To measure the cracks to any sort of degree of accuracy you need to fix the point of measurement and use very precise measuring tools as it usually happens over a long period of time.Great point. The surveyor I hired might have measured the gap and the sellers had their structural engineer look at it 5 months ago.
Is that long enough of a gap to measure any increases in crack size ?
You may have seen this kind of thing before:
That is unless it's really falling down where the different is rapid and noticeable.