The Department for Education has confirmed in a letter to Darlington MP Jenny Chapman that the Mowden Hall site in the town will close.
The decision is part of a review of buildings used by the department. It is expected that staff will be relocated to new site in Darlington or Newcastle.
More top news
A group of protesters angry at threats of closure to children's centres in Newcastle have marched on a council-run surgery.
Breezy 24 hours, but not a bad Sunday in prospect
The NE sees the brightest of any sunny spells in the north of England on Saturday, but still an odd patch of light rain possible anywhere