Envelope commissioning – for both new and existing buildings – is a critical tool for ensuring the ongoing energy performance of a building, and it can proactively support indoor air quality. Despite its importance, this strategy is not yet being regularly incorporated into building projects.
At Green Building Alliance, we want to see more teams undertake this process because the envelope can make or break the overall efficiency and durability of our buildings. Engaging in commissioning can also set our owners and operators up for success in maintaining high-performing spaces. Given recent reports that reducing energy and carbon emissions is more critical now than ever – and the proven relationship between our envelope and our energy demand – it is time to take another serious look at this topic.
To do that, I interviewed GBA board member Jeremy Snyder – whose team at BuroHappold designs high-performance facades and envelope systems (among many other things)– to help set some context around envelope commissioning. I hope you come away with a renewed excitement for taking a close look at this critical system within your building! Plus, at the end of the interview, you’ll find out where you can learn even more.
Many people are familiar with the process of commissioning building systems like electrical and HVAC, but the process of commissioning the envelope is not as well-understood. Can you walk us through what the process looks like?
Commissioning the building envelope, also known as envelope commissioning, is the process of ensuring that a building's envelope - which includes the roof, walls, windows, and doors - is properly designed, installed, and tested to perform as intended. This typically involves several steps, including:
Identifying the performance requirements for the envelope, such as insulation levels, airtightness, and water management.
Designing the envelope to meet these requirements, including specifying materials and construction methods.
Installing the envelope according to the design specifications.
Testing the envelope to verify that it meets the performance requirements, such as through air leakage testing or water penetration testing.
Commissioning the envelope, which involves verifying that the envelope functions as intended, and making any necessary adjustments or repairs.
Envelope commissioning is important because the envelope plays such a critical role in a building's energy efficiency, comfort, durability, overall performance, and building longevity.
“ Envelope commissioning is important because the envelope plays such a critical role in a building's energy efficiency, comfort, durability, overall performance, and building longevity. ”
At what stage of a new construction project should the envelope commissioning take place? Who should be involved?
Envelope commissioning is typically done during the design and construction phases of a new building project. It is important to involve a commissioning professional, such as a commissioning agent or engineer, who is trained in envelope commissioning and can ensure that the process is done properly. In addition, the design team, construction team, and building owner should also be involved in the envelope commissioning process, as they all have a role to play in ensuring the envelope is properly designed, installed, and tested. Engagement of all the stakeholders and steps in the process make for a successful building.
We know that a building’s envelope is critical for ongoing energy efficiency. How can commissioning the envelope support efficiency?
Commissioning the building envelope can support energy efficiency in several ways. First, by ensuring that the envelope is properly designed and installed, commissioning can help to prevent air leaks and other forms of envelope failure that can lead to energy waste. For example, commissioning can involve testing the envelope for air leakage and water penetration and making any necessary repairs to prevent these issues.
Second, commissioning can help to verify that the envelope is performing as intended, which is critical for maintaining energy efficiency over time. For example, commissioning can involve testing the envelope's insulation levels and airtightness and comparing the results to the design specifications to ensure that the envelope is meeting its performance goals. This can help to identify any issues that may need to be addressed, such as inadequate insulation or poor air sealing, and allow for corrective action to be taken.
Third, commissioning can also help to identify opportunities for improving the envelope's energy efficiency, such as through the use of more advanced materials or technologies. For example, commissioning professionals may be able to identify opportunities for upgrading the envelope to increase insulation levels or reduce air leakage, which can lead to significant energy savings over the long term.
Overall, commissioning the building envelope can help to ensure that the envelope is performing at its best, which can support ongoing energy efficiency and help to reduce energy costs.
“ Commissioning can help to prevent air leaks and other forms of envelope failure that can lead to energy waste. ”
How can envelope commissioning impact health and indoor air quality?
Commissioning the building envelope can help to ensure that the envelope is performing at its best, which can support good indoor air quality and promote healthy environments for occupants.
By ensuring that the envelope is properly designed and installed, commissioning can help to prevent air leaks and other forms of envelope failure that can lead to poor indoor air quality.
Uncontrolled air leakage into the building (infiltration) beyond specified tolerances could lead to increased moisture in and on building elements, possibly providing a condition for mold growth. Mold growth in buildings, depending on location, can shorten the life span of materials and, more importantly, negatively affect human health if the mold is near a breathing source or outdoor air intake location.
Leaking of air to the outside of the building (exfiltration) can cause humidity fluctuations outside the preferred tolerance of human comfort, which could compromise health and wellbeing. Air too dry or too humid can affect human health in a negative way.
Is it possible to perform retro commissioning on the building envelope of existing buildings? What types of actions can be taken by owners and operators to repair the envelope if something is discovered during the retro-commissioning process?
Yes, it is possible to perform retro-commissioning on the building envelope of existing buildings. Retro-commissioning is the process of evaluating the performance of an existing building and making improvements to enhance its energy efficiency, comfort, and overall performance. This can involve many of the same steps as commissioning a new building, such as identifying performance requirements, testing the envelope, and making any necessary adjustments or repairs.
If something is discovered during the retro-commissioning process that needs to be repaired on the building envelope, there are several actions that owners and operators can take. These may include:
Conducting a thorough assessment of the envelope to identify any deficiencies or areas for improvement.
Developing a plan to address any issues that are discovered, such as through repairs or upgrades to the envelope.
Implementing the plan by making the necessary repairs or upgrades to the envelope.
Testing the envelope again to verify that the repairs or upgrades have been successful, and the envelope is performing as intended.
Overall, retro-commissioning can be an effective way to improve the performance of the building envelope on existing buildings, and can help to enhance the building's energy efficiency, comfort, and overall performance.
“ Retro-commissioning is the process of evaluating the performance of an existing building and making improvements to enhance its energy efficiency, comfort, and overall performance. ”
GBA’s 2030 District team particularly encourages the use of envelope commissioning in existing buildings, since this process can have a huge impact on the ability of our 2030 District Property Partners to achieve their energy and carbon reduction goals. The team will be exploring this topic more in-depth at our upcoming Bridge to 2030 event on December 16 with Rob Hosken from Building Performance Architecture. At the event, Rob – whose work includes building envelope inspections and commissioning – will provide a primer on building science as it relates to the envelope, explain specific considerations for existing buildings, and share real-life case studies.
If you would like to learn more about this topic, please join us at our in-person Bridge to 2030 event! Advanced registration is required. You can also learn more in the Green Building Resources section of our website.
A big thanks to Jeremy Snyder for sharing these details to get us all thinking more about envelope commissioning!
Top image courtesy of RODNAE Productions on Pexels