Hull City Council has agreed to buy Bradbury House in Porter Street, Hull.
The building has been used as the headquarters of charity Age UK Hull since it was built in 2001. The charity will relocate to a more prominent city centre location in summer.
The building has been closed to the public since Tuesday 23 March due to the coronavirus pandemic.
The acquisition will allow the local authority to move staff from older properties in the city to the modern office space inside Bradbury House as part of its corporate property strategy.
It will include about 60 social services staff from the nearby Myton Centre in William Street, which is being acquired by Highways England as part of the A63 Castle Street major highways scheme.
Councillor Daren Hale, deputy leader of Hull City Council, said: “Bradbury House is an excellent purpose-built office building that will be an asset to the council.
“The acquisition is part of the council’s corporate property strategy, which includes the replacement of older or leased-in property with modern office space.
“As well rehousing staff at Myton Centre, Bradbury House will provide office space for teams currently occupying older or unsuitable property elsewhere in the city.
“It is really important to the council to have an office presence in the Thornton Estate, showing the council’s commitment to keeping a significant number of staff located there, and the demolished Myton Centre is to become a new greenspace for the residents on the estate.”
Staff from the charity will continue to deliver services from home until they move to new offices in late summer, according to chief executive Pam Davies.
She said: “We will be sad to leave Bradbury House, but this gives us a unique opportunity for the charity to flourish and develop over the years to come and adapt to the ever-changing needs of an older population.
“We have successfully continued to deliver key services to older people in the area from our homes and, with no reopening date in the foreseeable future, we plan to continue to deliver these services in this way until we move to our new offices during the late summer.”
Read more about the sale at the Age UK Hull website.