Yes exactly midders I am just trying to pick up the pieces in major building projects in essex, nottingham, birmingham and york where the buildings do not match the approved plans or the workmanship (fire doors, fire stopping and fire alarms) is so dire that clearly nobody has ever looked at it. Problems include compartment walls gone AWOL, protected shafts with plasterboard only on the outside of the studding, jumbo studding fully exposed on the shaft side, fire door frames with 70mm gaps between the frame and the structural opening and fire alarms that dont work despite commissioning certificates or cause and effect written by people who have no inkling of what happens in a fire.
The developer in each case says tough, I have my completion certificate and it has been approved by BCO and fire service on consultation. You then find that the BCO, if he has actually visited site and not done a only desktop plan review (as is often the case especially with AIs) has only carried out a cursory tour.
As far as the Builder is concerned their responsibility under the contract has been completed by the issue of the completion certificate and my observations are dismissed as "purely the opinion of a consultant" leaving the occupier with a massive can of worms.