The energy audit playbook: How to turn building walkthroughs into long-term savings

Energy audits have a reputation for producing thick reports that collect dust. But done right, a building energy audit is one of the highest-value things an energy manager or facilities leader can do—not just once, but repeatedly over time.

This isn’t about hiring a consultant and waiting for a deliverable. It’s about building a systematic practice of observation, documentation, and follow-through that compounds over months and years.

Here’s how to do it.

What is an energy audit, really?

Most definitions will tell you an energy audit is a systematic inspection of energy use in a building designed to identify inefficiency and lower utility costs. That’s accurate, but it undersells the point.

A good energy audit is the foundation of your entire energy management program. It’s how you establish baselines, build credibility with facilities teams, find the problems hiding in plain sight, and build the business case for capital investments down the road.

The goal isn’t just to find waste. It’s to reduce waste without compromising safety, comfort, building integrity, or your organization’s mission. That distinction matters especially when you’re proposing changes that affect how people work.

ASHRAE audit levels: Matching depth to your objective

Before you walk a single hallway, know what you’re trying to accomplish. Audits come in different shapes and sizes, and the right level depends on where you are in your program.

Level 1: Walk-through survey

Quick, low-cost, focused on identifying “low-hanging fruit.” You’re looking for obvious operational problems, no-cost or low-cost fixes, and a preliminary read on where energy waste is happening. The goal is immediate savings.

Level 2: Energy survey and analysis

This is the commercial-grade audit. You’re doing detailed energy breakdowns, utility bill analysis, benchmarking, and financial analysis of recommended energy conservation measures (ECMs). This is where most organizations should spend the majority of their audit effort.

Level 3: Detailed analysis/investment grade

Reserved for major capital projects. Uses whole-building computer simulation, calibrated energy models, and in-depth data collection. The goal is long-term savings with defensible financial projections—typically required for performance contracts or large bond-funded projects.

The three phases of a real-world audit program

An audit isn’t a one-time event. Think of it as a program with three distinct phases that evolve as your knowledge of the buildings deepens.

Phase 1: The Honeymoon

When you’re new to a building or new to an energy management role this phase is about observation, relationship-building, and finding your early wins.

What to do:

• Introduce yourself to the security team, facilities staff, and building leadership. You need their trust and their keys.
• Get access to mechanical rooms, the basement, the roof, outbuildings, and meters. Every one of them.
• Walk the building at different times: occupied and unoccupied, day and night, mornings and evenings, holidays. Energy waste doesn’t keep business hours.
• Confirm occupancy patterns. Are HVAC systems running on weekends when the building is empty? Are schedules set correctly in the BAS?
• Check thermostats and document what you see—are they manual, programmable, or BAS-controlled? Are there override signs on the wall? What are the setpoints?
• Look for heating and cooling running simultaneously. Simultaneous heating and cooling (also called HVAC fighting) is one of the most common and costly operational problems in commercial buildings.
• Understand the preventative maintenance program and work order system. This tells you a lot about how well the building is managed.
• Ask about past humidity or moisture events. These indicate envelope or HVAC problems that affect both energy and indoor air quality.
• Locate all your meters—electric, gas, water, steam—and map them to the buildings they serve.

The early win matters. Find something significant quickly like a billing error, a building running 24/7 that shouldn’t be, or a comfort complaint you can actually fix. Credibility with the facilities team is earned, not assumed, and nothing builds it faster than solving a real problem.

Phase 2: Making operational changes

Once you know the buildings and have the relationships, it’s time to dig into data and start making changes—without spending capital.

