Existing Building Commissioning: “Surprise Management”

by Jeff Yirak, P.E., LEED AP BD+C, O+M of Wood Harbinger.

This article adapted from a presentation given at a WSSHE Puget Sound Chapter Energy Conservation seminar on September 17, 2014. View the PowerPoint version here.

Change is inevitable, and this is true for something as seemingly inanimate as a building. Small modifications, improvement, or changes over time compound until the facility is operating in vastly different conditions than called for by the original design. Some of these changes come from myopic upgrade projects, some from deferred maintenance, and some from the adjustments and tweaks made on a daily basis during normal operation. Existing Building Commissioning reveals important, up-front information about an existing building’s infrastructure, providing the insight needed for new designs and operations planning to avoid problems in the future.

What is EBCx?

According to the Building Commissioning Association’s “Existing Building Best Practices,” Existing Building Commissioning (EBCx) is a systematic process for investigating, analyzing, and optimizing the performance of building systems through the identification and implementation of low/no cost and capital intensive Facility Improvement Measures (FIMs) and ensuring their continued performance. Note we’re talking about FACILITY improvements and current FACILITY requirements; this is a holistic approach. The EBCx process assists in making the building systems perform interactively to meet the Current Facility Requirements (CFR) and provides the tools to support the continuous improvement of system performance over time.

The Five Phases of Existing Building Commissioning

The EBCx process is in many ways similar to individual healthcare, where the facility is the body and its Owner, users, and O&M staff the mind. When a problem is detected, there is a progression of activities by which the proper course of action to remedy it is applied. EBCx reveals and addresses the causes of problems, not just the symptoms, through a structured and rigorous investigative process, applied in five phases:

The five phases of EBCx

The five phases of EBCx

Planning: Like an initial consult with a doctor, this first stage gives the commissioning authority (CxA) an introduction to the historical facility conditions and establishes an understanding of the Owner’s goals for the EBCx process. There are three major components to EBCx Planning: the Current Facility Requirements (CFR) meeting, document review, and interviews. The commissioning authority works with the Owner and the facility operation and maintenance personnel on each part.

In the OPR meeting, the Owner and CxA set goals for the EBCx program, examine the facility requirements, and develop a commissioning plan. The CxA will review any existing documents, like as-builts, current O&M and training guides, and facility maintenance logs. Interviews with O&M staff and facility occupants/users are often the most useful aspect of the planning process, revealing information about the experienced conditions and revealing “symptoms,” such as a system being “undersized.”

Investigation: Just as a doctor may order tests or scans to reveal further information about the cause of a person’s symptoms, the CxA conducts a thorough facility investigation in order to accurately assess system performance and identify improvement opportunities. Through field inspection, data gathering, testing/trending, data analysis, the CxA develops a Master List of Findings report revealing the cause of the symptoms, and provides recommendations for implementing solutions via the Facility Improvement Measures (FIMs).

Implementation: Depending on the nature of the problem and the now-revealed cause, a doctor will discuss options for resolution, such as prescribe medications or recommend lifestyle changes that you can accomplish on your own, or recommend more intensive remedies that will involve other experts to see you through. In EBCx, this phase begins by selecting FIMs to address, and as we’ll discuss in more depth later, FIMS come in a hierarchy ranging from simple, low-cost fixes to major design/engineering undertakings. The actual implementation of FIMS utilizes the skills of the CxA and operations and maintenance staff, or engages any necessary design and construction professionals for replacements or renovations, depending on the nature and complexity of the FIM. Once the changes are made, the CxA will then measure and verify whether they indeed solved the problem.

Hand-off/Turnover: Like being released from the hospital, finishing a course of medication, or continuing new habits without the doctor’s supervision, the hand-off/turnover phase is the return to standard operating practice under the Owner and O&M staff, with the facility improvements in place. The intent of this phase is to ensure a systematic and smooth hand-off and transition from the commissioning process/team to the personnel responsible for operating and maintaining the building over its life-cycle (the O&M personnel). All necessary documentation, knowledge and systems are provided to the O&M personnel, who, at the end of the process, can demonstrate the effective use of these tools. In this phase, the CxA will update documentation and develop the Final Report, coordinate training and verify training effectiveness, compile or update the Systems Manual, develop persistence strategies, and conduct a Lessons Learned meeting with the Owner’s O&M staff and other EBCx team members.

Persistence: Just as you may go to the doctor for a yearly checkup, or continue monitoring how new habits are working for you, ongoing commissioning provides a check-in opportunity. System feedback review, such as Key Performance Indicators (KPIs), provides early identification of performance loss. KPIs can include IEQ monitoring, utility costs, and maintenance costs. O&M and CFR validation looks at whether the new O&M standard operating procedures maintaining persistence, and if the CFR is still relevant. If not, we may find out whether a new EBCx Process is required.

