Building Envelope Commissioning

The language used for BECx does make it pretty confusing. To get the 2 points for BECx requires that requirements in the EA Prerequisite for Fundamental Commissioning and Verification (as they apply to the building’s thermal envelope) be met, that the requirements of EA Credit for Enhanced Commissioning - Option 2 Envelope Commissioning be met, and that the commissioning process be performed in relation to energy, water, indoor environmental quality, and durability in accordance with NIBS Guideline 3 (Building Enclosure Commissioning Process). NIBS GL 3 is just that...a guideline, so I go by what LEED notes in the document and the reference guide and then perform those tasks in accordance with the Guideline. But where it gets confusing is that some of the tasks stem from Cx and aren't relevant to BECx. So this is my interpretation:

• OPR and BOD review
• Peer review (1 required but GL 3 recommends 3 reviews)
• Cx or BECx plan
• BECx specification
• construction checklists
• submittal review
• site visits to observe construction and testing
• Final report
• Warranty review
• Training
• Lessons learned workshop

Other items not listed by LEED but recommended include mockup construction and testing review and participation in preinstallation meetings.

I've also been wondering what people's experience has been with actual LEED reviews of BECx.  My thought is that you should only do the tests that are appropriate for your climate (eg. no spray rack test in a desert), but sometimes I get nervous about LEED reviewer's ability to make common sense judgement calls about situations that stray from the standard application.

Agree- the intent of testing is not to just do another test but to verify that the installation meets the OPR. So if the owner doesn't care about water tightness (which could be the case in a desert climate), then water infiltration testing would not be required. The BECxP should use his/her professional judgement about what kinds of tests and how many tests should be performed to verify that the construction meets the performance requirements. He/she must also be able to weigh in on (with the owner) which performance requirements are beneficial/appropriate, and which ones might not be, in his/her review of the OPR.

Thank you, Elizabeth.

1. Does anyone have RFP/brief to appoint the CxA for BECx?

2. I am working on a LEED V4 BD+C for Data Center, unfortunately Client has appointed a Commissioning authority who has no capability for additional 2 points BECx and now client wants Main contractor to appoint another CxA just for BECx. Will this be accepted by USGBC? please advise.

Thanks

It is standard practice for the BECx to be a different company than for the MEP systems. However, the same rules apply to their qualifications and independence. You give very little detail, but I would not think anyone working for the contractor would be acceptable or prudent. Why not have the BECx work as a sub to the CxA currently in place? My old firm did not have envelope skills, but we were able to team with some great companies over the years.

Thanks Elizabeth. You noted "Other items not listed by LEED but recommended include mockup construction and testing review and participation in preinstallation meetings." 

This testing can have huge cost implications and the credit information is unclear as to what is required. NIBS Guideline 3 is a bit jumbled and, while it has a lot of potential information, is neither clear nor helpful the way it is currently written.

How do we get 'bottom line' input regarding what is required? Based on NIBS G3 it sounds like either mockup or in-place testing is acceptable. What testing is required? Dynamic and static air and water infiltration? Thermal continuity? Air barrier continuity? Glazed systems? Opaque systems? Doors and entrances? The list can go on. The BECx folks I've spoken with often aren't sure what will or will not comply with the LEED credit. They have a laundry list of items that can be tested and are willing to do whatever the building owner is willing to pay for. 

Any clarity would be greatly appreciated.

It depends on your project's needs whether mock-up or on-site testing takes place. We are frequently involved in both - testing systems extensively in mockup before accessibility becomes an issue and mistakes are repeated. As a matter of fact, we witness spray rack tests in the Arizona desert. Tucson, AZ has monsoons with wind-driven rains as well as Winter rains. Makes for a pretty lush desert.

Note: v4.1 references ASTM E2947-16: Standard Guide for Building Enclosure Commissioning, rather than NIBS.

