Common sense dictates keeping the old building in use until ready to begin construction.  Why was it torn down so early?  There are logical steps to implementing a project like this. Get council and public input on design characteristics; hire architect; finalize design; put it out to bid , with specific penalties for contractors lack of performance or cost overruns. If a contractor underbids (demoliton of old City Hall cost doubles), they usually eat it in real life.  Use the building of our Library as a model to how to do things right.