Basement carpark areas?

Walls of an underground garage typically are waterproofed against ground water, but some other barrier usually separates an unconditioned garage from the occupied, conditioned building. Besides providing thermal & moisture protection, this barrier typically blocks combustion fumes (and VOCs) from entering the occupied building. If your parking garage is unconditioned, open to the outdoors, and separated from occupied interior space, it is NOT interior space and is, therefore, exempt from IEQc4 VOC restrictions. See LEED Interpretation #1767: http://www.usgbc.org/leed-interpretations?keys=1767.

I have a similar question regarding technical rooms which are located underground on the same level as an underground parking. Can we assume that these spaces are exempt since they are not regularly occupied and they are separated from occupied spaces? What about vetical ventilation shafts where ducts and pipes are located? They are separated from the occupied spaces by concrete walls as well.

According to the IEQ Space Matrix, IEQc4.1 through IEQc4.4 each applies to mechanical and electrical rooms that lie to the interior of the weatherproofing system (see (http://www.usgbc.org/resources/eq-space-type-matrix). Likewise, ducts that carry conditioned air typically lie within the exterior weatherproofing system and within the conditioned envelope, as do pipes in many climates. As conditioned spaces, such shafts are typically included in a project’s building gross floor area (but unconditioned air shafts, pipe trenches, and chimneys are typically excluded). What makes basement garages different? LI#1767 excludes parking garages that are: . . 1. Unconditioned, . . 2. Non-regularly-occupied, . . 3. Open to the outdoors at all times (so not technically interior space), . . 4. Separated from the occupied interior by impenetrable walls (weather barriers). Since LI#1767 only addresses parking garages, I believe that this exception only applies to parking garages. If you wish to apply this exception elsewhere, you may wish to submit an inquiry to USGBC. Finally, LEEDonline Project Information Form 2 prohibits including parking area in the “Total Project Building Gross Floor Area.” LEED treats all parking as exterior space.

Thank you for your reply! In that case we will have to include technical spaces even though they are underground and not occupied. However if I understood well we can exclude unconditioned air shafts, is that correct?

Is this applied for multiple undergroung parking levels, as there is one level which is opened to the outdoors, but for the below levels, they are not opened to the oudoors, moreover there some conditined room in the parking for human use, so I think that the credit Low emitting material can not be excluded for the multiple parking level.