In the summer of 1967, the environmental systems of the International Monetary Fund Building in Washington, D. C., went on line under direct control of a digital computer. The track record established for the past five years is of importance to everyone in our industry, in view of the opportunities and challenges that will become paramount in this decade of fossil fuel shortages. The results obtained at the IMF building and others confirm that computers are the hinge on which the door to completely automated buildings will swing.