Sustainability certification for buildings
Construction projects typically aim for one of three primary sustainability certifications:
- DGNB, Green Building Council
- BREEAM, Building Research Establishment
- LEED, Leadership in Energy and Environmental Design
All three focus on making buildings more sustainable, but their approaches are distinct. Each certification programme also has different emphases, since they were developed in different countries.
That said, all three programmes reward developers for using commissioning to varying degrees.
In the United States, commissioning was implemented during the energy crisis of the 1970s, as it was discovered that commissioning resulted in improved energy efficiency and operational processes. This is shown in the illustration below:
DGNB and the commissioning process
DGNB imposes explicit Cx process requirements in section PRO2.3. The DGNB guide's goal is to promote efficient handover of the finished building and to ensure that its installations function correctly and in an energy-efficient manner.
The DGNB requirements are linked to the UN's Global Goals for sustainable development. The commissioning process falls under Goal 7, "Affordable and clean energy", and Goal 12.2, "Sustainable management and use of natural resources".
The 2020 edition of the DGNB manual imposes DS3090 and ASHRAE Std202 requirements in a slightly stricter approach to Cx.
p>The commissioning requirements are divided into two groups: "Measurement and recording, revision, and performance testing" (up to 50 points) and "Commissioning" (up to 60 points).
Measurement and recording, revision, and performance testing
These requirements are related to conducting functional and performance testing.
- A plan must be developed for measuring and monitoring technical installations, ensuring that the number of measurement points is sufficient to test each installation's functionality. All system elements are subjected to functional testing per the requirements in the Danish Building Regulations. (30 points)
- Additionally, cross-disciplinary and system-orientated performance tests beyond the scope of the functional testing requirements in the Danish Building Regulations are performed. (50 points)
Cx Prerequisite: Fundamental commissioning
Fundamental LEED Commissioning is a prerequisite. These LEED activities in the commissioning process must be met in the project to earn credits in the Energy and Atmosphere category.
Fundamental activities
Fundamental Commissioning requires all of the following commissioning (Cx) tasks for mechanical, electrical, plumbing, and renewable energy systems and assemblies in accordance with ASHRAE Guideline 0-2013 and ASHRAE Guideline 1.1–2007 for HVAC&R Systems.
- Review the owner’s project requirements (OPR), basis of design (BOD), and project design
- Develop and implement a Cx plan
- Confirm incorporation of Cx requirements into the construction documents
- Develop construction checklists
- Develop a system test procedure
- Verify system test execution.
- Maintain an issues and benefits log throughout the Cx process
- Prepare a final Cx process report
- Document all findings and recommendations and report directly to the owner throughout the process
CxA qualifications
A qualified commissioning authority (CxA) must be appointed to manage these commissioning activities in LEED by the end of the design development phase. Often the CxA will be using a software solution to manage the process.
In addition to the above requirements during project design and construction, the team must prepare and maintain a facilities requirements and operations and maintenance plan, including the following.
- A sequence of operations for the building
- The building occupancy schedule
- Equipment run-time schedules
- Setpoints for all HVAC equipment
- Set lighting levels throughout the building
- Minimum outside air requirements
- Any changes in schedules or setpoints for different seasons, days of the week, and times of day
- A systems narrative describing the mechanical and electrical systems and equipment
- A preventive maintenance plan for building equipment described in the systems narrative
- A commissioning program that includes periodic commissioning requirements, ongoing commissioning tasks, and continuous tasks for critical facilities
Cx credit opportunity: Enhanced commissioning
Project teams can earn LEED credits through additional commissioning-related tasks in Enhanced Commissioning if all of the above Fundamental Commissioning requirements are met.
Enhanced LEED Commissioning has two options for credits: Option 1 - Enhanced Systems Commissioning, worth 3-4 points, and Option 2 - Building Enclosure Commissioning, worth 2 points. If both options are achieved, a total of 6 points can be earned through Enhanced Commissioning.
