Hi,
I’m working on a certification on a very old building with walls having an average width of 120 cm (4 ft). The GFA calculation is therefore extremely high in relation to the net floor area. I would like to know whether in this case too I have to calculate the GFA gross floor area from the external profile of the wall or is there a specification for cases like this. I would like to know if there are specific GFA calculation methods for this case or I have to measure from the exterior face anyway
E.g. the Italian regulations define specific cases precisely for buildings of this type
Thanks in advance,
Have a good day!
Dave Hubka
Practice Leader - SustainabilityEUA
LEEDuser Expert
494 thumbs up
September 2, 2022 - 7:52 am
Gross floor area must be measured from the exterior faces of the exterior walls, or centerline when connected to an adjoining building per the USGBC definition: https://usgbc.org/glossary#gross-floor-area-gfa
Calculations of occupiable space are taken from the interior face of the walls for the vent calcs as specified by ASHRAE 62.1.
Provide an explanation as to why Gross Floor Area will not match the total floor area listed within the MInimum IAQ Performance calculator when submitting the LEED application.
hint: areas / occupants counts will never match throughout the LEED application.
We prepared a standard narrative that explains this to GBCI, and is uploaded with each of our LEED applications.
Good Luck!
Filippo Weber
1 thumbs up
September 2, 2022 - 9:37 am
Hi David,
Thank you for your reply, so I assume you mean that there are no other way or further specification on how to calculate GFA.
Anyway, I will definitely follow your suggestion and also submit a narrative document in case datas does not match.
Have a good day,