The lower end estimate covers works planned directly by the council but could rise if other public sector clients in the region adopt its use.
The council said the framework, which is being split into five lots covering various sizes of traditional public construction projects and modular solutions, is expected to enlist up to 28 firms.
Lot one, which covers new build and refurbishment projects worth up to £2.5m we see a projected total spend of £15m-£50.
Two other lots for projects from £2.5m to £9m and bigger schemes will account for £50m to £220m of work.
A further £15m to £80m is forecast to be spent with modular construction specialists signed up by the council.
Interested firms have until 11 November to complete prequalification questionaires, available from the web portal.