Option 1 - Enhance systems commissioning
Option 1 - Enhanced Systems Commissioning is comprised of two separate paths.
Path 1: Enhanced Commissioning is worth 3 points and requires the commissioning authority to complete the following.
- Review contractor submittals.
- Verify inclusion of systems manual requirements in construction documents.
- Verify inclusion of operator and occupant training requirements in construction documents.
- Verify systems manual updates and delivery.
- Verify operator and occupant training delivery and effectiveness.
- Verify seasonal testing.
- Review building operations 10 months after substantial completion.
- Develop an on-going commissioning plan.
- Include all enhanced commissioning tasks in the OPR and BOD.
Path 2: Enhanced and Monitoring-Based Commissioning is worth 4 points if the team develops a monitoring-based plan to measure and evaluate the performance of energy- and water-consuming systems and all of the Path 1 requirements are satisfied.
The procedures and measurement points in the monitoring-based plan must include the following.
- Roles and responsibilities
- Measurement requirements (meters, points, metering systems, data access)
- The points to be tracked, with frequency and duration for trend monitoring
- The limits of acceptable values for tracked points and metered values (where appropriate, predictive algorithms may be used to compare ideal values with actual values)
- The elements used to evaluate performance, including conflict between systems, out-of-sequence operation of systems components, and energy and water usage profiles
- An action plan for identifying and correcting operational errors and deficiencies
- Training to prevent errors; planning for repairs needed to maintain performance
- The frequency of analyses in the first year of occupancy (at least quarterly)
Option 2 - Building enclosure commissioning
Option 2 - Building Enclosure Commissioning is worth 2 points, bringing the total number of possible points for Enhanced Commissioning to 6 points. It can be completed with Option 1 or separately.
The team must fulfill the requirements of Fundamental Commissioning as they relate to the building's thermal envelope and complete the following commissioning tasks for the building's thermal envelope in accordance with ASHRAE Guideline 0 and ASTM E2947-16: Standard Guide for Building Enclosure Commissioning.
- Review contractor submittals
- Verify inclusion of systems manual requirements in construction documents for enclosure systems
- For specialty enclosure systems with controls and automation:
- Verify inclusion of operator and occupant training requirements in construction documents.
- Verify systems manual updates and delivery.
- Verify operator and occupant training delivery and effectiveness.
- Verify seasonal testing.
- Review building operations 10 months after substantial completion.
- Develop an on-going enclosure commissioning plan for maintenance, renewal, and revitalization cycles.
Frequently asked LEED commissioning questions
What is a LEED commissioning authority?
A LEED commissioning authority (CxA) is responsible for leading a project's entire commissioning process, from design to turnover.
To be compliant with LEED requirements, the CxA must have the following qualifications:
- Have commissioning process experience on at least two building projects with a similar scope of work, from early design phase through at least 10 months of occupancy.
- Be an employee of the owner, an independent consultant, or an employee of the design or construction firm who is not part of the project's design or construction team, or a disinterested subcontractor of the design or construction team.
- For projects smaller than 20,000 square feet (1,860 square meters), the CxA may be a qualified design or construction team member. The CxA must report their findings directly to the owner in all cases.
Is commissioning a LEED requirement?
Commissioning is a LEED requirement in order to earn points in the Energy and Atmosphere category. To receive credits in this category, project teams must adhere to the commissioning provisions outlined in Fundamental Commissioning and Enhanced Commissioning.
While commissioning is not necessarily a requirement, it presents itself as an opportunity to earn up to 6 points toward LEED certification.
What is the difference between enhanced and fundamental commissioning?
Fundamental Commissioning is a LEED prerequisite that requires commissioning activities for mechanical, electrical, plumbing, and renewable energy systems and assemblies.
Fundamental Commissioning requirements must first be met to qualify for Enhanced Commissioning credits. Enhanced Commissioning is worth up to 6 points towards LEED certification. It outlines various requirements for Enhanced Systems Commissioning and Building Enclosure Commissioning.