When Ontario building owners compare Energy Audit vs Building Commissioning services, the right first step depends on the decision they need to make. A commercial building energy audit examines how a property uses energy and identifies measures that could reduce consumption, utility costs, or greenhouse gas emissions. Building commissioning tests whether installed systems are operating according to the owner’s requirements, design documents, control sequences, and current operating needs.
An energy audit is usually the better starting point when utility costs are high, no recent energy assessment is available, and the owner needs a prioritized improvement plan. Building commissioning deserves priority after new construction, a major HVAC retrofit, a significant occupancy change, or when modern equipment continues to produce comfort and performance problems.
Cost and timing depend on scope. A Level 1 energy audit may require less time than comprehensive commissioning, while a Level 3 audit can involve extensive measurement and modelling. Proposals should therefore be compared by the systems, testing, analysis, and deliverables included, rather than by the service name alone.
Energy audit vs building commissioning at a glance
| Point | Energy audit | Building commissioning |
|---|---|---|
| Primary question | Where is energy being used, and which improvements make financial and technical sense? | Are building systems installed, controlled, and operating as intended? |
| Main evidence reviewed | Utility data, operating schedules, equipment information, benchmarks, site observations, and measurements | Owner’s requirements, design documents, sequences of operation, BAS trends, test results, and operator input |
| Typical trigger | Unexplained energy use, rising utility costs, retrofit planning, benchmarking, or capital budgeting | New construction, a major renovation, persistent comfort complaints, control problems, or performance drift |
| Fieldwork | Building walk-through, equipment review, staff interviews, and selected measurements | System verification, control review, functional performance testing, and deficiency tracking |
| Main deliverable | Energy conservation measures with estimated savings, costs, and financial metrics | Test records, a deficiency log, corrective actions, and a commissioning report |
| Role in capital planning | Evaluates operational measures and capital upgrades | Focuses mainly on system performance but may identify repair or replacement needs |
| HVAC focus | Efficiency, energy use, condition, and retrofit opportunities | Sequences, schedules, sensors, setpoints, interlocks, airflow, and actual system response |
| Common next step | Feasibility study, design, incentive application, or retrofit implementation | Corrective work, retesting, operator training, or ongoing commissioning |
| Ontario incentive relevance | May support planning and documentation for eligible retrofit projects | Qualifying properties may be eligible for Ontario’s Existing Building Commissioning program |
What a commercial building energy audit evaluates
A commercial building energy audit starts with the property’s energy data. Depending on the scope, the auditor may review electricity and fuel consumption, peak demand, seasonal patterns, operating hours, Energy Use Intensity, and changes in occupancy or production.
The site review connects those records to the way the building operates. The auditor examines major energy-using systems such as HVAC equipment, lighting, domestic hot water, controls, motors, pumps, fans, and the building envelope. Interviews with facility staff help explain operating schedules, recurring maintenance problems, tenant requirements, and temporary overrides that may not appear in utility data.
The resulting energy conservation measures may include operational changes, maintenance work, or capital improvements. Examples include:
- Adjusting equipment schedules or temperature setpoints
- Installing lighting controls
- Improving insulation or air sealing
- Adding variable-speed drives
- Upgrading boilers, chillers, rooftop units, or heat pumps
- Revising building automation strategies
- Improving metering and energy monitoring
A detailed audit normally estimates the energy and cost savings, implementation cost, and financial performance of each recommended measure. These figures support planning, but they remain estimates until a project is designed, installed, and measured under actual operating conditions.
An energy audit in Ontario is particularly useful when the owner needs to compare several potential projects, establish a capital plan, or prepare technical information for an incentive or financing application.
What building commissioning checks
Building commissioning is a quality-assurance process. It verifies how systems perform under real operating conditions and documents deficiencies that prevent the building from meeting its requirements.
A commissioning provider may review drawings, equipment schedules, sequences of operation, previous test reports, building automation system trends, and operation and maintenance records. Functional performance testing then checks how equipment responds in different modes.
For example, the provider may command an air-handling unit through occupied and unoccupied operation, test a temperature sensor, verify an alarm, or confirm that heating and cooling equipment respond in the correct sequence. This work can reveal issues that utility bills cannot identify on their own, including:
- Outdated operating schedules
- Incorrect setpoints
- Sensors that are out of calibration
- Disabled alarms or control sequences
- Simultaneous heating and cooling
- Economizers that do not operate correctly
- Air or water balance problems
- Valves or dampers that fail to close
- Equipment that cannot meet current occupancy needs
Commissioning can reduce energy waste, although it may also be initiated to improve comfort, reliability, indoor air quality, documentation, or operator readiness. The exact objective should be defined before testing begins.
ASHRAE energy audit levels and their deliverables
ASHRAE Standard 211 establishes consistent practices for commercial building energy audits and defines three levels of effort. The standard is voluntary unless a contract, incentive program, or jurisdiction specifically requires it.
ASHRAE Level 1 energy audit
A Level 1 audit is a walk-through assessment. It generally includes a preliminary review of utility data, interviews with facility staff, and a site visit focused on major systems.
The report identifies visible energy-saving opportunities and highlights areas that may justify further analysis. It is suitable for early screening, portfolio planning, or a property that has never completed a formal energy review.
ASHRAE Level 2 energy audit
A Level 2 audit provides a more detailed energy survey and analysis. It examines major end uses, operating conditions, system performance, and practical energy conservation measures.
