Dear All,

I have a question regarding LEED v4 BD+C Core and Shell, EQ P1 Minimum Indoor Air Quality Performance and EQ C1 Enhanced Indoor Air Quality Strategies.

In  the context of an office building Core and Shell project, tenancy areas will be ventilated by an central air handling unit included in the scope of the Core & Shell, but the layout of these areas is not known (potential partitions and fit-out will be defined by each tenant).

According to LEED reference guide: “Make reasonable assumptions about the distribution of spaces and ensure that air handlers are capable of providing enough outdoor air for anticipated occupants and space types. For example, a typical buildout by an office tenant will include office spaces, corridors, and conference rooms. If these spaces are all served by the air handling unit, the system-level outdoor air must be sufficient to meet the outdoor air requirements of all three space types. If the occupancy is unknown, see Getting Started, Occupancy. “

The Owner has suggested, based on their experience in previous similar projects, suggested to consider the following mix in offices’ tenancy areas:

  • 90% open space;
  • 5% meeting rooms;
  • 5% breakrooms.

The above mix, considering default occupancies of ASHRAE 90.1-2010 for each applicable space type, originate average occupant density of 10,5 m2/occupant. This density is more conservative than the one indicated in appendix 2 as default for offices (23 m2/occupant).

Thus, can we consider that the mix of spaces indicated by the Owner are a reasonable assumption for the purposes of outdoor air flow rates determination?

Best regards,