Contractor’s Role During Predesign and Design Phases

Currently, the LEED requirements that should be considered as a minimum include the energy systems and water systems. (LEED v4 is strengthening minimum requirements as discussed.) A cost analysis that estimates the full cost of implementing the integrated LEED guidelines should be calculated and documented.

Finally, the construction documents (CD) are prepared. The contractor will work with designers, commissioning agents and sustainability professionals to make sure all LEED requirements are incorporated including material selection guidelines, waste management goals, training requirements, indoor air quality goals and commissioning requirements.

The drawings, templates and documentation required for LEED certification are submitted to the GBCI at this stage if a two-phase LEED certification approach is followed. Prior to GBCI submission, the design documents are reviewed by a LEED team comprising the commissioning agent, a LEED AP, contractor representative and design representative to identify and rectify potential problems in construction plans before construction starts.

Utilizing a commissioning agent

LEED Commissioning — Fundamental Commissioning involves review of OPR, BOD and the creation of a commissioning plan with specifications by a commissioning agent (CXA). In addition, the CXA should also verify the installation and performance of the systems to be commissioned and complete a summary commissioning report on project completion.

In addition to the scope of fundamental commissioning, the CXA is required to perform a design and contractor submittal review, verify that requirements for building operator training is complete, review building operations within 10 months of substantial completion and make a corrective action plan to resolve outstanding commissioning-related issues. The individual serving as the CXA must be independent. If the building area is less than 50,000 square feet, the CXA could be a member of project team with design or construction responsibilities.

Only energy systems are commissioned. Commissioning activities must be completed for the following energy-related systems, at a minimum:

• Heating, ventilating, air conditioning and refrigeration
  (HVAC&R) systems
• Lighting and day lighting controls
• Domestic hot water systems
• Renewable energy systems (e.g., wind, solar)

Though building envelope commissioning is not under the scope of fundamental or enhanced commissioning under LEED v4, a LEED project may earn one point under “innovation and design” for comprehensive envelope commissioning. The third draft of LEED v4 requires a qualified third-party commissioning authority (CXA) for projects exceeding 20,000 square feet. This is in contrast to the 50,000 square feet under LEED 2009. For buildings less than 20,000 square feet, a member of the design or construction team can serve as the CXA as long as he or she is not directly responsible for construction or design activities. LEED v4 also requires the CXA to verify the inclusion of a building envelope in OPR, BOD and CD.

To read the full story Part 2: Contractor's Role During Predesign and Design Phases, click here to download the Fall 2012 issue of Sustainable Construction.

To read Part 1: Sustainability and LEED: The Contractor is in the Driver’s Seat, click here.