By Comparison: Other Types of Existing Building Commissioning

Existing Building Commissioning as described thus far is the application of the commissioning process to an existing building, with the primary focus of the process being the delivery of a facility that is in accordance with Owner’s complete CFR. It is an intentionally holistic look at the facility gauging multiple operational facets, not just, for example, saving energy. For a more targeted look at certain aspects, we have different processes:

Retro-commissioning (RCx): This is the application of the commissioning process to an existing building that has not previously undergone the commissioning process. It is often employed with utility public benefit funding, focusing primarily on reducing energy consumption and/or electrical demand in the facility.

Re-commissioning: This is the periodic re-implementation of the commissioning process to an existing building that underwent initial commissioning when originally constructed. It is performed either on a regularly occurring schedule (every 3 to 5 years is typical), or when building performance degrades; it is the answer to the “It’s not working, can you fix it?” phone call. I do this a lot. If the building occupancy or usage changes significantly, then we employ the holistic EBCx rather than re-commissioning.

Ongoing commissioning: This is the application of individual commissioning process-related activities on an ongoing basis to ensure that the CFR are being met and to support the continuous improvement of system performance. An Ongoing Commissioning Plan details how these activities and goals will be achieved.

Monitoring-based commissioning: A process variation of EBCx, Monitoring Based Commissioning employs remote energy system metering with trend log capability to identify inefficiencies in energy system operations, facilitate diagnostics, document energy savings, and ensure persistence of savings through ongoing re-commissioning. This process is becoming more mainstream as new fault diagnostic and predictive maintenance software becomes available.

Why Existing Building Commissioning?

Your project is finishes, record documents are received, and then the building stays exactly the same forever. Right? Operators never turnover and the original training you ensured they received is relevant forever, right?


In the real world, things happen, and in progressive environment, change is inevitable. There are certain changes that typically occur over time in a commercial facility that would lead to a need for EBCx: equipment is upgraded, there are operational changes, and O&M personnel leave. There are also common issues that arise: higher than expected utility usage, frequent comfort or noise complaints, and statements like, “It’s never worked right” overheard. In an attempt to address these problems, controls are overridden, sticky notes are written, and things are repaired with duct tape, both figuratively and literally. This is evidence of the operations and maintenance staff “making it work.”

These kinds of things are best addressed with EBCx, which by design reveals and addresses cause. High utility usage could be a symptom of overridden set points or schedules resulting in a “driving with the foot on the brake” kind of scenario. Frequent complaints could be a symptom of unresolved construction issues. “It’s never worked right,” may simply be inadequate maintenance documentation and training, either at original project turnover or because experienced personnel left the facility.

Common Findings

There are commonalities in the issues uncovered at different facilities. Previous projects leave equipment behind, or don’t document changes appropriately. “Unknown” or undocumented equipment doesn’t get maintained, and a result may not work correctly or may cause symptoms in a connected system. Workarounds and symptom fixes don’t address cause, so the problems persist. Here are some common examples of things we’ve found during our various EBCx projects:

Deferred Maintenance

Sometimes the line between “broken” and “not broken” is a little blurry. The flex joint below has failed, but the piping system it is in hasn’t. Another example might be a steam valve with a bucket underneath it. Sure, some water comes out, but the system is working fine. The EBCx FIM would recommend replacing these failing components now, during an organized and planned shutdown, rather than wait for the catastrophic failure that is potentially just around the corner.

Deferred maintenance. I’ve been meaning to fix that…

I’ve been meaning to fix that…

Abandoned Equipment

Projects that occur after the initial construction often add equipment, but sometimes they take away equipment or functionality as well. Abandoned equipment left behind may not seem like a problem, but the degree to which it is abandoned in place can be critical. The pump below obviously isn’t piped to anything, but what about the electrical connection? What about the controls graphic? If this pump is still on the controls graphic, what will the new operator do when he notices that it never turns on? The EBCx program will identify equipment that should be removed in the course of system integration, leaving the building with the complete systems it needs, and nothing missing or extra.

abandoned equipment

Sometimes when new equipment is installed, the old is simply abandoned in place.

Tribal Knowledge

Interviewing the maintenance staff during the planning and investigation phases is critical because they, better than any operator’s manual, know what it takes to make the building function. This knowledge is very valuable, but is often not part of the integrated operation of the facility. Set point overrides, systems in “Hand,” or “Off,” and notes to the operator are symptoms that the system’s automatic functionality has been disabled, usually to address a specific problem. A more holistic solution would be to address the root cause of the problem, rather than adapt the system to the problem.

Tribal Knowledge. Notes don't address the root cause of a problem

Notes like these may help O&M staff get by day to day, but it doesn’t address the root cause of the problem.

Lack of Integration

Sometimes addressing the root cause of the problem is more difficult than it needs to be. Modifications to existing building systems should focus on how the overall system will perform as a whole and not be myopic to the task at hand. When a fluid system is modified, the whole system may need to be rebalanced, not just the new work. New pressure or flow set points may need to be established for the whole system, since the system will function as a whole, and not just the sum of its parts.

lack of integration

While this may work, better integration will help streamline and organize the situation.

