Hi LEED exparts,

All occupied spaces, not only regularly occupied spaces are required to meet requirements, according to the reference guide page 757. It is very stringent to follow that for all requirements of HVAC Background Noise, Sound Transmission, and Reverberation Time.

ASHRAE Handbook HVAC application (I can read only most current 2019 version) shows Design Guidelines for HVAC-Related Background Sound in Rooms: corridors and lobbies in office buildings, that are non-regularly occupied areas. Is my understanding correct that only conditioned spaces are required to meet the requirement? How about the spaces with exhaust fans only, like restrooms?

Only regularly occupied spaces are shown in the table 1 of LEED reference guide page 758, except mechanical equipment room and occupied area adjacency combination. Calculating the transmission class for adjacency combination of mechanical equipment room and occupied area seems reasonable, considering large sound caused in the mechanical equipment room. However do we need to calculate all other occupied spaces combinations such as circulation spaces and restrooms, finding next similar adjacency combinations? How about adjacency combinations of break room and hallway, restroom and hallway, stairwell and hallway and locker room and hallway for transmission class? I suppose it is sufficient enough to calculate transmission class ratings of only regularly occupied spaces and that adjacent spaces, is that right?

For reverberation time requirements, are we required to measure other rooms not shown in the table 2 of the reference guide?

Any explanations are appreciated. Thank you.