Hi,
This is because construction elements such as walls/beams/columns/etc are not typically required for a COBie ouput as they're not managed assets. Managed assets typically refer to elements such as Windows/Doors/Furniture/Mechanical Equipment/etc.
However if construction elements are required then you can change this within the COBie Toolkit, click on the options button at the top left followed by Object IDM (Ignored Entities) and set it None in the drop down menu.
After modifying the Object IDM (Ignored Entities) to None then all elements will be reported in the COBie spreadsheet.
