I don't dig that

""The biggest investment in this came from BT, which had to dig up 11km of road to get the fibre in."

Couldn't most of that distance have been covered by other means, eg microwave?

There's far too much unnecessary and uncoordinated road digging already -- and I wouldn't mind betting that the claimed carbon saving of the centre is significantly dwarfed by the petrol wasted due to the traffic jams and/or the need to take longer alternative routes while the digging took place.

If you want to save energy, start by severely restricting most roadworks.