If it took 2 years 6 months and 9 days , from foundations to handover of the 70000 seater Allianz Arena, how does it take 2 years to add approx 8000 seats to the Main stand?
Live environment
Residential area
Poor access
Working restrictions due to residents
Numerous issues with health and safety - congested working
Work would be in numerous phases
Many crane phases / relocation / re-rigs
Increase on incoming stat capacity?
Working with / tying into existing buildings and building levels is complex - unforeseen items, getting critical dims correct is harder
Risk of damaging existing stand which would be disastrous
Road closures, service diversions etc
....and that's after the Planning Dept have been satisfied
As Peter McGurk says
New stadium....
Potential to attack all four stands at once ( four different piling contractors, groundworkers, steel contractors etc)
Most likely packages would be phased so the pilers finish the first and leave for the groundworks etc - bit like phased housebuilding....but the options are far more open.
But, the main benefit would be that whilst the new stadium is being built you can chose working patterns which meets your financial needs whilst maintaining the current arena utilisation. You could have pretty much any working patterns in an open field near a motorway. Not so at Anfield with the residents in close proximity.
T'would be a tricky project.