Our building is a 4 story mixed use residential project comprised of 4 floors with condominium units (52 units total), and retail space on half of the ground floor. Each of the condo units incorporates general exhaust, and is provided with a heat recovery unit, with 100% outside air. These units can only be operated with 100% outside air (there is no possibility of return air). We have followed the guidelines for EQ credit 3.1, Construction IAQ management plan - During Construction. Units serving the condo spaces will not be used during construction, and duct openings will be sealed with plastic. Our questions relate to the following statement, from the credit requirement: "After the flushout, replace the filtration media with new MERV 13 filtration media, except the filters solely processing outside air." Does this statement intend that after the pre-occupancy flushout period, MERV 13 filtration media is not required in air handlers which process 100% outside air? Or is the intent that MERV 13 filtration still be used on 100% outside air units, but new filters are not required after the flush-out period (that is, the 100% outside air exception refers only to replacement of flush-out filters)? Additionally, for units which will solely process outside air throughout occupancy of the building, is MERV 13 filtration media required during the pre-occupancy building flushout? The language both in the LEED 2.1 Reference Guide, as well as in the CIR responses to date, implies that the intent of the credit is to eliminate indoor air quality problems that occur as a result of construction, or originate within the building space and are re-introduced in return air. For this reason, it appears that 100% outside air units meet the intent of this credit without the use of MERV 13 filtration media. If this is correct, is there a minimum filtration requirement for 100% outside air units during building occupancy? Please clarify.