Dear All,

We are working on a 6 storey residential project which pursues LEED certification under the BD+C: New Construction rating system.

According to the concept design, dwelling units will be naturally ventilated with VRF heating and cooling. As stated on the LEED reference guide and ASHRAE 62.1 2010, section 6.4, naturally ventilated spaces are required to include a mechanical ventilation system unless one of the following exceptions applies:

· Ventilation openings comply with Section 6.4 and are permanently open.

· Ventilation openings comply with Section 6.4 and have controls that prevent them from being closed during times of expected occupancy.

· The naturally ventilated zone is not served by heating or cooling equipment.

· The system is an engineered natural ventilation system approved by the authority having jurisdiction

Neither the above exceptions are feasible for our project’s dwelling units (and I am assuming for the vast majority of the project containing dwelling units as it wouldn’t be acceptable and appealing from the future buyers and/or tenants) nor installing fresh air ductworks is feasible in technical terms due to lack of space, etc.

Therefore, I would like to ask you whether dwelling units can be exempt from this requirement and only demonstrate compliance with ceiling heights, opening sizes, etc.

Thank you in advance.