How Commissioning Can Serve Your Design Team
by Jim Dirkes, PE, BEMP, BCxP
Back in the day, design architects and engineers were involved “cradle to grave” with new building construction. They designed the building, negotiated with the contractors, visited the site numerous times during construction, and conducted or supervised testing of everything to confirm proper installation and operation. That was the norm 50 or more years ago. But things have changed since then. Somewhere around the start of my career in the mid-70s, owners began trying to make design costs lower. As a result, the design firms started providing fewer services – what a surprise! Services left by the wayside included site visits and almost all post-construction testing and follow-up.
Meanwhile, the complexity of almost every design began to increase with the introduction of high-efficiency systems and digital controls. Now, there were many more ways for things to go completely off the rails or not work as well as intended. In the early 2000s, the US Green Building Council recognized this as a problem that adversely affected buildings' efficiency and made "commissioning" mandatory for buildings certifying to the LEED standards.
What is Commissioning?
The goal of commissioning has always been to close the gap between design intention and actual performance. Integrative design takes into account performance metrics beyond energy even. This gap closes when a knowledgeable party (preferably an independent third party) reviews and tests the building systems. Until recently, most building performance metrics focused solely on HVAC systems. Lighting controls have been added to that effort, mainly because codes mandate ever more complex control schemes that need verification. Envelope commissioning refers specifically to the function of exterior components of a building's design; the walls, windows, and roof can be an immense energy and moisture leak when not designed or installed correctly. Similar to lighting and HVAC systems, building envelope systems have integrated more technology and, in turn, become more complicated to maintain.
Even Excellent Design Teams Need Commissioning
We (Foresight) routinely work with talented and experienced designers. The same is true for our construction and trades partners. It's common to be involved with a team that not only is very talented but wants to do a good job and expects to be proud of their work. Many of these talented people experience tight time and budget constraints. The most significant role for commissioning agents is to act as “glue” in the design, construction, and trades team, closing and filling gaps of understanding that are overlooked or forgotten. Commissioning agents are generally not experts in every aspect of their work, but they lean on past project lessons and insightful questions to ensure everyone has equal understanding before construction. If the North arrow is the same for everyone, then it's more likely everyone will arrive at the same destination.
One consistently large knowledge gap in design documents is the “sequences of operation” for lighting and HVAC systems. Designers have a good idea of how their complex HVAC systems need to create comfort and efficiency but often underestimate how interdependent these systems are with other disciplines. Their “sequences of operation” are often very high-level descriptions that do not address practical details – and the practical details matter for actual performance and operation. While engineers bring a strong understanding of the interconnectedness of form and function, their expertise is not often called upon in the design phase. This gap is a prime place for commissioning to clarify and improve the original design through integrating engineering into the architectural process. Commissioning can have an even more significant impact when invoked early in the design process rather than after construction commences. Commissioning agents smooth communication between trades and troubleshoot potential construction and controls sequencing issues before the problems arise.
The Ongoing Benefits of Commissioning
When starting to commission HVAC about 15 years ago, I wondered whether I would add much value. With commissioning, we can't point to a complaints log or utility bill to measure the improvement that we've made – commissioning prevents those complaints or excessive utility bills from ever occurring! Even so, I am consistently amazed at how our commissioning efforts result in substantial tangible and intangible benefits that save money and headaches while improving equipment longevity.
5 Measurable Benefits of Commissioning:
Cost savings due to (actual) high-efficiency operation AND fewer headaches post-construction
Greater cooperation and knowledge-sharing among design and construction team members
Fewer complaints from the owner and occupants
Reduced preventative maintenance
Improved occupant comfort and air quality
You can’t afford NOT to commission your new construction project. Hire an awesome design team and make sure you have top-notch construction people. But don't assume that you'll be the first project in decades to be “successful” without also enlisting a commissioning team. You may not have hard metrics on “improvement,” but you don’t want to go through the headaches of resolving unforeseen problems or paying unnecessary bills that commissioning helps to avoid.
