All construction work is based upon contract, whether it be oral or in writing, but the first question to ask is whether there is in fact a contract at all. A building contract should define the relationship between the parties so that each knows what is going to be built, how long it should take and how much it is going to cost. In simple terms a contract is an exchange of promises, the breach of which results in a remedy at law. Thus, the essence of a building contract, like any other contract, is agreement. There has to be a point at which the parties are ad idem, i.e. of the same mind, as regards the terms of the contract they wish to agree and generally the contract will be formed when the parties reach that point.