In a word, “very”.

Commissioning is a planned and integrated systematic process to ensure, through documented verification, that all building systems perform interactively according to the design intent. It is necessary for the commissioning process to establish and document the owner’s criteria for system function, performance, and maintainability; as well as to verify and document compliance with these criteria throughout all phases of the project. Commissioning procedures require a collaborative team effort and must begin in the pre-design phase, continue through the design and construction phases into the initial occupancy phase, including the training of O&M staff. Commissioning is the only process that assures a quality outcome. 

Building commissioning has become the preferred method for ensuring that the building systems are installed and operating properly and provide the performance envisioned by the engineer/designer. There are three categories of commissioning to choose from, whether you are working on a new or existing project:

Comprehensive Commissioning; Best Practices Commissioning; Continuous Commissioning

Based on the complexity of the building systems and the constant focus on energy supply and sustainability, continuous commissioning is especially advantageous. Continuous commissioning focuses on optimizing the HVAC system operation and control for the existing building conditions. Owners should insist on commissioning their buildings in the beginning in order to ensure design intent is met, that the building systems are functioning properly, the maintenance personnel understands how to operate and maintain the equipment and to establish a baseline model for future evaluations.

The established baseline criteria needs to be re-evaluated regularly to make sure that it is achievable under current building loads and usage. Over time the building conditions change (occupancy loads, utilization/purpose, construction changes, etc). Continuous commissioning assures that the owner keeps up with these changes and their building systems perform optimally with the changing criteria.

LEED Commissioning

Commissioning has long been an integral part of green building and the LEED green building rating system, and basic commissioning was built into LEED for New Construction as a prerequisite for certification. Commissioning is often misunderstood, especially among owners with no commissioning experience who often avoid the practice due to fears of initial high costs. The commissioning process offers benefits to both building owners and occupants through improved building performance and heightened occupant satisfaction.

ASHRAE Guideline 0-2005 defines commissioning as a quality-focused process that focuses on verifying and documenting that the facility and its systems and assemblies are planned, designed, installed, tested, operated and maintained to meet the Owner’s Project Requirements (OPR).  And while many believe that commissioning is for new buildings only, it can be applied to existing buildings as well, as long as stabilized occupancy conditions are in place. LEED for Existing Buildings: Operations & Maintenance includes a credit focused on continuous commissioning, which incorporates monitoring and analysis of building performance data between the regularly performed operation and equipment reviews.

Any added cost of commissioning is justified by the energy savings that can be realized through corrective actions identified in the commissioning process. LEED specifically focuses on this aspect by having a credit specifically regarding implementation of no-cost and low-cost measures related to energy efficiency identified in the analysis. LEED for Existing Buildings: Operations & Maintenance also provides the option of performing an ASHRAE Level II Energy Audits as the first part of the retrocomissioning investigation component for existing buildings. Upfront commissioning and energy audits costs are recouped within only one to two years and helps building owners avoid unnecessary operating expenses, which is critical in this economic environment.

If you’re involved with developing a U.S. Green Building Council (USGBC) LEED™ certified building, you are probably aware that building commissioning is an integral – and required – component of LEED™ certification.  LEED™ for New Construction (LEED-NC2.2 ) has two commissioning components, 1) Fundamental Building Systems Commissioning which is a prerequisite (i.e. must perform), and 2) Additional Commissioning (E&A Credit 3).