What to Expect During an Energy Audit: A Practical Guide for Building Owners and Managers
If you’ve been thinking about getting an energy audit but aren’t sure what it actually involves, this guide is for you. We’ll walk you through the process step by step — no engineering background required.
Energy costs are one of the largest operating expenses for any commercial or institutional building — and for most owners and managers, there’s a nagging sense that things could be running more efficiently. But knowing where to start can be a challenge.
That’s exactly where an energy audit comes in. Think of it as a health check for your building: a professional, independent review of how your building uses energy, where it’s being wasted, and what you can do about it. Done well, an energy audit doesn’t just tell you what’s wrong — it gives you a clear, costed roadmap to fix it.
In this article, we’ll explain what a building energy audit involves, what you can expect from the process, and how Efficiency Engineering approaches audits to make sure you get results you can actually act on.
Why Get a Building Energy Audit?
Buildings account for a significant share of Canada’s energy use and greenhouse gas emissions — and the majority of the buildings in use today were built before modern energy standards existed. That means there’s often substantial room for improvement, even in buildings that appear to be running well.
A professional energy audit gives you:
A clear picture of where your energy dollars are going
Specific, prioritized recommendations for improvement — with cost and savings estimates attached
The documentation you need to access government grants, utility rebates, and retrofit financing
A baseline for tracking and reporting energy performance over time
Whether you manage a single office building, a multi-residential complex, or a portfolio of properties, an energy audit is typically the smartest first step toward meaningful, lasting energy savings.
“Buildings that have been professionally audited typically uncover energy savings opportunities in the range of 15–30%. The audit doesn’t commit you to spending — it tells you where spending will have the greatest impact.”
Understanding the Three Levels of Energy Audit
Not all energy audits are created equal. The most widely used framework comes from ASHRAE (the American Society of Heating, Refrigerating and Air-Conditioning Engineers), which defines three levels of increasing depth and detail. Understanding the differences helps you choose the right scope for your situation.
Level 1 — Walk-Through Assessment
A high-level review of your building and utility bills. It’s useful for getting a quick sense of where the big opportunities might be, but it stops short of the detailed analysis needed to make capital investment decisions.
This level is often a starting point for larger portfolios or preliminary feasibility work. It is useful as a screening tool to allow building owners & managers to quickly and inexpensively compare the performance of multiple facilities and highlight where the largest opportunities for improvement lie.
Level 2 — Energy Survey and Analysis
This is the most commonly commissioned audit — and the level most building owners need. A Level 2 audit involves a thorough site survey, a review of your building’s systems and equipment, energy modelling, and a prioritized list of improvement opportunities. Each recommendation comes with estimated costs, projected savings, and payback periods, giving you everything you need to make informed capital planning decisions.
Level 3 — Detailed Engineering Analysis
Reserved for complex projects or major system replacements where a higher level of financial certainty is required before committing significant capital. Level 3 audits involve detailed engineering calculations and investment-grade cost analysis.
For most commercial and institutional building owners, a Level 2 audit is the right starting point. It’s thorough enough to support real decision-making, without the cost and time commitment of a Level 3 study.
What Happens During a Level 2 Energy Audit?
A Level 2 energy audit typically unfolds in three phases. Here’s what to expect at each stage.
Phase 1: Data Gathering
Before the site visit, your auditor will ask for some background information: typically 24–36 months of utility bills, building drawings, equipment records, and any recent maintenance history. The more complete this information, the sharper the audit findings will be — but don’t worry if your records aren’t perfect. A good auditing team will work with what’s available.
Phase 2: Site Visit
The site visit is where the hands-on work happens. Your engineering team will walk the building, inspect your mechanical and electrical systems, review your HVAC equipment, lighting, building envelope, and controls, and observe how the building operates day-to-day.
One of the most valuable parts of the site visit is the conversation with your facilities manager or building operator. The people who work in and around the building every day often have the most practical insights — the equipment that runs hot, the zone that’s always too cold, the controls that were never quite set up right. Good auditors listen carefully to these observations.
For a typical mid-size commercial building, the site visit takes half a day to a full day. You don’t need to be present the entire time, but it’s worth being available at the start and end for a brief introduction and debrief.
Phase 3: Analysis and Report
After the site visit, your engineering team models the building’s energy use, benchmarks it against comparable buildings, and develops a set of recommendations tailored to your specific building and goals. Each recommendation is assessed for implementation cost, projected annual energy savings, payback period, and — increasingly important for many owners — greenhouse gas reductions.
