After we started one of my projects, we came to know that there are many services underground which were not captured in the existing drawings of the area, these drawings dated back 12 years.

On a construction project which is cost and time bound we got a huge problem which could have led us to disaster.

A simple question from me to the MEP consultant saved all the stake holders. 

The question was 'Can the new valve chamber be made within the old drainage?'

After research the consultant agreed on the possibility; the old drainage was retrofitted to be the new valve chamber and drainage.