Sometimes, LPA officers can understandably be concerned by the fact that the area set out in different tables on the metric sheet don't appear to - at first glance - add up. However, the metric sheet does not require post-development area to match the pre-development area.
The metric sheet contains a set of error checks to make sure that the area values have been entered correctly. These can be found in tab 5 of the metric sheet, with four checks to investigate
Error Check 1: Should be green
Error Check 2: Should be green
Error Check 3: Should be green
Error Check 4: Should be green
If all of these are green, it indicates that pre- and post-development values have been entered correctly.