Gross Internal Area is the internal area of the dwelling measured to the internal face of the perimeter walls.
I am trying to get GIA for flats. I would like to use room flat reference parameter to sort flats, then combine them together and then get GIA for each flat.
I can easily sort room by flat reference to group them. Not sure about step to combining rooms together into one big to read interior area at wall finishes for perimeter.
Second option is to generate AreaPlans from this combine rooms.
I am sure many people did this and there have to be already some easy way to get there.