High Rise Residential

So have you reviewed ASHRAE 62.1-2007 section 5.1 to ascertain whether you might be compliant? Seems like you have a shot at it now—but only ASHRAE 62 and your credit calculations will tell you for sure.

You may have resolved this already, but for the record it may be useful to point out that residential projects with no mechanical ventilation in the units can meet ASHRAE 62 with operable window areas that meet the necesary percentage of floor area (4% in 62.1-2004 I believe).
One hurdle we've faced is that occupied areas must be within 25' of the operable windows. Local codes may accept a condition where part of a room is within that 25' distance, but in a previous 2.2 CIR the USGBC ruled that all the occupied space must be within that 25' to comply as naturally ventilated.
In one case we were able to use a small booster/ transfer fan to circulate that air beyond that 25' distance, thus providing a combination of natural and (a little) mechanical ventilation.

David,

Was the transfer fan runnign continuous?

No, they are controlled by the occupant with a switch. This was to be consistent with operable windows and mechanical ventilation having user control.