The basic planning act, law no. 1150 of 1942, allocates the commune a major role in planning, and this role was maintained by the postwar constitution. The reconstruction plans followed closely the principles of the building plans established in 1865, in the early years of a united Italy, but the hygiene and design criteria of that period were completely ignored. Communes have more formal than substantial powers, and are governed by an elected council. There are 8,096 communes in Italy, varying in population from a few dozen to several million. A group of communes may prepare an economic plan or scheme for the development of productive sectors of the economy, in association with the land-use plan. Urban planning standards were adopted for control of buildings as a compulsory and standardised part of communal planning control under Bridge law. Urban planning has concentrated instead on building development, especially in the context of the growth of existing centres.