Southway Housing Trust is relocating its headquarters to Aspen House in South Manchester.
Southway will occupy the entire 18,942 sq ft building, set in 4.5 acres of gardens in Meadow Court, Wilmslow Road, Didsbury, at a rent of £15/sq ft to owners Norwich Union. The deal includes 89 car park spaces.
Rob Yates of DTZ, letting agent for Norwich Union, said: "This is quite a significant deal for south Manchester given the effects of the credit crunch."
Southway, which controls a large amount of housing stock in the area and has just taken on 5,900 properties from Manchester City Council, will be moving from its offices in Copson Street, Withington.
Lambert Smith Hampton acted on behalf of Southway.