A couple of years ago I built a 2 bed house which had to have a sprinkler system as it was down a long narrow driveway. Because sprinklers need a consistent and high volume flow the water main to the property was twice the size for just 5 rooms and you have very good to high water pressure.
So for something like a 20+ storey building such as this I don't think it is straightforward to retrofit, water is already going to be pumped but the sprinkler system would demand very high volumes.
Regarding building regs, we are inspected thoroughly, Fire and fire doors are a closely monitored part of the regs, they're fitted with closers but people tend to remove them or wedge them shortly after occupation.