Cumbria County Council has issued a development brief to deliver 50,000 sq ft of new offices and refurbish existing council buildings as it seeks to rationalise its estate.
The council occupies around 30 separate buildings in and around Carlisle but most are out-dated. The council wants to bring this number down to between one and four within five years.
The revised offices will accommodate 1,000 staff overall. The brief said the development partner would also handle decommissioning and disposal of assets, property acquisition and the design and construction of new buildings.
The project will also seek to reduce the carbon footprint of the county's office space and the impact of staff and visitors travelling to the offices.
Developers have until the end of September to submit expressions of interest. The five highest scoring candidates will be invited to submit detailed bids.