The report typically includes estimated energy savings, implementation costs, and financial metrics for each recommended measure. This level is often appropriate when an owner needs enough information to compare projects and establish a retrofit budget.
ASHRAE Level 3 energy audit
A Level 3 audit provides detailed analysis of selected capital-intensive measures. It is often called an investment-grade audit and is usually used when a major project requires stronger technical and financial validation.
The work may include temporary metering, equipment-level analysis, calibrated energy modelling, detailed cost estimates, and an assessment of project risks. Calibrated whole-building modelling can be part of a Level 3 scope, but it is not automatically required for every project. The methodology should match the measure being evaluated.
The level should be written into the proposal along with the systems included, required measurements, modelling approach, financial assumptions, and final deliverables. ASHRAE also publishes an overview of its commercial building energy audit procedures.
Commissioning, recommissioning, and retro-commissioning
New building commissioning begins during design and continues through construction, testing, handover, and early operation. Starting during design allows the commissioning provider to review the owner’s project requirements, basis of design, control sequences, and planned tests before systems are installed.
Existing building commissioning, often shortened to EBCx, is an umbrella term for commissioning work performed in an occupied or operating property.
Recommissioning applies to a building that was commissioned previously but needs its systems tested and optimized again. Changes in occupancy, equipment, controls, or maintenance practices can cause performance to drift over time. Retro-commissioning generally applies to an existing building that did not receive formal commissioning when it was constructed. It establishes current requirements, tests system performance, and identifies operational or maintenance corrections. The U.S. Department of Energy’s commissioning guide provides a useful summary of these distinctions.
When an energy audit should come first
Schedule an energy audit first when:
- Utility costs are high, but the cause is unclear
- The building has no recent energy baseline or formal assessment
- The owner needs to compare several retrofit opportunities
- A capital plan requires estimated costs, savings, and payback
- Management wants to benchmark one building against similar properties
- The project team needs technical information before applying for an eligible retrofit incentive
A Level 1 audit may be enough for preliminary screening. A Level 2 audit is more suitable when the owner expects to select and budget specific measures.
When building commissioning should come first
Building commissioning should take priority when the building has recently completed construction, undergone a major renovation, or received new HVAC equipment that has never been tested under normal operating conditions. At this stage, the owner needs evidence that the installed systems respond correctly, maintain comfort, and follow the approved sequences of operation.
It is also the better starting point when complaints continue even though the equipment is relatively new. Uneven temperatures, poor ventilation, excessive equipment runtime, repeated overrides, and unexplained changes in energy use often indicate an operating or controls problem. A commissioning provider can test the affected systems, review automation trends, check sensor calibration, and compare actual performance with the design requirements.
Completing this work before an energy audit can improve the quality of the audit baseline. If an air-handling unit follows the wrong schedule or heating and cooling operate at the same time, current utility data reflects a fault rather than normal building performance. Correcting those issues first gives the auditor a clearer picture of the building’s remaining energy-saving opportunities. In some cases, commissioning resolves the main problem without an equipment replacement. In others, its findings show exactly where a later energy audit or capital study should concentrate.
- New construction or a major renovation is approaching handover
- Recently installed HVAC equipment has not been performance-tested
- Temperature or ventilation complaints continue despite modern equipment
- Controls show overrides, incorrect schedules, or excessive equipment runtime
- Heating and cooling systems operate at the same time
- Energy use changed after an occupancy or control-system update
When both services make sense؟
A large or technically complex building may need both services. The scopes can share utility data, equipment records, operating schedules, and staff interviews, but the analysis and deliverables remain different.
The sequence depends on the building:
- An energy audit may identify a control or operational problem that requires targeted retro-commissioning.
- Commissioning may stabilize building operation before an audit evaluates major capital improvements.
- A coordinated scope may assess energy opportunities and system performance together when both questions are urgent.
Combining the work does not always mean every activity can occur during one site visit. Functional testing may require access at specific times, seasonal conditions, trend data, corrective work, and retesting. The proposal should state which activities will be coordinated and which require separate visits.
Ontario incentives for audits, retrofits, and commissioning
Ontario programs treat retrofit projects and existing building commissioning as separate activities.
The Save on Energy Existing Building Commissioning program supports qualifying commercial and institutional buildings that improve performance through operational, maintenance, and behavioural measures. As of August 2026, key facility requirements include at least 12 months of consecutive energy data, annual electricity consumption of at least 750,000 kWh excluding process loads, and no recommissioning exercise within the previous two years.
The program includes investigation, implementation, and persistence phases. It requires an approved commissioning provider and program-specific reporting. Building owners should confirm current eligibility and obtain the required approvals before beginning work.
The separate Save on Energy Retrofit Program supports eligible equipment upgrades. An energy audit can help identify and evaluate those upgrades, but completing an audit does not automatically make a project eligible for funding.
Program rules, incentive rates, and application deadlines can change. Current requirements should be checked before equipment is ordered, installed, or included in a construction contract.
What should your building book first?
Choose an energy audit when the immediate decision is where to invest. Choose building commissioning when the immediate concern is whether installed systems are performing properly.
If both questions remain open, begin with a scoping review of utility data, available design documents, recent projects, and reported operating problems. That review can determine whether the services should be completed sequentially or under one coordinated scope.
Green Canada Energy Advisors provides ASHRAE-based energy audits and building commissioning services for commercial, institutional, and multi-unit residential buildings. Our team can review your building’s available records and define a scope based on the decisions the assessment needs to support.
