Based on comments when the stadium was built that it can be expanded by 12,000 if this was nessasary and only 3 of the 4 stands can be expanded.
As for Brighton the point was you showed us a few pretty pictures of 8,000 or so seats, if we can only expand to 44k then we can only expand by 12,000, 4,000 seats more than them. 12,000- 8,000 = 4,000, yes?