On the other side of the table, there are great benefits for a park district to become its own general contractor, the biggest of which is cost containment during the early stages of the project development. By performing preliminary floor plan designs and determining ballpark costs of construction, park districts can have an idea if a project is feasible in order to avoid the embarrassment of announcing a project only to find out later that it is unaffordable. Another advantage is that it can be safer to serve as your own project manager and general contractor than to put yourself totally in the hands of your architect and the turnkey general. Just ask the Westmont Library board about the effects of a general contractor going bankrupt during a major construction project. It's a horror story which is not as rare as might seem.
General contractors walk or threaten to walk all the time.
Many of the low bidders make mistakes in bidding and have no alternatives but to issue threats if change orders or outright changes in their bids are not permitted. This is because most generals use the same subcontractors with which they are familiar from job to job. That is why, other than errors and profit motives, there is so much difference in the bid prices between generals. One generals bundle of subs differs from another, sometimes substantially. But since a park district serving as its own general gets the lowest bidders in each case, its bundle of bidders should always be lower overall.