Traditional
Traditional procurement requires a high level of experience from all the appointed consultants and the cost out turn is to a large extent dependant on the accuracy and completeness of the work carried out by the consultant team.
Until the cost from 3no. main contractors are returned and reviewed the actual construction price of the project is unknown and the work can only be tendered once planning and detailed designs are completed usually some 8-10 month into the project. This is a huge amount of time to wait to determine how much your building will cost!
In addition in traditional procurement there is usually no collaboration from the Main Contractor and the price after tender is based on a specific scope of work issued from the consultants. So if the documents are poor or the scope of work is undefined then the potential for change order is extreme hence why this process is adversarial and can lead to cost increase, delays on site and in some cases litigation.
The problem with this route is that the cost is unknown until a very late stage into the project and all the risk is with the consultant team with very little over site from a professional build point of view.