The behaviour of building occupants can have much influence on energy consumption. In developing countries, using energy is often still a symbol of richness. In Austria, for example, we still flush the toilettes with perfect drinking water (which could be also filled in bottles).
Are people aware of that? The use of greywater and stormwater for flushing is still regarded as "too expensive"! At least the Vienna Department for Social Housing expects planers to use water saving two-button flushes. Smart flushing systems use so only 6 litre maximum instead of 14 (!).
It's just a simple trick to save some water.