This study investigates the energy and cost performance of thirtyrecent buildings in Melbourne, Australia. Commonly, buildingdesign decisions are based on issues pertaining to constructioncost, and consideration of energy performance is made onlywithin the context of the initial project budget. Even where energyis elevated to more importance, operating energy is seen asthe focus and embodied energy is nearly always ignored. Forthe fi rst time, a large sample of buildings has been assembledand analysed to improve the understanding of both energy andcost performance over their full life cycle. The aim of this paperis to determine the relationship between energy and cost usingregression analysis for a range of building functional types.The conclusion is that energy and cost are strongly correlated,independent of building area, and equations are presented forfuture modelling of energy using cost as the independent variable.