You can trust the Magic 8-Ball on this one: If you are involved in the early stages of a project space greater than 20,000 square feet, the outlook is good” that MEP commissioning (Cx) is likely required for that project. Because Cx can add value for the entire project life cycle, from pre-design through occupancy, the best time to begin discussing the need for commissioning is during the proposal phase.

The precedence for Cx requirements in most states is determined by the current energy code adoption of the locality for that particular project space. In 2012, the International Energy Conservation Code (IECC) was updated to include the requirement for commissioning for projects that met the following threshold from section C408:

Mechanical systems in buildings where the total mechanical equipment capacity is greater than 480,000 Btu/hr (40 tons) cooling capacity and 600,000 Btu/hr heating capacity.   (With certain exceptions for dwelling units and sleeping units)

As a rule of thumb, spaces greater than 20,000 square feet likely trigger the tonnage requirement, whereas spaces under 10,000 square feet likely will not. LEED projects being the exception – every LEED project will require Cx per LEED EAp1.

In more recent adaptations of the IECC (2015, 2018, 2021), Cx requirements were expanded upon to include more specific language on commissioning providers and additional system types as the industry is starting to recognize value of third-party quality assurance for energy consuming systems.

There are also Cx requirements detailed in NFPA 99 or ASHRAE Guideline 0, but for now we’ll stick with IECC given its nearly ubiquitous adoption into state-by-state energy code. Check out this link for a table of energy code adoption by state. Most states have adopted IECC 2012 or later, where there is a clear commissioning requirement. Keep in mind, California has its own set of guidelines where Cx is required for projects larger than 10,000 square feet.

Requirements aside, is it enforced? Concentrate and ask again” – that pesky Magic 8-ball strikes again! From the aforementioned link, you can see that several states list enforcement as voluntary. A quantum of states list enforcement as mandatory and in some instances, the local AHJ will not issue a permit without knowing the name of the Cx Authority, or won’t issue a TCO without seeing a preliminary commissioning report.

In summary, any project with more than 480 MBH (40 tons) of cooling or 600 MBH of heating (including domestic hot water) will require commissioning. Bringing this conversation up early can prevent surprise (overlooked) Cx requirements at the end of the project. In these instances it’s prudent not to leave the decision up to your favorite fortune-telling billiard ball, or to wait for local code officials to ask about it at permit phase or when looking for a CO. Without a doubt” look to offer the service early and look to Henderson Building Solutions to determine the best quote and scope of services.



About the Authors

John Pozzetta


Eastern Regional Manager
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