Building Commissioning is the analysis, documentation and testing of all mechanical and electrical systems within a building to achieve optimum performance as defined by the building’s owner. Writing and following a Commissioning Plan ensures that all building systems work properly and work together as designed. Commissioning is an essential tool for optimizing energy performance and is now required by code for new construction in many areas.
Benefits of Building Commissioning:
Lower utility bills*
Improved equipment function
Reduced building operation and maintenance
Extended life of equipment
As there is more than one type of Building Commissioning, it is important to align your project goals and needs. Commissioning types include: Fundamental Commissioning, Enhanced Commissioning, Retro-Commissioning, Recommissioning and Ongoing Commissioning.
*BOMA cost data research claims that energy savings from commissioning is 20% to 50% and maintenance savings range from 15% to 35% as compared to a non-commissioned building.
Who performs Commissioning?
Commissioning is performed by a Commissioning Agent (Cx Agent), however it is a team effort and several parties must be active participants. The commissioning team for a new construction project typically consists of:
Contractor and Subcontractors
What steps are involved?
Define the Owner’s Project Requirements – The first and most important step is to define the owner’s operational goals for the building. This becomes a written document called the Owner’s Project Requirements (OPR). The OPR covers all aspects of the building from energy performance, to acoustics to life safety. The OPR later forms the Basis of Design (BoD) from which all design, construction and operating decisions stem.
Develop a Commissioning Plan – The Commissioning Plan establishes team member responsibilities and a framework for how energy systems commissioning will be implemented on a given project.
A typical Commissioning Plan includes:
Owner’s Project Requirements & Basis of Design
MEP As-built Documents
Operations and Maintenance Manuals
Retesting Commissioned Systems and Forms
Test Data Reports
Commissioning for LEED Certification (Fundamental and Enhanced Commissioning)
The LEED rating system requires that all new construction be commissioned. The type of commissioning required is called Fundamental Commissioning (a LEED Prerequisite which is mandatory). Fundamental Commissioning is not as extensive as Enhanced Building Commissioning but ensures that the base-building’s energy systems are designed, constructed and calibrated to operate at intended.
Enhanced Commissioning (a LEED Credit which is optional) requires that the Cx Agent is engaged early in the design process, which ensures that efficiency recommendations can be incorporated into the building’s design. Enhanced Commissioning also requires that the Cx Agent revisit the building after 10 months of occupancy to recommission the building before the owner’s warranty expires at 12 months.
The Fundamental Commissioning requirements include:
A review of the OPR and BoD (prepared by others)
Inclusion of Cx requirements in Construction Documents
Development and utilization of a Commissioning Plan
Review of Construction Documents at 95% completion
Review of contractor submittals
Development of an Operations Manual
Submittal of LEED forms to the GBCI review board
The Enhanced Commissioning requirements include (in addition to Fundamental Commissioning requirements):
Early engagement in the design process
Re-Commissioning of energy systems 10 months post-occupancy to review operation and resolve any identified issues
Retro-Commissioning or Existing Building Commissioning
The goal of Retro-Commissioning (RCx) is the same as commissioning for a new building. The Cx Agent will review the current systems in place, determine the owner’s goals and review annual utility bills (minimum 1-year of consecutive energy data). RCx offers the same benefits as commissioning… namely, to optimize all building systems in accordance with the owner’s requirements. A Commissioning Report highlighting any identified operational deficiencies is then presented to the owner for correction.
Benefits from Retro-Commissioning:
Reduced operational costs
Improved equipment function
Greater integration of various building systems and equipment
Resolution of problems that occurred during design or construction
Improved building operations and maintenance, thereby enhancing overall building performance
Identification and correction of operational deficiencies
The resulting simple payback periods are typically less than 2 years, often less than 6 months.
When a building has been in operation for several years and equipment is replaced, building systems are often installed without reference to the original design intent. A quick fix may lead to an out of balance system. Recommissioning can be defined as a revisit and in-depth study to ensure all systems are functioning as intended. Recommendations to adjust systems and correct issues are typical results of Recommissioning.
Continual Retro-Commissioning is referred to as Ongoing Commissioning. The Cx Agent revisits the building at a defined interval depending on the building type. Usually this is once every two to five years. During the Retro-Commissioning process, all new and existing equipment and systems are analyzed and any new occupant usage patterns are taken into account. Furthermore, the Cx Agent will study the utility metering and trend data from the previous year and compare against expected energy usage based on equipment testing. Following this comparative study, recommendations to achieve optimal performance based on the BoD and OPR are provided. The Commissioning Plan is then updated and delivered to the owner for implementation. Once energy saving measures are implemented, the operations staff is retrained on updated processes. The benefits are similar to Retro-Commissioning.
Selection of a Commissioning Agent (Cx Agent)
In addition to a professional license and/or certification (Registered Professional Engineer, Certified Energy Manager, etc.) consider a Cx Agent’s experience in the following areas:
Similar types of buildings
Familiarity of building systems
LEED project experience
Operations & maintenance training capabilities
Commissioning costs vary depending on building type, complexity of systems and building usage. Commissioning for a hospital with a central plant and photovoltaics will cost more than an office building with roof top air conditioners. Please contact us for a quote for your specific project and needs.