What is the rationale for a building scheme?

The leading case dealing with the rationale for a building scheme is Russo v. Field, 1973 CanLII 10 (SCC), [1973] S.C.R. 466. The following extract is apt: The mercantile device of a small shopping centre in a residential suburban area can only be successful and is planned on the basis that the various shops therein must not be competitive. Since the shopping centre is a local one and not a regional shopping centre, the prospective purchasers at the various shops which it is planned to attract are residents in the neighbourhood. They are, of necessity, limited in number and therefore the business which they bring to the shopping centre is limited in extent. The prospective purchaser attracted to shop A in the plaza may well turn from shop A to shop B to purchase some other kind of his or her needed goods or service but if the limited number of prospective purchasers are faced in the same small shopping centre with several prospective suppliers of the same kind of goods or service then there may not be enough business to support several suppliers. They will suffer and the operator of the shopping plaza will suffer. (at page 12, S.C.J. No. 58)