The commissioning (CX) industry is waking up to the benefits of the Building Enclosure Commissioning (BECx) process. But what do building enclosure and envelope commissioning actually entail?
This article explores the value of BECx, using my experience on several projects that implemented BECx – and revealing the lessons they taught owners, consultants, and providers of BECx.
An Overview of Building Enclosure Commissioning (BECx)
Let’s start by establishing exactly what we mean by building enclosure commissioning: it is a quality assurance process that ensures the performance of the building’s enclosure aligns with the owner’s project requirements (OPR) and meets applicable codes, standards, and best practices.
All this is laid out in the ASTM International’s ASTM E2947-16 guidelines: a comprehensive set of best practices and procedures. Certified professionals use these guidelines to ensure design, construction, and operation of a building’s exterior envelope (i.e. it’s “enclosure”) meet key performance requirements – such as durability, energy efficiency, weather resistance, and indoor environmental quality.
There are other benefits, too, such as:
- Helping to identify and mitigate potential design or construction issues early in the project.
- Reducing operational costs and potential repair expenses over the building’s lifecycle.
But this is all very abstract; let’s look at how the process plays out in reality.
Three Lessons for Better Building Envelope Commissioning
Inspect the Mock-Up for Low Hanging Fruit
Most of us are used to looking at section views of plans and have learned how to recognize the detail in the section view as it translates into a completed system. Rarely do we get the opportunity to see a real section view in construction, except when the construction team is required to provide mock-ups of the building enclosure system. Mock-ups give the BECx provider a great head start reviewing how the contractors are actually going to install the enclosure system and also how that system will likely perform when completed.
For example, let’s say there was discoloration on the face of the stone due to the actual position of the weep being shallower than the designed position. Moisture was running down the brick face and onto the stone instead of dripping past the brick and falling to the ground. Correcting the installation mistake during mock-up was much less costly to the contractor and saved the owner years of operational headaches cleaning stone.
Expect the Unexpected—The Design May Need to Change to Accommodate Changes
Variations in product dimensions due to availability, substitutions, or mistakes are common in construction and affect every trade. Where there is some flexibility in dimensions with HVAC, electrical, or plumbing systems that are covered up in walls, there is little flexibility with the building enclosure because so much of the waterproofing’s effectiveness relies on dimensions.
Case in point is a project where we encountered a potential waterproofing issue with the windows. Due to a product substitution approved by the designer, the windows in a large K-12 project were no longer going to be flush to the brick. This required a field alteration to the design of the sill and wall applied air and water barrier detail.
Let’s say we can see a galvanized sill installed at the base of the window opening that interferes with the designed continuous air and water barrier. At this point in the project, the substituted windows were ordered and the field alteration had occurred at all of the more than 50 window locations. Sticking with the original design would have been costly and time consuming.
The contractor, designer, owner, and BECx provider worked together to come up with a solution and revised the design to incorporate the air and water barrier wrapping over the sill. This correction was incorporated into the project with no lost time or added cost because the team understood sometimes the design needs to change to accommodate reality.
Scheduling is Critical Because BECx Can Get Messy
I think the best lesson we learned implementing BECx is how important advocating for sequence and duration in project scheduling is for the project wellbeing and sanity of the team. BECx is becoming more popular in the industry, but is still less understood than general building commissioning. Construction teams, owners, and consultants need help from the BECx provider to get the right sequence of events and durations into the project schedule, but they themselves may not understand the process well enough to get it right.
For example, AAMA 501.2 testing of finished window enclosures requires the BECx provider to shoot pressurized water at the windows while being able to detect small leaks inside of the enclosure. Let’s say there’s an intrepid BECx provider hoisted above a window enclosure for water intrusion testing. The coordination effort to ensure the exterior of the window was installed well in advance of the interior finish out was imperative so the water intrusion testing could occur without damaging finishes.
Coordination with the landscaping contractor was also important so the scaffolding and water didn’t damage finished landscaping. This coordination occurred during pre-testing meetings well in advance of actual testing. It included all of the project stakeholders involved to make sure the goals and consequences of the water intrusion testing were understood. Precautions were also incorporated to minimize damage to finished surfaces and project delays due to repair.
To get the most bang for your BECx buck, make sure to include inspection of the enclosure mock-ups to find and correct issues early in the project, be prepared to make changes to the design to accommodate reality, and insist on tight sequence and duration scheduling involving all of the project stakeholders.
Put These Lessons into Practice with NEBB
If you can focus your time into these three lessons learned, you will help maximize some of the benefits of building enclosure commissioning: better quality of the installed product, finding and correcting issues before they largely impact cost or time, and helping the team work together to turn over a finished project to the owner.
Want to learn how NEBB certified professionals could help you do that?