The Commissioning Gap: When New Building Systems Work on Paper but Fail in Practice

The commissioning gap

A new building can pass inspections and still disappoint the people who occupy and operate it. The commissioning gap is the distance between a system that works under scripted, ideal test conditions and a building that performs reliably under real-world conditions: full occupancy, changing heat loads, active networks and connected systems operating together.

Commissioning verifies that building systems—including HVAC, electrical, network and security—are designed, installed and functioning according to the owner's requirements. The episode emphasizes that this cannot be reduced to checking whether each component works on its own. Owners need to know whether the systems work together, whether they respond to real operating conditions and whether the people responsible for the building know how to use them.

Why passing tests may not be enough

• Idealized testing: Projects may test HVAC with only a few people present or test a network with a small number of devices. Those conditions do not represent full occupancy or the hundreds of devices that may arrive on move-in day.
• Systems tested in isolation: Contractors, low-voltage vendors, IT teams and security integrators can work in separate lanes, even though their systems depend on one another.
• Hidden dependencies: Access control traffic may depend on network provisioning, while a building automation system may rely on correct IP addresses. Integration problems can remain invisible until occupancy.
• Schedule pressure: When project schedules slip, testing is an easy step to shorten or skip, even though it is essential to verifying performance.

Testing and coordination solve different problems. Testing checks each system; coordination checks the connections between systems. A strong closeout process needs both.

When integration failures become operational emergencies

One example discussed involved a building automation system whose points, alarms and schedules had been verified. Its integration with the fire alarm had not. Three months into operation, a minor air-handling-unit fault triggered a fire alarm sequence that shut down the air-handling units. The building began pressurizing incorrectly, doors became difficult to open and the team faced an emergency response to what should have been a simple service request.

The issue was not that either system necessarily failed in isolation. The failure was in the interaction between them, which had not been tested as a whole. The episode also raises the related risk of access control and fire alarm systems giving conflicting instructions—for example, one system calling for lockdown while another calls for doors to open.

Training is part of commissioning

A final walkthrough is not a substitute for usable operator training. In one example, a newly commissioned chiller plant received a standard vendor walkthrough, but operators were not shown how to adjust set points during a heat wave. When temperatures reached 95 degrees in June, the chiller ran at 50% capacity because staff did not know how to override its schedule. Tenants reported warm offices, and the team could not resolve the problem for two days while waiting for the vendor.

Test results cannot make a building operationally ready if the people running it do not know how to respond. Operators should take part in testing from the beginning rather than receive a brief presentation at the end. Training should prepare them to use the system in relevant operating conditions, not merely show that a vendor has demonstrated it.

Documentation and first-year risks

As-built drawings can already be out of date at handover. The episode recommends maintaining living documentation that records changes, overrides and updates, so operators can understand the system over time. Without that record, troubleshooting becomes guesswork in the second, third or fifth year of operation.

Two first-year risks highlighted are undocumented overrides and unvalidated alarm points. A temporary change made by a technician or operator may remain in place for months and later create a different problem that is difficult to trace. An alarm may appear to monitor critical equipment without anyone verifying that it actually activates when needed. These issues can turn routine maintenance into a surprise and disrupt tenants.

The impact is not limited to repair costs. When a tenant's business is disrupted, confidence in building management can erode, and lease renewals may be affected. Reliable commissioning protects both the asset and the owner's relationship with tenants.

Three actions owners and facility leaders can take

• Require a commissioning plan before sign-off. Put it in the contract before construction begins, rather than treating it as a closeout afterthought.
• Make training and documentation deliverables. Require practical operator training and current records—not just a binder on a shelf or a brief walkthrough.
• Schedule a post-occupancy audit. Review performance six to twelve months after handover, when real operating conditions have had time to expose issues.

The commissioning plan should provide staged testing: verify infrastructure when installed, integration when systems are connected, and performance under load when the building is occupied. Operators should participate throughout. Owners should also ask contractors and vendors hard questions before sign-off; the project team may be ready to close out, but the owner will live with the building for years.

The real test starts after opening

Commissioning is not a technical checkbox. It is a business process for protecting investment, tenant experience and reputation. The meaningful test is not only whether the building works on opening day, but whether it continues to work as people, equipment and connected systems place real demands on it.

Listen to the episode for the full discussion of integration testing, operator readiness and practical handover expectations.

Why a building can pass commissioning and still fail its occupants

A new building opens, tenants move in, and the first problems appear almost immediately. The HVAC cycles erratically. Wi-Fi drops during a meeting. The systems passed their tests, yet the people who depend on them are already frustrated. This is the commissioning gap: the difference between systems that work on paper or under controlled test conditions and systems that perform reliably in a real, occupied building.

For property owners and facilities leaders, that gap is more than a technical inconvenience. It can mean emergency calls, delayed repairs, disrupted tenant operations and a loss of confidence in building management. The episode's central lesson is that closeout must prove more than component-level operation. It must demonstrate that systems work together, that they can handle actual conditions and that operators know how to manage them.

What commissioning is meant to verify

Commissioning is the process of verifying that systems such as HVAC, electrical, network and security are designed, installed and functioning in line with the owner's requirements. The trouble comes when verification is treated as a set of isolated checks rather than a test of the building as an operating environment.

