The spere truss divides the hall from the 'screens passage' beyond which was the kitchen, but that was replaced later by a 'solar'/private quarters; it doesn't need to span the whole width as does the central cruck pair

see also Martin Brettle's excellent gallery http://www.pbase.com/belvedere/lower_brockhampton & Mark Chambers http://www.pbase.com/46rossi/image/121954261 etc