Full-scale commissioning always starts in the design phase and includes at least one design review cycle. However, the concept of “design review” is overly broad, and it is important for the design review expectations of the commissioning professional to be objectively defined during the scope and fee development portion of a commissioning project.
There are various types of design reviews available in the design and construction industry. The most common, in alphabetical order, are as follows.
Commissioning. Focused on compliance with the Owner’s Project Requirements (OPR), controls and dynamic operation, systems integration, accessibility and maintainability, and energy efficiency.
Constructability. Focused on the feasibility, practicality, and efficiency of building the structure and installing the systems shown on the designers’ drawings within the project’s schedule and budget.
Coordination. Focused on confirming that coordination between trades has been worked out on the design drawings. For example, is there space above the ceilings, in the shafts, and in the mechanical/electrical rooms for all equipment, piping, conduit, and ducts to be installed without interfering with each other? Also, are the drawings consistent with respect to sizes and types of piping, ductwork, and conduit that end on one drawing and continue on another drawing?
Peer. Focused on the design engineers’ assumptions, calculations, and equipment selection. A peer review will also evaluate the sizing of ductwork, piping, and conduit.
Although these four focused review types have some inherent overlaps, for the most part they are unique and need to be understood as such. Asking a consultant to perform a peer review will not result in a constructability review; asking for a coordination review will not be the same as requesting a commissioning review, etc.
The required skill set and background of the reviewers are different for each of the design review types. In addition, the level of effort required to perform each review is different and essentially mutually exclusive of each other. The following table summarizes the expertise and background an owner would want when contracting for the different design review services. In addition, I have offered a very broad order of magnitude-type estimate of what the owner might expect to pay for each of the types of reviews as a percentage of a project’s total construction cost.
When soliciting and procuring commissioning services, owners need to determine the type of design review they want from their commissioning provider and manage expectations accordingly. These expectations should be articulated in the request for proposal and/or contract documents.
Knowing what the owner expects is important when selecting a commissioning team that can provide the desired skill sets. For example, if it is simply a commissioning design review, i.e., the default minimum level of review one should expect as part of a commissioning process, then the design reviewers should be commissioning engineers and/or facilities operations professionals with hands-on systems operations experience.
If the owner wants both a commissioning review and a peer review, then the review team needs to also have someone with substantial design engineering experience. That “someone” could be the same individuals with commissioning and/or facilities operations experience, i.e., they may have been design engineers at one time. However, their credentials should clearly differentiate between which past projects they designed and which past projects/buildings they commissioned and/or operated.