What to do:

• Get view-only access to the Building Automation System (BAS). You’re not there to make changes—you’re there to observe anomalies. Look for equipment running outside schedules, setpoints that don’t match policy, sensors that are out of range.
• Benchmark your buildings using Energy Use Intensity (EUI). This normalizes consumption by square footage and lets you compare buildings of different types on a level playing field. It’s how you find your energy hogs (and your stars.)
• Investigate unusual patterns in utility data—unexpected demand spikes, consumption that doesn’t track with weather or occupancy, bills that don’t make sense.
• Document chiller and boiler settings across buildings. Inconsistency is a red flag. If three identical boilers in similar buildings are running at three different settings, something is wrong.
• Establish regular meetings with facilities leadership to share findings. Dashboards and simple charts go a long way. Show them what’s happening in their buildings in terms they understand.
• Propose HVAC operational changes thoughtfully. Always confirm that comfort won’t be compromised before you make a recommendation. Your credibility depends on it.

A simple operating philosophy worth keeping in mind: If you can’t turn it off, set it back. If you can’t set it back, tune it up.

Phase 3: Preparing for efficiency improvements

Now you’re ready to talk capital. You have the data, the relationships, and the operational wins to back up your recommendations.

What to do:

• Document nameplate information on major equipment, like motors, chillers, boilers, RTUs. Serial numbers, model numbers, rated efficiency, voltage, and amperage. This is your asset inventory and it’s essential for lifecycle planning.
• Evaluate lighting first. LED retrofits typically offer the fastest payback of any efficiency measure and are the easiest projects to get approved. Use them to build momentum.
• Blend quick-payback and long-term ROI projects in your recommendations. Finance and leadership want to see a mix, not all 10-year paybacks.
• Map equipment age and lifecycle. Know which assets are approaching end-of-life so you can time efficiency upgrades with planned replacements instead of emergency replacements.
• Consider a performance contract if capital is constrained. Energy Services Companies (ESCOs) can fund improvements through guaranteed savings—a viable path for organizations that can’t access traditional capital.
• Think about electrification. As equipment ages out, the replacement decision is increasingly a conversation about electrification—heat pumps, EV charging infrastructure, and on-site generation.

What to look for in the field

Experienced energy managers develop an eye for waste. Here’s a short list of what to watch for on every walkthrough:

• Switches in “Hand” mode. Equipment locked in manual override means it’s running on someone’s judgment, not a schedule or sensor. It’s almost always running more than it needs to.
• Air compressors that never cycle off. A compressor that runs continuously or short-cycles is a sign of a compressed air leak. These are common, costly, and easy to miss.
• Dirty or improperly seated air filters. A filter installed at an angle or loaded with dust is choking your air handler and driving up energy consumption.
• Covered or blocked ventilation. Blocked intakes and exhausts cause pressure problems, comfort complaints, and IAQ issues.
• Broken RTU doors. An open rooftop unit door exposes the internals to weather and drives up energy consumption.
• Ceiling stains. Water stains on ceiling tiles are evidence of past moisture events. Follow the trail to find HVAC or envelope problems.
• Redundant systems both running. Backup pumps and fans left in operation alongside primary equipment double your energy use for no operational benefit.

The role of data: Before, during, and after the audit

The field work is only half the picture. The other half is what happens when you connect what you see in the building to what the data shows.

• Before the audit: Pull 24 months of utility bill history. Look for anomalies before you walk the building—they’ll tell you where to focus.
• During the audit: Use interval data and trend data from the BAS or smart metering to validate what you’re observing. A spike at 3 AM in an “unoccupied” building is a real problem.
• After the audit: Connect your findings to the data. Use EUI benchmarking to rank buildings. Use cost avoidance calculations to quantify what operational changes have already saved. Use trend data to build the business case for capital projects.

This is where a centralized utility data platform pays for itself. When your bill data, interval data, benchmarking, and reporting all live in one place, audit findings become business cases, not just observations.

The bottom line

A building energy audit is not a report. It’s a practice. The energy managers who consistently deliver results are the ones who walk their buildings regularly, build trust with their facilities teams, connect field observations to utility data, and keep showing up, phase after phase.

The tools have gotten better. The data is more available than ever. But the fundamentals haven’t changed: show up, look carefully, ask good questions, and follow through.