Depending on the size and complexity of your building, this phase typically takes two to four weeks.
How Efficiency Engineering Goes Further
While all Level 2 audits follow the same general ASHRAE framework, the quality of the analysis — and the usefulness of the final report — can vary significantly depending on the engineering team and their methodology. At Efficiency Engineering, we deliberately go beyond the standard Level 2 requirements in ways that make a real difference for our clients.
More Accurate Energy and Cost Projections
Standard Level 2 audits can rely on generalized assumptions to estimate energy savings. We take a more rigorous approach: detailed system modelling, site-specific operating data, and careful validation against your actual utility consumption. The result is projections you can trust — with less uncertainty when it comes to budgeting and capital planning.
Existing-Condition and Retrofit Schematics
Our audit reports include both existing-condition schematics and proposed retrofit drawings — clear visual representations of how your systems are currently configured and how they would look after the recommended improvements. This level of documentation is not required under standard Level 2 guidelines, but it makes a significant difference when it comes to getting retrofit work tendered, approved, and implemented efficiently.
Room-by-Room Lighting Inventories
Where lighting upgrades are a consideration — which they often are — we conduct a comprehensive room-by-room lighting inventory, capturing precise fixture counts and types throughout your building. This level of detail allows us to provide highly accurate lighting upgrade recommendations and cost estimates, rather than the rough approximations that can result from less thorough approaches.
Full 20-Year Lifecycle Cost Analysis
For every recommended measure and implementation pathway, we perform a full 20-year lifecycle cost analysis. This means you’re not just looking at simple payback — you’re seeing the complete financial picture over time: avoided capital costs, long-term utility savings, maintenance cost trends, and the effects of inflation and energy price escalation. This level of analysis allows you to make genuinely informed decisions about which improvements to prioritize and when, with a clear understanding of both short-term and long-term financial outcomes.
Together, these enhancements give our clients a deeper, more reliable foundation for decision-making — and a smoother path from audit findings to actual implementation.
What You’ll Receive at the End
A well-prepared Level 2 audit report is a decision-making document, not a shelf piece. At the end of the process, you should have:
A breakdown of your building’s current energy use by system (HVAC, lighting, plug loads, domestic hot water, etc.)
A benchmarking comparison against similar buildings
A prioritized list of Energy Conservation Measures (ECMs) with implementation costs, projected savings, and payback periods
Existing-condition and proposed retrofit schematics for recommended system changes
A 20-year lifecycle cost analysis for each measure and implementation pathway
A summary of applicable grants, rebates, and incentive programs available to you
A greenhouse gas emissions baseline and projected reductions for each measure
The report is designed to give you everything you need to make confident, well-informed decisions about your building — whether you’re planning a phased improvement program, preparing a capital budget, applying for funding, or simply trying to understand where your energy dollars are going.
Common Questions
How long does the process take?
From initial engagement to final report, a Level 2 audit on a typical mid-size commercial building generally takes four to six weeks. Larger or more complex buildings may take longer.
How much does an energy audit cost?
Audit fees vary depending on building size and complexity. It’s also worth knowing that many Ontario building owners may be eligible for funding support through programs and various utility-sponsored initiatives. We’ll help you identify what’s available to you as part of the engagement.
Do we have to implement the recommendations?
Absolutely not. The audit is an independent assessment and the decision of what to implement, and when, is entirely yours. That said, having a professionally prepared audit report significantly strengthens your position when applying for retrofit financing, incentive programs, or sustainability certifications.
What’s the difference between an energy audit and retro-commissioning?
Retro-commissioning focuses on getting your existing systems to perform the way they were originally designed to. An energy audit identifies both operational improvements and capital upgrade opportunities. The two are complementary, and in some cases, we recommend doing both.
Ready to Get Started?
An energy audit is one of the most valuable investments a building owner or manager can make. It replaces guesswork with evidence, turns general intentions into specific plans, and gives you the foundation you need to reduce costs, improve comfort, and meet your sustainability goals.
At Efficiency Engineering, we’ve helped building owners understand their buildings and take meaningful action on energy performance. If you’re thinking about an energy audit — or just want to understand whether it’s the right step for you — we’d welcome the conversation.
Get in touch with our team to discuss the right audit scope for your building, find out what funding may be available, and take the first step toward a more energy-efficient operation.