[extract] The issue which we wish to examine in this article concerns contractual rights related to personal preferences. By this, we mean a contract which stipulates a preference, but to which no commercial value can be attached. Suppose, for example, I state in my requirements for a contract, that bricks of a certain type are to be used in a building. After the building has been completed, it is realised that bricks of another type have been used. Now it may well be that the bricks which have been used are just as robust as the ones I stipulated for, and indeed, many may think them to be more attractive. If I compare the value of the building as built, with the building as specified in the statement of requirements, there may be no difference. So I cannot argue that I have been given something of lesser commercial value. Yet if I ask the builder to take the building down and rebuild it using the bricks as specified (at the builder’s expense) I might well be met with the argument that the extra cost is out of proportion to the benefit which I could possibly gain.