Newcastle-based architect Faulkner Browns has won the contest to design the new £55m base for Rochdale Metropolitan Borough Council.
The building will be home to 2,000 council staff and extend to between 250,000 sq ft and 320,000 sq ft in gross floor area.
The development will also feature a new library and information centre, public customer services, training and conference facilities together with offices for the NHS. The current municipal offices, dubbed the Black Box locally, will be demolished together with an adjacent bus station.
A two-acre riverside site on Smith Street has been set aside for the new office. Construction is due to start next summer with the building opening in autumn 2012.
Separate contracts are yet to be awarded for the quantity surveyor, structural engineer, mechanical and electrical engineer and CDM co-ordinator.
Steve McIntyre, partner with Faulkner Browns, said: "We are absolutely delighted to be working with Rochdale Borough Council on this new building for customers and staff. It will provide a centralised location for public services and create a new and welcoming destination in Rochdale town centre. We are confident that the borough's residents will be proud of the building."
Faulkner Browns is arguably best known in the North West for designing the distinctive green Info Lab 21 buildings for Lancaster University viewable from the M6.