LEED v3 IEQ 3.2 What and how to measure?

Is Green Really Low VOC?

Just what is behind the LEED Green Curtain?

I do my very best to stay off the soap box when it comes to USGBC LEED and IEQ or more specifically IAQ.  I usually stay clear of this topic but I just can’t avoid speaking up once again.

LEED v3 for New Construction IEQ Credit 3.2   (page 64)


Intent of this credit isn’t to confirm, as you may think, the buildings actual use of the USGBC prescribed Low-Emitting Materials described in IEQ Credit 4.1, but to reduce indoor air quality (IAQ) problems resulting from construction or renovation and to promote the comfort and well-being of construction workers and building occupants. As described in the LEED documents page 66,

It may sound the same but until the IEQ Credit 3.2 becomes a Prerequisite it just a nice thought that looks good in print.

If the requirement did become a Prerequisite the sampling method would then need to be enforced.  Yes enforced.  The use of a MiniRae PID in a few locations doesn’t even come close the the methods described in the USGBC .Rating System Updated February 2011.

I have been working with LEED from the very beginning and I have provided LEED

3.2 testing in accordance with the Rating System many times.  I have provided many LEED and Indoor Air Quality presentations and discussions to USGBC Chapters and National Assoc. of Home Builders Chapters discussing these very issues.  The concern with the builders and general contractors is paying for the testing that may actually show that the building has an elevation in one or more of the USGBC Rating System Contaminant Maximum Concentration limits.  This actually happens much, much more that most would admit.  The result is that most simply ignore if not avoid the 3.2 Credit option 2 Air Sampling.

As a result of this avoidance, due to recent developments, and even though USGBC officially does not endorse one method over another,  the USGBC has allowed the use of handheld PID’s to measure TVOC’s.  The USGBC does this even though they have been made aware that using photoionization detectors (PID’s) to measure TVOC’s in buildings does not meet the minimum 4-hour sampling period required in the Rating System page 65.

This was an effort on behalf of the USGBC to encourage more contractors to actually pursue the 1 point in the entire USGBC Rating System that can confirm the use of the USGBC prescribed Low-Emitting Materials.  Something they are currently in serious need of confirming.

I continue to provide the LEED 3.2 point to my clients who are to actually wanting to earn the credit and confirm the buildings IEQ status using the USGBC required sampling methods.

I refuse to change my sampling protocols to those recently being used by others that require only a snapshot of the indoor environment using handheld PID samplers.

I choose not to provide anything less than the sampling methods that meet the USGBC’s Rating System requirements as described on page 65 of the LEED v3 LEED for New Construction launched on April 27, 2009, including an upgrade of LEED for New Construction under the suite of LEED 2009 rating systems. LEED for New Construction 2009 is served by the Green Building Design and Construction Reference Guide.

Pass or Fail the USGBC set their Standard.  I only measure the indoor environment according to their standard and encourage all others to do the same thing.

Go ahead take a peek at what is actually behind the curtain.


The USGBC sampling is described as follows.

OPTION 2. Air Testing

Conduct baseline IAQ testing after construction ends and prior to occupancy using testing protocols consistent with the EPA Compendium of Methods for the Determination of Air Pollutants in Indoor Air and as additionally detailed in the LEED Reference Guide for Green Building Design and Construction, 2009 Edition.

Demonstrate that the contaminant maximum concentration levels listed below are not exceeded:

Contaminant Maximum Concentration

•Formaldehyde 27 parts per billion

•Particulates (PM10) 50 micrograms per cubic meter

•Total volatile organic compounds (TVOCs) 500 micrograms per cubic meter

•4-Phenylcyclohexene (4-PCH)* 6.5 micrograms per cubic meter

•Carbon monoxide (CO) 9 part per million and no greater than 2 parts per million above outdoor levels

For each sampling point where the maximum concentration limits are exceeded, conduct an additional flush-out with outside air and retest the non-compliant concentrations. Repeat until all requirements are met. When retesting non-compliant building areas, take samples from the same locations as in the first test, although it is not required.

Conduct the air sample testing as follows:

•All measurements must be conducted prior to occupancy, but during normal occupied hours with the building ventilation system started at the normal daily start time and operated at the minimum outside air flow rate for the occupied mode throughout the test.

•All interior finishes must be installed, including but not limited to millwork, doors, paint, carpet and acoustic tiles. Movable furnishings such as workstations and partitions should be in place for the testing, although it is not required.

•The number of sampling locations will depend on the size of the building and number of ventilation systems. For each portion of the building served by a separate ventilation system, the number of sampling points must not be less than 1 per 25,000 sq ft or for each contiguous floor area, whichever is larger.

•Include areas with the least ventilation and greatest presumed source strength.

•Air samples must be collected between 3 and 6 feet from the floor to represent the breathing zone of occupants, and over a minimum 4-hour period.


John P. Lapotaire, CIEC
•Certified Indoor Environmental Consultant
•Microshield Environmental Services, LLC

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