To add the information about the layouts go to "Objects" => "My objects" => "Apartment Complex" => "Building" => "Section" choose Layout at the bottom of the page:
Upload 2D and 3D layout images (
png formats). It is also possible to upload the PDF file of the layout as well. It will be available for downloading or printing. If you don't upload PDF it will be generated automatically, for example.
You can edit the layout information that has been uploaded from Google Sheets:
After you finish editings press "Save".