An Ipswich office block, which has stood empty since it was built in 2000, has its first occupants.
Suffolk Police and Suffolk County Council have moved some of their services to Landmark House, Whitehouse.
Ipswich police station is moving there and the existing town centre building will be sold, while the council is selling five of its vacated offices.
Both organisations estimate the move will save jointly save them £1m a year over the 30-year life of the building.
The four-storey office block was built by Agilent Technologies next to the A14, but the company never moved in.
Landmark House will be home to 850 police and council staff.
The police and council said they bought it in 2010, for just under a third of its £12m asking price.
The council has moved its trading standards, community safety, adult community services south team and some of its children and young people's services workers to Landmark House.
It is now looking to sell its Ipswich offices at St Edmund's House, Belstead House, Tower Street and Whitehouse and its Kerrison training centre off the A140.
The front desk will remain open at the town centre police station, until a new reception is created at Landmark House.
The coroner's office is also moving to the new building.