The BBC's proposed move of five departments from London to the north-west of England has been given the go-ahead.
The centrepiece will be a piazza twice the size of Trafalgar Square
Five Live and BBC Sport are among those being relocated to the mediacity:uk development at Salford Quays.
The BBC Trust has approved the terms of the deal. Work on the site will begin within days and be completed by 2011.
BBC director general Mark Thompson said he was "delighted" the move was now "firmly on the road to reality".
The BBC Trust reached agreement with the developer Peel Holdings over the detailed terms under which it will occupy buildings in the mediacity:uk development.
Mr Thompson, added: "I'm delighted that the BBC's vision for its expanded presence in the North of England is now firmly on the road to reality.
"I'm excited by the plans and believe they have a key part to play in the BBC's future.
"The modern, multimedia broadcast and production centre in Salford will shift the BBC's centre of gravity away from London, bringing a range of creative benefits to us and, I hope, helping us to better reflect and represent the whole of the UK.
"I'm glad that the BBC Trust agreed that this project represents value for money for licence fee payers and that we are now able to proceed."
The BBC will move five London-based departments, including two television channels and two radio networks, to Salford Quays. They are:
BBC Children's (including CBBC and CBeebies television and radio)
BBC Children's Learning
Parts of BBC Future Media & Technology (including BBC Research & Development)
BBC Radio Five Live (including Five Live Sports Extra)
The move will see approximately 1,500 London-based posts will relocating to Salford Quays in 2011.
Around 800 staff currently based at the BBC in Manchester will also move to the new site.
Caroline Thomson, chief operating officer of the BBC, said: "I'm delighted that we have now finalised the terms for the BBC's presence at the mediacity:uk development.
"This is a really exciting project for us all and I look forward to working with colleagues in Peel Holdings and the development consortium to turn the vision into a reality."