The contract has been compared with BT's Project Jaguar, a maintenance and facilities management package.
Each bidder for the building in Newbury, Berkshire, has been asked to suggest the most progressive way to procure and construct it.
The contract is to be awarded next month to a single bidder. The shortlisted firms are: Amec, Balfour Beatty, Bovis Lend Lease, HBG, Interior Services Group and Mace.
Clive Birch, director of Buro 4, the scheme's project manager, said: "We've asked all the shortlisted bidders how they would improve efficiency, eliminate waste and increase productivity along the lines put forward by Sir John Egan.
"The whole idea is to ensure that we deliver best value for the client and make contractors more efficient. We want to move away from the traditional type of contract," he said.
He added: "The successful bidder will have to agree to a series of key performance indicators for all aspects of the work. The project itself will be split into three packages but will be awarded to a single construction supplier.
"We're looking for price certainty, but bidders are not being asked to price the job. We have given them our cost plan to work within, but they can cost it in stages."
One of the bidders said: "It's the shape of things to come. Big clients such as Vodafone and BT want Egan-style efficiencies. They want to be more involved and want to form good partnership arrangements with suppliers."
Birch said the contract would also include proper risk sharing between client and contractor.
He said: "We believe that this project's approach to risk sharing is unique. If the contractor brings in a package below the tendered price, we will split the money saved 50-50. If the work comes in over the tendered price, we will split the additional cost 50-50 as well."
The shortlisted bidders were chosen on the basis of information they provided on their approach to partnering and the principles outlined in the Egan report, such as best practice and innovation.
Another of the bidders said: "It does involve a lot of front-end work, but this is a big, interesting job for a very good client."
It is due to go on site in April once planning approval is granted. Architect is Fletcher Priest.