If you’ve ever handed over a project and immediately started getting calls about system issues, you already know why commissioning matters.

The commissioning process isn’t an extra add-on. It’s how you make sure the building systems actually do what they’re supposed to. It’s about verifying performance, catching mistakes before they become rework, and saving everyone time, money, and headaches down the line.

In this guide, we’re walking through what commissioning looks like from start to finish. No extra fluff. Just the real steps, real challenges, and what teams need to get it done right—whether you’re on a fresh build or fixing gaps in an older facility.

What Is Building Commissioning?

Building commissioning is the structured process of verifying and documenting that the systems and equipment installed in a facility—think heating ventilation and air, lighting controls, fire alarms, and more—are designed, installed, tested, and operated in accordance with the owner’s project requirements.

That includes:

✔ Confirming that the design intent is met

✔ Making sure project components are fully functional under real-life conditions

✔ Delivering complete training and manuals to the operations team

✔ Identifying and correcting any issues before or shortly after occupancy

There are different types of commissioning depending on when and how it’s applied:

• New construction commissioning – Integrated from the design and construction phases onward
• Retro-commissioning – Applied to existing buildings that were never commissioned originally
• Continuous commissioning – Ongoing evaluation and fine-tuning of systems over time
• Re-commissioning – Revisiting a facility’s performance after years of operation to correct drift

In any form, it’s a quality and performance check on the building’s operations and energy efficiency with real financial implications for the building owner.

Need a broader definition before the deep dive? Read our primer on what building commissioning really is and why it pays off.

Why Is Building Commissioning Important in A&E?

A&E firms are on the hook for more than just pretty drawings and design calculations. Your reputation is tied to how the building actually performs—whether that’s HVAC systems running reliably or lighting controls responding to occupancy sensors the way we promised.

Here’s why building commissioning matters:

• Performance verification: Proves that what was designed is actually what’s operating.
• Energy and environmental design goals: Helps meet LEED, WELL, and other certification standards.
• Fewer surprises for the owner: You don’t want the building owner calling you six months later because the air conditioning in their data center can’t keep up.
• Lower operational costs: Well-commissioned building systems mean fewer maintenance calls, better energy use, and less wear on equipment.
• Better project delivery: A defined commissioning plan keeps everyone—design team, construction team, trade contractors, and operations team—aligned with fewer RFIs and do-overs.

In short, commissioning helps you back up your design work with performance data. That’s the kind of accountability that clients remember.

The Commissioning Process: Step-by-Step

Commissioning shouldn’t be tacked on at the end of a project. To get it right, it needs to be planned from day one, integrated into the project timeline, and backed by collaboration across teams. When that happens, commissioning does what it’s meant to do: confirm that the systems perform as promised and deliver long-term value to the client.

Here’s how the process unfolds, from initial planning through post-occupancy.

Step 1: Project Planning & Owner’s Project Requirements (OPR)

Every successful project starts with clarity—and that begins with defining the owner’s project requirements. The commissioning provider (CxP) works with the owner and design team to document exactly how the building should perform. This includes things like temperature setpoints, energy targets, maintenance expectations, and any special needs for the building type (like 24/7 cooling for server rooms or air cleanliness in labs).

Based on the OPR, the CxP then develops a commissioning plan. This is a detailed document that outlines:

• The systems to be commissioned (HVAC, lighting, fire alarms, etc.)
• The objectives of commissioning (e.g., energy performance, safety, comfort)
• The tests that will be performed
• The schedule and milestones for commissioning activities

This plan keeps everyone aligned from day one and becomes the backbone of the entire process.

Step 2: Design Phase Commissioning

Once the design team gets to work, the CxP begins reviewing the plans, building specifications, and control strategies to ensure they align with the OPR and can actually be tested later.

If something’s missing—say, there’s no way to test a boiler’s staging logic, or a valve isn’t accessible—the CxP flags it and suggests changes. This review also helps catch conflicts between disciplines that often slip through in design.

Throughout the design and construction phases, the CxP meets regularly with the design team to stay in sync. These reviews aren’t just a formality—they’re a chance to make sure the systems can be commissioned properly once installed.

Step 3: Construction Phase Commissioning

This is where systems go from drawings to real equipment on-site. The CxP stays closely involved during construction to make sure everything is installed correctly, accessible, and matches the approved design.

They walk the site regularly, observe key installations, and review contractor submittals. If a damper is installed in the wrong location or a sensor is placed too high on the wall, the CxP catches it early—before ceilings are closed or equipment is powered up.

This is also when startup testing begins. Unlike full performance testing, startup checks are basic: verifying that systems turn on, run safely, and respond to manual controls. Think of it as flipping the switch and making sure the lights come on and the air handler doesn’t throw an alarm.

The CxP also begins drafting functional test procedures, which will be used in the next phase.

Step 4: Functional Performance Testing

Now it’s time to verify that everything works as intended. Functional performance testing is where systems are tested under real or simulated operating conditions, based on the OPR. Digital checklists and trend logs captured in dedicated building commissioning software keep those scripts tight and the data audit-ready—long before you hand anything over to the owner.

For HVAC, this might involve raising the room temperature and verifying that the cooling kicks on, dampers modulate, and setpoints are maintained. For lighting, it might mean testing motion sensors or daylight dimming controls.