Lack of Optimization

In this picture, we have a handy note that indicates the system should be operating at 43 Hz, but the VFD shows it’s operating at 60 Hz. Why? Is there filter media in this system that has never been changed? Has a controls override been put in place that has never been released? If you were the design engineer on a new tenant improvement about to tap into what you thought was additional capacity of this fan, wouldn’t you want to know it was already maxed out? EBCx can help you avoid those surprises by bringing this information to the forefront.

not running at optimum

Knowing why conditions exist is as or more important than knowing what the condition is.


The Direct Digital Control (DDC) system can seem like a powerful tool, or a necessary evil. What do you do if you can’t trust the data on the DDC?

DDC System

Is the EF undersized, or is there a deeper root cause of the problem?

In this example, the EF is at 100% and can’t meet the pressure set point. It also looks like the pre-heat coil sensor is in the wrong place, and that we’re flowing about 65% OSA. No wonder the EF is maxed out at 100%. In this situation, it might seem like upsizing the EF is the required solutions. But since an “undersized” EF is not the root cause, the problem will persist.

The FIM Pyramid

Once the rigorous EBCx investigation is complete, and from it a comprehensive list of FIMS been generated, there is a hierarchical methodology for planning the implementation stage.

FIM pyramid

Most FIMS turn out to be simple fixes requiring little or no investment, with major capital projects being rarer.

Immediate adjustments: These are items like changing set points, removing overrides, fixing schedules, and are pretty obvious and inexpensive fixes. Adjustments like these could be made without employing EBCx, but doing so may not reveal why the conditions existed; why was override was made in the first place? It’s often possible that an override was a quick fix for a symptom, but without deeper investigation, the cause of the symptom will not be revealed, and the real problem will persist.

Maintenance activities: These are items like changing filters, adjusting water chemistry, repairing failed devices and equipment, and they are usually separate from a capital project. For example, what if we could change the way a system is operated in order to improve redundancy?

Capital projects: These are more costly items that would involve design and construction activity, such as replacing a failed chiller or installing condensing boilers in place of old or inefficient models. In our previous example, maybe we create a project that couples two systems, such that each system now had redundancy?

Interestingly, an EBCx investigation usually turns up mostly immediate adjustments and fewer capital project items, which is inverse to cost.

What is this going to cost?

Speaking of cost, the cost of the EBCx exercise is a common question, and it’s a valid consideration. But estimating costs for an EBCx program is not a clear-cut process; assigning an amount per square foot is not appropriate, as the reality will depend on the scope of the facility and the system(s) involved. The real question is value. What are you buying, and why? What’s the cost, in terms of lost productivity, when the office staff is uncomfortable because the facility isn’t’ performing as it should? What’s the value of avoiding an expensive change during construction when you find out the condenser water system can’t support the new equipment included in the design?

The cost of the improvement measures will be developed during the investigation, and this is why we propose the EBCx program be contracted in two parts. The first encompasses the Planning and Investigation phases, where the FIMs are developed; the list of FIMS selected for Implementation will describe the scope for the rest of the EBCx program under a second contract.

For some general perspective, the Lawrence Berkeley National Laboratory (LBNL) released a report in 2009 with a decade’s worth of commissioning experience assessment data, characterizing project performance and cost-effectiveness. Their findings show a median commissioning cost of $0.30 per SF for existing buildings and $1.16 per SF for new construction, revealing energy related-problems that, when dealt with, resulted in an average 16% whole-building energy savings for existing buildings, with a payback period of 1.1 years. These results, along with others, led LBNL to state that “commissioning is arguably the single-most cost-effective strategy for reducing energy, costs, and greenhouse gas emissions in buildings today.

What do you get?

Existing Building Commissioning is about capturing the full spectrum of a facility’s current operation and maintenance practices, and identifying and implementing improvements based on this comprehensive level of awareness rather than designing off assumptions. This awareness also provides an opportunity to augment training and tools for the facility operations and maintenance staff, which leads to improved operation, utility, and comfort. The purpose of EBCx is to uncover the root cause of problems and solve them at that level, rather than treating symptoms, which improves the facility overall by optimizing operations for redundancy, reliability, and indoor environmental quality (IEQ).

When do you want this information?

Unforeseen existing conditions are out there. When do you want to find out about them? An investment in Existing Building Commissioning to accurately establish existing system capabilities will pay big dividends in improved operation capabilities, as well as during construction, commissioning, and turnover of a renovation or tenant improvement project. Revealing the unknowns saves time and effort by reducing surprises. By leveraging the combined expertise of an experienced existing building commissioning authority and an informed Owner, the natural outcome is optimized continued operation and successful construction projects.


Follow Jeff on Twitter @JYirak_WH

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