As part of any standard inspection we always, for detached properties measure and check the size of the plot to ensure that it agrees with the deeds and, now on one occassion on the Zambra, the plot was under the agreed size of 1000sq mtrs
The first confusion is to establish the location of your actual boudary line form which to calculate the measurement
In fairness to the builder they again responded superbly, they checked the measurements, and confirmed that they had to extend the bottom boundary line right across by 30cm