Originally Posted by sas
I was wondering from where the measurement of 7633 is taken with reference to?
This could be taken in two ways. It is either the height of the ridge from the ground level in mm. This will be shown as a dimension line with 7633 as the text. This way means that the difference in height between ridge and GL is 7633
Or it could be a spot height relating to the TBM, or datum height. In this case the height will be marked at the ridge, there will be similar heights at first floor level, and ground floor level, and also at ground level. This way means that the difference in height between ridge and GL is 7633 - (marked height of GL)
The difference in height between ground level and finished floor varies. 150 is an average. This height will be shown on the section. And as muffler said only the DPC needs to be 150 above GL. Grond level and floor level could, with the right detailing, be at the same level or say only 25mm apart.