...and ASTM E2947-16 says: "While both levels of BECx require first installation mock-ups as a minimum requirement, enhanced BECx requires either a preconstruction laboratory mock-up or on-site free standing building mock-up to be tested."

Has anyone tried to use Passive House verification as a BECx agent? Do we really need to hire a seperate BECx agent for LEED and one a PH Verifier for PHIUS? 

I think it would depend on the qualifications and experience of the person with Passive House certification. Cx Providers have significantly different training and examinations than those required for PH credential. You might get lucky and find one who can do both but take a look at a site like BCxA.org to fully understand the Cx process.

In response to some of the above questions about specific requirements in the BECx, one of my project CxA's just received the following regarding a most recent project review specific to Field Water Testing outlined in Annex U of NIBS.  The credit was denied.  So it appears they are particular about all sections of the NIBS Guidelines being met.

“The documentation indicates that only thermal imaging occurred; however, NIBS Guideline 3-2012 Annex U states that field water testing should be completed for all projects and that projects must perform field water testing to provide assurance that the contract requirements are fulfilled. As the documentation confirms that water testing was outside of the commissioning scope of work, it does not appear that performance testing was included in the scope of envelope commissioning for this project. For future submittals, ensure that the required performance testing is included in the scope of envelope commissioning.  

The documentation does not demonstrate compliance.”

All other aspects and requirements were met except for the Field Water Testing outlined in Annex U of NIBS.  For the same reasons others above have noted this was not performed as it adds considerable costs and is outside the typical scope and capabilities of our primary go to CxA Firms in the area.  It was also perceived to be met via thermal imaging and the other required tasks, submittal and mock up reviews, etc....

Would be ideal if anyone else has had luck putting together any sort of response that was accepted during Clarifications or any workaround language / reasons for exemption for this specific requirement as it is blocking those 2 needed points from being achieved.  For this project I believe we are too late to retroactively respond to pull it back but we have several other projects that are just kicking off with construction that were also anticipating and need those 2 additional points.  

Has anyone else recently received review comments for this or perhaps submitted BECx under the V4.1 one off credit upgrade from V4, since this thread topic is under V4?  Any additional info or other review comments/accepted clarification comments would be helpful!

I don't have a lot of experience with this credit, but my experience is that is does NOT require specific procedures/tests described in the NIBS guideline. 

The reference guide (under Further Explanation) states "The type of envelope and size of building will determine what tests are conducted and the equipment required" and the NIBS guideline also seems pretty clear that it describes a process and not a checklist of specific tests. I definitely don't get the sense that the annexes are enforceable requirements, but rather supplemental information. 

I would ask GBCI if this is something they consider a requirement for all projects going forward, or just one inconsistent review comment. Like I said I don't have a ton of experience with this credit, but I *do* have a lot with catching review comments that go above and beyond what's actually in the credit language and this feels like one of those!

If the OPR includes water penetration resistance criteria (which they almost always do unless water infiltration doesn't matter), then water penetration testing to verify performance should be performed. But I would think it depends on the OPR and not a default for all buildings.

I agree with Elizabeth.  The scope of performance testing is determined by the BECxP and the Owner, and is defined in the Commissioning Plan and Cx specs.  In my experience in the frozen desert of Alaska, there is very little value to the very expensive (for us because no local testing agencies) water penetration tests, since all of the moisture problems we see are from air leakage. In our market, robust design reviews, blower door tests, infrared thermography, and extensive air barrier inspections/coordination efforts are much more effective at delivering a high-performance enclosure, so that is what we focus on in our BECx planning. NIBS and ASTM are guidelines for the Owner and BECxP to use to determine appropriate verification measures; they are not set-in-stone requirements. The LEED Reviewer is mistaken and this should be challenged by your BECxP.

Hi Everyone, 

Does anyone have Building Envelope Commissioning report which I can use as a template? Your assistence is very much appreciated.

i  want Building Envelope Commissioning Report, too. ,,,,, We recieved the request to compensate  the report.