Although the company does operate data centres (including one near Heathrow and one in the docklands) I do not believe that this building in Whitechapel (see Google maps) is a data centre.
A recovery centre is an extremely highly spec’d backup office, that does have data storage on site, but this is to provide mirrored services from office that have suffered a disaster.
The building has many of the traits of a data centre, including reflective and dark windows, a secure loading bay, high levels of security and a building fabric similar to other data centres occupying former offices.
However, the building was subtly different in that it had a clearly marked entrance, with a reception and had numerous signs up to tell people that this is a Sunward AS building.
Visiting this building made me reconsider with the Sungard AS building in the Docklands is a data centre. In reflection probably not.