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The LEED Commissioning Process for Buildings in BC

(excerpts from an article published in the "Info Exchange" publication of May 2011)

LEED was introduced to us several years ago and has been gaining momentum ever since. Currently, there are several hundred certified or registered projects in Canada alone. LEED has been the primary driver in motivating engineers and architects to build better, greener and more efficient buildings, resulting in some truly unique and inspiring designs. The Vancouver Trade & Convention Centre, the Olympic Athletes Village and several buildings at Langara College are to name a few.

But what is the down side of this desire to push ahead and build that state of the art monument to sustainability? In my experience, it has been the advanced level of complexity, particularly in the mechanical systems. Reliable and easy to control constant volume re-heat systems are a thing of the past and have no place in our energy efficient world. Geo-exchange systems, heat recovery heatpumps and radiant slab cooling and heating systems are becoming more and more common place.

How does commissioning fit into our green world and more specifically, what is LEED Commissioning? ASHRAE (from ASHRAE Guideline 0, The Commissioning Process) defines commissioning as:
"A quality-oriented process for achieving, verifying, and documenting that the performance of facilities, systems, and assemblies meets defined objectives and criteria".

From the California Commissioning Collaborative, commissioning is defined as:
"When a building is initially commissioned it undergoes an intensive quality assurance process that begins during design and continues through construction, occupancy, and operations. Commissioning ensures that the new building operates initially as the owner intended and that building staff are prepared to operate and maintain its systems and equipment."
For buildings registered under both the United States Green Building Council and the Canadian Green Building Council LEED certification programs the following systems, at minimum, must be commissioned:

HVAC&R systems and associated controls

Lighting controls

Domestic hot water systems

Renewable energy systems (e.g. wind, solar)

The USGBC and the CAGBC both have minimum commissioning requirements for any building applying for LEED certification. Fulfilling these fundamental commissioning requirements does not reward the building with any LEED points but is what is referred to as a Prerequisite. If this "Fundamental Commissioning" is not performed, the building will not be awarded any points, regardless of any green strategies that are being employed in the design. Currently, in order to meet the requirements of fundamental commissioning, the following steps must be completed

Designate an individual as the Commissioning Authority (CxA) to lead, review and oversee the completion of the commissioning process activities.

The owner must document the owner's project requirements. The design team must develop the basis of design. The CxA must review these documents for clarity and completeness. The owner and design team must be responsible for updates to their respective documents.

Develop and incorporate commissioning requirements into the construction documents.

Develop and implement a commissioning plan.

Verify the installation and performance of the systems to be commissioned.

Complete a summary commissioning report

In order to meet these fundamental commissioning requirements, the owner should hire or appoint a Commissioning Authority as early in the project as possible. LEED does allow for the Commissioning Authority to be a qualified employee of the Owner's project team or an employee of any of the consultant firms working on the project, provided they are not involved with the design of the project. KD Engineering strongly encourages Owners to hire an "Independent" Commissioning Authority from a company that specializes in building commissioning. It should be noted that the Commissioning Authority assembles and leads the commissioning team, writes the LEED Commissioning Plan and ultimately verifies the commissioning process, reporting directly to the owner. The commissioning process and results are documented in a commissioning report, left with the Owner at the end of the project.

Under the latest LEED rating systems (both CAGBC & USGBC), LEED points (2) can be achieved by hiring a Commissioning Authority to complete the "Enhanced Commissioning" credit requirements. These requirements include the following:

Prior to the construction documents phase, designate an independent Commissioning Authority (CxA) to lead, review, and oversee the completion of all commissioning process activities.

The CxA must conduct, at minimum, 1 commissioning design review of the owner's project requirements, basis of design, and design documents prior to the mid-construction documents phase and back-check the review comments in the subsequent design submission.

The CxA must review contractor submittals applicable relative to systems being commissioned for compliance with the owner's project requirements and basis of design. This review must be concurrent with the review of the architect or engineer of record and submitted to the design team and the owner.

The CxA or other project team members must develop the systems manual that provides future operating staff the information needed to understand and optimally operate the commissioned systems.

The CxA or other project team members must verify that the requirements for training operating personnel and building occupants are completed

The CxA must be involved in reviewing the operation of the building operations and maintenance (O&M) staff and occupants within 10 months after substantial completion. A plan for resolving outstanding commissioning-related issues must be included.

