Contiguous area requirement removed in the air quality testing section

Hi Deborah,

In July 2020, I asked the LEED Coach, and here was their response back then (note that I removed some area quantities and room names):

"It is correct that a four-story 40,000 square foot project with a single AHU would need a minimum of 2 air testing locations.  However, it is not correct that the project team can ignore how many floors an air handling unit serves when determining how many air quality testing location are required.  The 5/9/11 addenda referenced in your email was accompanied by another addenda on the same date which modified the credit guidance on page 466 of the reference guide as follows:

In the fourth paragraph, add in after "...the greatest presumed contaminant source strength", "Determine the number of ventilation systems serving the building. Then, determine if the individual floor plates served by each single ventilation system are larger or smaller than 25,000 square feet. If they are smaller, take at least one sample for every 25,000 square feet, or fraction thereof, served by a single ventilation system. If they are larger, take one sample per floor plate. For example, a 110,000 square foot building with ten 11,000 square foot floors, served by a single ventilation system, needs only five samples – one per 25,000 square feet (or fraction thereof) because each 11,000 foot floor plate is smaller than 25,000 square feet. However, a building with ten 30,000 square foot floors, also served by a single ventilation system, needs ten samples for the building because each 30,000 floor plate is larger than the 25,000 sq ft criterion."

See page 36 of the LEED v2009 BD+C Reference Guide Addenda Tables: https://www.usgbc.org/resources/building-design-construction-reference-g...

As stated in the credit language, "The number of sampling locations will depend on the size of the building and number of ventilation systems. The number of sampling locations must include the entire building and all representative situations. Include areas with the least ventilation and greatest presumed source strength."  Additionally, per the LEED v2009 EQ Space Type Matrix, "Sampling must be representative of all occupied spaces." (https://www.usgbc.org/resources/environmental-quality-space-type-matrix)  Please see the 'BD+C and ID+C Matrix' tab for detailed guidance by space type.  According to Addendum 100000931 (https://www.usgbc.org/leedaddenda/100000931) and LEED Interpretation 10222 (https://www.usgbc.org/leedaddenda/10222),  projects with standardized construction may sample one in seven identical spaces.  The spaces must be identical in construction, finishes, configuration, square footage, and HVAC systems.

It does not appear that the proposed locations for Project ID xxx meet these requirements or that a sampling protocol has been correctly applied.  Based on the information provided, there appears to be substantial variation in the size and ventilation rate within each space type in the project; however, only one space per space type is indicated as a sampling location. For example, science laboratories vary from xxx to xxx sqft and office spaces vary from xxx to xxx sqft.  Further, the spaces selected for testing do not appear to represent "areas with the least ventilation and greatest presumed source strength." For example, reception area xxx is indicated as a testing location, but the ventilation rate per person and per square foot in that space is higher than in Reception areas xxx and xxx. Likewise, computer xxx is a testing location, but the ventilation rate in this space is much higher than several other computer rooms in the project such as xxx, xxx, xxx, xxx, xxx, xxx, xxx, and xxx.

If the project team would like to reply back with a revised testing plan, we would be happy to review. Please also provide a brief narrative explaining how the testing locations were selected."