Rack space is still scarce in London's data centres, but indications are that an end to the capacity crunch is in sight. Despite growing deployment of blade servers and virtualisation, the demands on UK data centres continue to escalate. New data centre build-outs in the Greater London area have been further inhibited by legislative requirements, designed to ensure that new data centres meet specific environmental requirements before planning applications are approved. The migration of power-hungry applications to the outlying areas will then free up space in central London data centres and erode the business case for building more facilities in London. This approach would mean that significant amounts of floor space would be freed up.