Pursuing the "Enhanced" Commissioning Credit has many benefits. By having the opportunity to review the design prior to the construction documents phase of the project, the Commissioning Authority will have a good understanding of the Owner's Project Requirements and will be able to ensure that the design team understands the commissioning process from the start. By reviewing the pre-tender design documents, the Commissioning Authority will be able to advise the design team on the preparation of the commissioning specifications and ensure that the Owner's Project Requirement's are being addressed in the design. Reviewing of the contractor submittals often turns up errors that if discovered during equipment check-out phase of the process, would be too late to address. The Commissioning Authority also oversees the creation of a Building Management or Re-commissioning Manual that provides the owner with any additional information not already included in the Operating and Maintenance manuals. This extra manual contains information required to maintain the building in a commissioned state or possibly, re-commission the building sometime in the future. The near-warranty end review by the Commissioning Authority ensures the involvement of the commissioning team right up to the end of the first year of building occupancy ensuring that any problems that come up after the building has been commissioned, are addressed by the commissioning team.

The commissioning team on LEED project is generally made up of the following:

LEED Commissioning Authority

Owner & Owner's Maintenance Staff

Design Consultants

General Contractor

Mechanical Contractor

Electrical Contractor

Controls Contractor

T.A.B. Agency

Tendered Commissioning Agents (Mechanical & Electrical)

It is important that this team refer to the LEED Commissioning Plan throughout the design and construction phases of the project and perform their duties as described in the plan. Commissioning is a team process and all team members must be committed to the process in order for it to be successful.

The LEED commissioning process does not and should not ever replace the Mechanical Contractor's or the Electrical Contractor's commissioning process. In the BC construction industry, commissioning of mechanical systems by a Consultant approved Independent Commissioning Agent, hired by the Mechanical Contractor, has been an industry standard since 1988. It was discovered some time ago that mechanical systems in new buildings, particularly the DDC controls, benefited from a thorough, structured commissioning process. A few well established companies, some with Testing & Balancing & Controls backgrounds, started providing commissioning services, working hard to meet the challenges that new and ever changing building system designs offered. This thorough "hands-on" testing of building systems gave the Consultant's confidence that their systems functioned as they had intended.

Currently, under the LEED commissioning model, it is allowable that much of what the Independent Mechanical Commissioning Agent provides, can actually now be done by the Contractor(s). The Commissioning Authority only needs to review or provide equipment commissioning checklists to the Contractors, and verify a sampling of the completed forms. Earlier versions of LEED suggested that repeatable functional test procedure check-lists that are critical to the success of any commissioning process should be prepared by the Commissioning Authority with the Commissioning Authority overseeing the actual testing. Newer versions of LEED still suggest that the Commissioning Authority oversee the testing, but also allow for a portion of it to be performed by the Contractors. Neither of these latter scenarios provides a comprehensive documented process. Without the hands-on testing by an approved Independent Commissioning Agent, problems will fall through the cracks and will result in system performance and operational failures. Omitting this key component in my opinion is a step backwards. LEED Commissioning should enhance our current industry standard commissioning process, not replace it.

The table below shows how the LEED commissioning process dovetails into the traditional mechanical commissioning process:

Some may say that it is redundant and possibly cost prohibitive to have a Commissioning Authority as well as Independent Commissioning Agents hired for a project. That will not be the case. For instance, a Mechanical Contractor that does not employ a Mechanical Commissioning Agent on a LEED project will ultimately spend more time satisfying the demands of the LEED Commissioning Authority. This extra time will need to be built into the Contractor's price. Consequently, a LEED Commissioning process that incorporates a Consultant approved, Independent Commissioning Agent will result in less time spent by the Commissioning Authority and a more thorough outcome.

At the final stages of any project, after the commissioning verifications have been completed and before the final commissioning report is prepared for the Owner, the Commissioning Authority oversees the training process for the Owner's maintenance staff and also reviews the Operating and Maintenance manuals that will be left with the Owner. It is critically important, particularly with highly efficient and innovative mechanical systems, that the Owner hire qualified maintenance personnel to operate and maintain the systems in their building. Building Operators that don't have a thorough understanding of how their systems are intended to function will not be able to properly maintain them. Ultimately, the Owner's requirements with regards to comfort and energy savings may not be realized.

LEED has brought the commissioning process to the forefront of our construction industry. Considering the costs of constructing and operating a new building in British Columbia, it makes good sense to properly commission it to ensure years of trouble free and energy efficient operation.

Paul Weverink, AScT., LEED AP is a Senior Technologist and the Commissioning Projects Coordinator for KD Engineering Co. in Burnaby, British Columbia