A system may perform correctly during a scripted test and still be unprepared for full occupancy. HVAC might be tested with only a few people in the building, not the heat load of a full tenant population. A network might be tested with a few devices, not the hundreds that connect on move-in day. If the test never puts the system under representative demand, a pass result can provide false confidence.

Buildings are interconnected environments. HVAC, building automation, fire alarm, access control, network and other systems can affect one another. A project can have capable contractors and vendors, each completing work in their own lane, while no one validates the connections between those lanes. The low-voltage vendor, IT team, security integrator and general contractor all need to coordinate around shared dependencies. For instance, access control traffic depends on network provisioning, and a building automation system may depend on correctly configured IP addresses.

Integration is where hidden failures surface

The episode describes a building automation system in which every point, alarm and schedule had been verified. What had not been verified was the system's integration with the fire alarm. Three months after handover, a minor fault in an air-handling unit triggered a fire alarm sequence that shut down the air-handling units. The building began pressurizing incorrectly, doors became hard to open, and the team had to respond to an emergency caused by an issue that should have been a straightforward service request.

This illustrates why a system-by-system checklist cannot be the whole commissioning plan. The building automation system had been tested. The fire alarm had its own role. The failure was in the way their actions interacted. Similarly, access control and fire alarm systems can conflict if one calls for doors to lock down while the other calls for them to open. The integration itself needs to be tested, not assumed.

Testing and coordination are complementary. Testing verifies that individual systems behave as intended. Coordination verifies that the systems exchange information and respond together as expected. One without the other leaves blind spots.

Operator readiness is a performance requirement

Even a technically sound system can become a practical failure if operators are not prepared to use it. A brief vendor walkthrough does not necessarily give building staff the ability to respond to changing conditions or troubleshoot everyday issues. The episode recounts a new chiller plant whose operators received a standard walkthrough but were not shown how to adjust set points during a heat wave.

When June temperatures reached 95 degrees, the chiller was running at 50% capacity because nobody knew how to override the schedule. Tenants reported warm offices, and the team waited two days for the vendor to become available. This was not simply a question of whether the chiller had been commissioned. The handover had failed to equip the people responsible for the building to operate it in the circumstances they faced.

Operators should be involved from day one and take part in testing, rather than being treated as recipients of a final presentation. Training should help them understand the controls and practical responses they will need in their work. The goal is not to check a training box; it is to make sure the owner's team can run the building without being left helpless when a vendor is unavailable.

Keep documentation alive after handover

Documentation is another part of operational readiness. As-built drawings may already be outdated by the time they are delivered. System changes, overrides and updates need to be recorded in living documents that operators can rely on later. Otherwise, troubleshooting in year two, three or five can become guesswork.

Undocumented overrides are a particular first-year risk. Someone may change a setting to address a temporary problem and fail to record it. Months later, that setting remains active and contributes to an entirely different issue. Without a record, staff may not know what changed or why. The episode also warns about unvalidated alarm points: a system may appear to monitor critical equipment, but nobody has verified that the alarm actually activates when it should.

These failures may eventually lead to a repair, but the business consequences can be broader. When building problems disrupt a tenant's work, the tenant may question whether the property is being managed effectively. Trust is difficult to rebuild, and the discussion notes that leases have not been renewed over this kind of experience.

Build commissioning into the project from the start

A useful commissioning process begins before construction. The plan should be written into the contract before work starts, so expectations and responsibilities are clear rather than negotiated under closeout pressure. It should set out staged testing at three points:

• When infrastructure is installed: Verify the underlying infrastructure as each phase is completed.
• When systems are connected: Test the integrations and dependencies between systems, not only the individual components.
• When the building is occupied: Test under load, with the people, heat and network traffic that reflect actual use.

This staged approach is more informative than a last-minute round of ideal-condition tests. It also makes it easier to identify problems while the relevant teams are still engaged in the project. Operators should participate in these phases so that testing reflects both technical requirements and day-to-day building needs.

Three practical steps for owners and facilities leaders

First, demand a commissioning plan before signing off. Make it a contractual requirement, not an optional activity added at the end. Ask how systems will be tested individually and together, and how performance will be evaluated under real occupancy.

Second, require practical operator training and current documentation as project deliverables. A binder left on a shelf does not ensure readiness. Staff need to understand how to operate the systems, and records must reflect the changes made during construction and handover.

Third, schedule a post-occupancy audit six to twelve months after handover. Real operating conditions reveal issues that a project team may not see during construction. Catching problems during that period gives the owner an opportunity to address them before they become more expensive or damage tenant confidence.

Owners should not be afraid to push back on contractors and vendors who are eager to close out the project. The project team may move on, but the owner and building operators will live with the building for years. Asking hard questions before sign-off is a way to protect that long-term responsibility.

Measure success beyond opening day

A building is not proven by a certificate, a ribbon cutting or a stack of test results. Its real test comes when occupants arrive, systems interact and operating conditions change. Commissioning that includes staged testing, cross-team coordination, operator participation, usable documentation and a post-occupancy review helps close the gap between what was designed and what actually works.

That is why commissioning should be understood as a business process as well as a technical one. It protects the owner's investment, supports tenant experience and safeguards the property's reputation. For more practical discussion of building systems and workplace technology, listen to this episode of Built, Wired & Secured.