All of the building’s windows are either reflective or blacked out, there are numerous (but small) cooling units on the building and it is topped by an array of satellite receivers that are often used as a back up connection.
As I couldn’t decide if this building was a data centre I asked the security guard, who told me the building is empty. It is set to be demolished to be replaced by a 70-storey residential building.
At one point the building was occupied by BT so possibly this is was a communications building, but not a data centre?
As it is now unoccupied and there is very little information online I doubt I will ever know.