Rating System

LEED BD+C: New Construction, LEED BD+C: New Construction, LEED BD+C: New Construction

Rating System Version

v2 - LEED 2.0, v2 - LEED 2.2, v2 - LEED 2.2

Inquiry

This question is in regards to the administrative alternative calculation method for this credit described in a credit ruling dated 01-11-2005. The method has since been rescinded but it can still be used by projects which were registered for LEED prior to October 15, 2005. The question is whether the calculation defaults published for LEED-NC v2.2 should be used or whether those mentioned in the ruling dated apply. For example, a 30 year life is mentioned as the default for equipment in the rescinded ruling, which is a bit of a stretch for small 5-ton HVAC units, but 10 years is used in LEED-NC v2.2 as a default unless documented otherwise. The difference in the default values is not trivial. The rescinded defaults can allow projects to use significantly more HVAC equipment of higher ozone depletion potential than would be allowed under LEED-NC v2.1 for non-HCFC equipment (assuming a maximum 15% non-base building exemption), or under LEED-NC v2.2 following its calculation requirements. For those projects which can still use the rescinded ruling can the USGBC please provide clarification on the defaults values to use, and what associated supporting documentation requirements should be provided for small sized equipment, if any. Also, a CIR ruling dated 11-04-2002 allows up to 15% of non-base building equipment to be excluded from the credit requirements. Does the alternative calculation method allow for the exclusion non-base building equipment up to 15% of total HVAC capacity, or must all equipment be included to show compliance?