It is quite a common requirement particularly under BREEAM in multi-function buildings to require separate LCA reporting on each function. For example retail on the ground floor and office on the upper floor. In this instance, we need to split the quantities for each function proportionally by their NLA as a fraction of the whole building NLA. (Note if GFA is used there will be missing proportions for shared spaces, common areas and plant.)
The easiest way to do this is by building the model within a new template in the template library and then uploading the relevant proportion of that “whole building template” to the model.
Further detail is shown in the video below