Network Rail has received planning permission to build its new eco-friendly national centre in Central Milton Keynes for 3,000 employees.
The 122km² building will be built on the site of a former hockey stadium. Councillors voted to approve plans at a town hall meeting last week.
Construction is expected to start in August, with the building scheduled to open in 2012.
The design for the new building includes a host of eco-friendly features including extensive living roofs which will encourage diverse habitats for flora and fauna in the centre of the city and a rainwater harvesting system which will be used to flush toilets and irrigate landscaping.
Milton Keynes Partnership, the current owner of the site, has already made progress in clearing the land to get it ready for development.