Today’s building energy codes are more stringent than ever, requiring design engineers and construction professionals to push the boundaries of innovative system design and construction. This, in conjunction with the growing complexity of direct digital controls, specialized building systems and the need for cross discipline integration, has brought commissioning to the forefront. Energy codes and energy design standards have recognized the importance of commissioning and the impact it has on improving building functionality, system optimization and overall energy efficiency.

Commissioning – often abbreviated as “Cx” – is the systematic and documented process to test and confirm a system’s performance against the original design intent, contract documents, and the owner’s project requirements. Such a process is critical with modern buildings, which depend on very high levels of digital controls with complex sequences that cannot be viewed or observed during a typical job site observation. Commissioning helps owners in a variety of markets move from the construction phase to the operation phase, making sure that all building systems are integrated and operating as per the original design.

The commissioning process has various stages and spans the pre-design, design, construction and post-construction phases of a project. Effective communication, coordination, and cooperation between all parties involved is essential, with the commissioning agent (or CxA) leading the team effort. Qualified commissioning agents are certified by a variety of nationally recognized commissioning organizations such as AABC Commissioning Group (ACG), Building Commissioning Association (BCA), Association of Energy Engineers (AEE), and ASHRAE.

<strong>Navigating commissioning requirements of codes, standards and LEED</strong>

Commissioning requirements vary depending on the adopted building code of the given state or municipality in which a project is located, as well as any standard or rating system being applied to the project. Commissioning is required by the International Energy Conservation Code (IECC), ASHRAE 90.1 building standard, and the LEED rating system.

The IECC was created by the International Code Council in 2000 for the establishment of minimum design and construction requirements for energy efficiency. To date various versions of the code (2009, 2012, and 2015) have been adopted by 48 states, several U.S. municipalities, as well as Puerto Rico, the U.S. Virgin Islands, Saudi Arabia and Abu Dhabi (see adoption map).

ASHRAE 90.1 is an international standard that provides minimum requirements for energy efficient designs for buildings except for low-rise residential buildings, and is an alternate compliance path for the IECC. ASHRAE 90.1 serves as the basis for many energy codes used throughout the country.

LEED – Leadership in Energy and Environmental Design – is a third-party green building certification program of the U.S. Green Building Council and the nationally accepted benchmark for the design, construction, and operation of high-performance green buildings and neighborhoods.

For purposes of this article, code versions IECC 2012 and 2015, ASHRAE 90.1-2010 and 2013, and LEED v.2009 and LEED v.4 are referenced.

How the commissioning requirements differ

In general, IECC 2012 and 2015 commissioning requirements are more defined and stringent than the requirements in ASHRAE 90.1, but less defined and stringent than LEED requirements. While all three require commissioning of HVAC equipment, temperature controls and lighting controls, IECC 2015 and LEED v.2009/v.4 include additional systems (see chart: Equipment to Cx). The codes/standards also differ on scope (see chart: Cx Scope Comparison) and on who can perform commissioning and functional testing (members of the design or construction team, members of the design or construction company, or an independent third party; see chart: Who Can Be the Commissioning Authority).

Commissioning highlights of each include:

ASHRAE: Although ASHRAE has published some of the most comprehensive guidelines and standards on the commissioning process in the industry (ASHRAE Guideline 0, Standard 202, Guideline 1.1., etc.), the commissioning requirements within ASHRAE 90.1 are minimal by comparison. Version 90.1-2010 requires commissioning of HVAC control systems “to ensure that control elements are calibrated, adjusted, and in proper working condition. For projects larger than 50,000 ft2 conditioned area, except warehouses and semi-heated spaces, detailed instructions for commissioning HVAC systems shall be provided by the designer in plans and specifications.” Lighting control devices and control systems – occupancy sensors, time switches and programmable schedule controls, and daylight sensors – are required to undergo functional testing “to ensure that control hardware and software are calibrated, adjusted, programmed, and in proper working condition in accordance with the construction documents and manufacturer’s installation instructions.” Lighting controls functional testing requirements are expanded in ASHRAE 90.1-2013. Per ASHRAE, functional testing of lighting controls should be provided by someone independent of the design or construction team.

IECC: IECC HVAC commissioning requirements are based on Btu capacity of the equipment within a building as opposed to square footage of the conditioned space, as used by ASHRAE and LEED. Per IECC, commissioning of a facility is required if its cooling systems capacity is greater than 480 MBH and if its heating systems capacity is greater than 600 MBH. Neither 2012 nor 2015 requires commissioning of systems serving dwelling and sleeping units in hotels, motels, boarding houses or similar units. IECC 2012 follows a traditional or “Cx Light” scope and does not include requirements such as Owner’s Project Requirements, Basis of Design and Pre-Functional Checklists – which are required by LEED. IECC 2015 added domestic hot water heating equipment as needing to be commissioned if the combined heating system and domestic hot water system’s capacity is greater than 600 MBH. IECC 2015 also expands upon the requirements in the code’s lighting controls functional performance section.

LEED v.2009: Fundamental Commissioning is an Environmental and Atmosphere (EA) credit prerequisite and covers HVAC, domestic hot water, lighting and daylighting controls, and renewable energy systems. The process includes a review of the Owner’s Project Requirements (OPR) and Basis of Design (BOD), incorporation of commissioning specifications, implementation of a Cx Plan, verification of the installation and performance of the building systems, and delivery of a Cx Report. Commissioning can be performed by a member of the design team if the project is less than 50,000 square feet, and can be done by someone from the design company not involved in the design if the project is more than 50,000 square feet. Enhanced Commissioning allows project teams to earn a credit by adding five additional tasks: Cx design review prior to 50% CDs, review of contractor submittals, development of a systems manual, verification of training for building operating personnel, and review of building operations within 10 months of substantial completion. Regardless of size, Enhanced Commissioning can only be provided by an independent third party provider separate from the design or construction team companies..

LEED v.4: LEED v.4 commissioning requirements are the most stringent of all. LEED v.4 built on v.2009 and expanded plumbing and electrical equipment commissioning scope and now references ASHRAE Guideline 0. Additional changes include the CxA needing to be brought on board “by the end of the design development phase” and requirements for the CxA to report results/findings directly to the owner. Fundamental Commissioning now also requires a Cx design review of the OPR, BOD and Design Documents including Building Exterior Enclosure review and requires a Current Facility Requirements (CFR) and O&M plan document be developed. For Enhanced Commissioning, two options are now available that include Envelope Cx and Monitoring-Based Cx depending on which option and path is chosen. All Enhanced Cx options/paths now require developing an on-going Cx plan as well.

While the above provides a summary of the requirements and differences in the commissioning sections of ASHRAE, IECC and LEED, project owners and designers should be sure to receive a comprehensive understanding of the commissioning requirements and process from their commissioning authority.

Learn about IMEG’s commissioning services or contact us directly.

* Although IECC 2012 allows the registered design professional or “an approved agency” to provide commissioning, it requires the “registered design professional” to provide evidence of commissioning prior to passing final mechanical inspection.

** IECC 2015 was updated to require the registered design professional OR “an approved agency” to provide evidence that mechanical systems commissioning was provided; however, the lighting controls section only lists the registered design professional as having to provide evidence that the lighting controls has been commissioned.

*** When required by code official, lighting controls functional testing can only be provided by an independent third party.