Each test follows a script, and every result is documented. If something doesn’t work—say a VAV box doesn’t respond to a control signal—the contractor is notified, the issue is fixed, and the system is retested.

The CxP prepares commissioning reports during this phase. These reports include:

• Test results and outcomes
• A list of issues or deficiencies
• Recommendations for fixes or improvements
• Confirmation of final system status

These reports are reviewed by the owner, design team, and construction team to make sure all concerns are addressed before the project is wrapped up.

Step 5: Systems Manual & Training

Testing is done—but you’re not finished. Now it’s time to hand off the building to the people who will actually run it.

The CxP assembles a systems manual that includes:

• As-built drawings
• O&M documentation
• Testing results
• Alarm response guides
• Vendor and warranty contacts

Equally important is the training for the operations team. This is where the facilities staff learns how to manage and maintain the systems they’ve inherited. The training should be hands-on and practical—not a vague PowerPoint session.

This phase is often rushed, but skipping it leads to a building full of equipment that no one knows how to use. That’s when good systems go bad.

Step 6: Post-Occupancy Review & Ongoing Commissioning

Even with a great handoff, real-world use can reveal new issues. That’s why good commissioning includes a post-occupancy review, usually within 8–12 months after move-in.

The CxP returns to evaluate how the systems are performing. They check BAS trend data, talk with the facilities staff, and investigate any complaints or overrides. If systems aren’t running efficiently—or if they’ve been manually adjusted to “make things work”—this is when it comes to light.

This is also the time to talk about ongoing commissioning. Some buildings, especially large or complex ones, benefit from regular inspections, trending, and seasonal performance checks. That might mean quarterly tune-ups, annual testing, or automated diagnostics built into the BAS.

Each of these steps builds on the last. If you skip one—or rush through it—you’ll feel it later, whether it’s in missed performance targets, frustrated owners, or costly rework.

6 Common Challenges in the Commissioning Process

Even with a solid commissioning plan, the process can go sideways. In our experience, most of the breakdowns fall into a few familiar categories. Here’s what to watch for—and how to stay ahead of it.

1. Commissioning Starts Too Late

When the commissioning provider is brought in during the punch list phase, most of the systems are already installed, tested (incorrectly), or even concealed. There’s little room to correct core issues like inaccessible valves, misconfigured sensors, or nonfunctional sequences.

To prevent this, commissioning should start during the planning stage—well before a contractor is selected. Early involvement helps shape the design and construction process and keeps everyone aligned with the owner’s project requirements.

2. The Scope Is Vague or Missing

Unclear scope creates confusion about what systems are being commissioned and to what extent. If the team assumes HVAC is in, but the lighting controls and emergency lighting were never added to the scope, you’ll run into disagreements during functional testing.

A well-defined commissioning scope should be tied directly to the OPR and confirmed in writing with the project team. This prevents last-minute surprises and missed components.

3. Teams Aren’t Communicating

Commissioning depends on collaboration. If the design team, construction team, and commissioning team aren’t in sync, systems will fall through the cracks. Common issues include incomplete submittals, outdated sequences, or equipment installed that doesn’t match the design.

The solution is structured coordination. Weekly commissioning meetings, open access to updated drawings, and shared use of project platforms like Deltek Vantagepoint keep information flowing. Everyone stays informed, and commissioning activities don’t stall.

4. Testing Is Rushed or Out of Sequence

When commissioning is squeezed into the final week before occupancy, test windows get missed and diagnostics become guesswork. Systems need time to cycle, reset, and demonstrate actual operation.

To avoid this, performance tests and system testing should be scheduled well in advance—baked into the main project schedule. The commissioning team needs proper time to verify each system under the right conditions, not while painters are still on lifts.

5. Contractors Push Back

Let’s be honest—some trade contractors see commissioning as a threat. They’re on tight budgets and tighter schedules, and an outsider verifying their installation process can feel adversarial.

But good commissioning isn’t about blame—it’s about performance. Setting expectations upfront, explaining the process, and building rapport on-site helps foster cooperation. When the CxP is part of the team, not an enforcer, the process runs smoother for everyone.

6. Documentation Is Incomplete or Inaccurate

Commissioning is only as strong as its paper trail. Missing OPRs, vague test plans, or inconsistent commissioning reports undermine the credibility of the process and create handoff issues for the operations team.

Assign responsibility for documentation early. Use standardized forms, track updates clearly, and review regularly with the full team. With proper oversight, the documentation becomes a valuable asset instead of an afterthought.

Final Thoughts on the Commissioning Process

Commissioning keeps your project from falling apart after handoff. It’s how you catch system issues before they become change orders, warranty calls, or angry emails from the owner.

The truth? Commissioning only works when everyone’s on the same page. That’s where Deltek Vantagepoint helps. It keeps the design team, construction team, and commissioning provider aligned, with one place to track issues, submittals, and test results—so nothing slips through the cracks.

If you want fewer surprises at turnover and a building that performs like it should, commission early, stay organized, and use the right tools like Deltek Vantagepoint to back it up.

Key Takeaways

• The commissioning process verifies that systems and equipment are working as intended.
• Start early, stay consistent, and document everything.
• Use tools like Deltek Vantagepoint to keep your project team, commissioning team, and construction team in sync.
• Training and follow-up matter just as much as testing.
• Whether you’re working on a construction project or retro commissioning an older facility, your attention to detail defines success.

Frequently Asked Questions