Green Footprints Commissioning, Inc.

Sarah E. Maston, PE, QxCP, CPMP, LEED AP

Phone: 717-725-8231

Email Sarah










Commissioning: Existing Buildings (EBCx)

Commissioning can also be done on an existing building. In fact, it is suggested that a building be commissioned every 5-6 years. Over time, the building “drifts” away from his original design intent. This can happen due to a number of reasons, but lack of facilities staff training or high staff turnover often plays into it. Also, lack of documentation or lack of a complete sequences of operations, as well as change of usage within the building, can lead to inefficiencies and higher utility bills.

Commissioning an existing building is still a quality-driven, owner-directed process. The Commissioning Authority (CxA) typically acts as the Owner’s Project Manager (OPM) in an EBCx project. We work with owners to understand their concerns and goals for the project, which usually include energy reduction as a main priority. There could also be Indoor Air Quality (IAQ) or comfort concerns.
The commissioning authority CxA leads the owner’s team to develop the Current Facilities Requirement (CFR), which is similar to an OPR for new construction. A CFR development meeting is a great opportunity to bring all the stakeholders to the table, including End-users, Administrators, Operations and Maintenance (O&M) staff, and Contractors (if major renovation is a possibility) to decide what determines SUCCESS for the EBCx project. The CPR is also a living document, and should frequently be referred back to, throughout the project. The CFR, like the OPR, is the “Road Map” to success for an EBCx Project.
For existing building commissioning or energy reduction projects, many of the above tasks listed in New Construction are the same, but the scope of affected equipment may be less. 

  • CFR Development: Same premise as the OPR, but slightly different term. Current Facility Requirements (CFR) is a very useful document to have. This defines project success in an existing building. Knowing how the building currently operates, as well as the original design intent (if available), we can determine how far we have moved away from the design intent, or if the building usage has changed, it allows us to create new documentation reflecting the changes. The development of the CFR also promotes team buy-in by showing the O&M staff that you are there to help, not hurt.
  • Commissioning (Cx) Plan: It is still good to have a plan, or a project direction. Creating a Cx Plan helps to define the CxA’s scope of activities, as well as the roles that each team member plays in the Cx Process. In existing building, energy saving measures may be limited to distinct areas or systems. Having a Cx Plan helps keep everyone focused.
  • Basis of Design (by Design Team): If this is available, it is good information, but if not, further investigations will be required.
  • Design Reviews: Review any exiting documentation to determine original systems design intent & sequences of operation. This provides a baseline, from which changes can be noted. Also confirm existing documentation is accurate. Assuming documents are correct without verifying, can be disastrous.
  • ATC Coordination- most large facilities have an ATC contractor and most likely a maintenance contract. Meeting with this company will determine what the existing system is capable of, are their system updated that need to be installed, and can the company support the project requirements within their maintenance contract, or is an additional contract required. Best to get the answers early on, so costs can be accounted for.
  • Cx Specifications: Won’t be needed, unless renovation is large enough to go out to bid.
  • Submittal Reviews: Again, these Cx Reviews are different from Engineering Reviews. If the submitted equipment is different than the basis of design equipment, we look at coordination issues- dimensions, weight, electrical requirements, etc.
  • Automatic Temperature Controls (ATC) Coordination: In EBCx, usually the ATC Company in the building will get the new work. We have a meeting with the ATC subcontractor and the Owner to make sure that all sequences, safeties and alarms that are required by the Owner are included in the submittal, so there are no surprises at the end of the project.
  • Cx Kickoff Meeting: The intention of this meeting is to have all of the project team members who are active participants in the Cx Process (O&M Staff, Mechanical/ Electrical/ Plumbing Subcontractors, TAB Subcontractor, and ATC Subcontractor) come to the table to learn about the EBCx Process and their roles in it. We go over all of our forms and activities, so that everyone knows what to expect. This should be done early in the project, but not until all of the subs have been contracted.
  • Regular Site Visits: This does not necessarily mean every week. The intervals between visits should vary, based on the schedule of the project. For example, if the project has a 2 year time frame, weekly visits for the entire construction time will not be cost effective. Maybe ever couple of months for the first year, then monthly, then biweekly at 4 months from completion, then weekly, etc. As the Cx activities become more frequent, so should the visits.
  • System/ Terminal Unit Installation Mockups- may not be needed, unless there is a gut/ renovation being proposed, where there would be significant equipment replacement.
  • Installation Observations: Again, may not be needed, unless there is significant equipment replacement.
  • Pre-Functional or System Readiness Checklists- if some equipment has been replaced or even relocated, the contractor should submit checklists to indicate that the equipment is ready for Functional Testing.
  • ATC/ Testing & Balancing Coordination: This is one of the last activities to be accomplished before functional testing can proceed. It can be difficult if deadlines are approaching.
  • Functional Performance Testing: Depending on the scope of the project, the equipment may be tested according to original documentation, if the space usage remains the same, or new functional test documentation may be required if usage has changed.
  • O&M Document & Training Review: May not be needed; depends on scope of the project.
  • Cx Report: The Cx report has all of our documentation in one place for easy reference.
  • Off-Season Functional Performance Testing: We really can’t test a cooling systems in the winter. Humidity control cannot be simulated. Also, heating equipment should be tested in the colder months, in case there is a utility issue.
  • 9/10 Month Warranty Review: May not be needed, unless new equipment is purchased.
  • Trend Review: Commissioning often involves sampling in some building usages, to keep costs down. For example, in an office building, we may only test 10-20% of the terminal units. Trend reviews allow us to look over all the equipment, to determine if all systems are operating according to the design intent. Commissioning is also a “snapshot” in time of the systems operation. Just because a building is commissioned does not mean that setpoints or other variables won’t be changed after we leave. Trend Reviews are often a good place to start with Existing Building Commissioning.
  • Lessons Learned: There is always something to learn; always the opportunity to do something better the next time. We like to have a short meeting with all the key people at the end of the project to discuss what we did well, what we did mediocre, and what needs to be better next time.

So whether you are thinking of building a new building or your existing building is not performing the way you think it should, contact us. We will work with you and your team of professionals to turn over a building that operates efficiently, with complete documentation, and complete facility staff training for long term success.