Even after the 50% construction documents review, CxA will not be required to meet again. Even then, it is useful to let the CxA know of the design progress. Include them on the weekly meeting-minutes mailing lists. Design changes may affect the commissioning plan, to be commissioned equipment list, and probably the commissioning scope.

Hotel and multifamily projects may have difficulty achieving this credit if they are naturally ventilated and have interior spaces that are further than 25 feet from an operable wall or roof opening. These projects might consider increased window areas, shallower floor plates, or using mixed-mode ventilation so that mechanically supplied outdoor can support areas outside the 25-foot natural ventilation boundary.

The CxA meets the design team to explain the commissioning scope and collaboration with the design and construction team. The CxA provides commissioning specifications to be included in the specification book and reviews 50% Construction Documents and specifications to make sure they are aligned with the OPR and include commissioning activities. The CxA reviews the construction bid submittals by prospective contractors.

Specifications eliminate potential change orders associated with “extra” work required for systems commissioning by sub contractors. These specifications inform the commissioning agent’s responsibility and how it will impact the sub-contractors presence on site. Poorly written specifications that do not include details would leave uncertainties and gaps in contractor’s expectations.

Natural ventilation systems may require a more robust and intense integrated design process, consisting of several focused workshops analyzing several alternatives. Computer modeling may be necessary to test various design alternatives to determine which is most effective and efficient.

Continue running ventilation calculations and develop flow diagrams to inform the design process and confirm credit compliance.

Case 2 - Natural Ventilation

Refer to the commissioning plan regularly throughout the project to understand the roles and responsibilities of all team members relative to completing a quality project. It is a valuable document and is regularly under-utilized. Additionally, the commissioning plan should be updated to include contractor information and a more specific and accurate scope once equipment has been selected during the design phase (if previously not defined).

Laboratory facilities generally require very high ventilation rates. Consider installing separate mechanical systems for lab spaces and other spaces to maximize return-air mixing. Other strategies may include using a heat exchanger to capture energy from laboratory exhaust, using low-flow or variable-flow fume hoods, minimizing ventilation rates during unoccupied times.

Specifications need to include commission details. If the CxA is not on board by this point, refer to standard commissioning specifications to ensure it is included in the bid package.