Stand-alone single-family dwellings are the dominant housing type in several countries. The floor-area of the average stand-alone dwelling has been increasing faster than the floor-area of the average apartment/flat/row-house in England, Australia, Canada, the USA and New Zealand. Standalone dwellings have a greater external heat transfer area than multiple family dwellings, for the same floor-area. Larger dwellings require more energy to heat than smaller dwellings insulated to the same level. Although insulation requirements have been increasing, the heating required to maintain newer larger stand-alone dwellings to a constant temperature can be similar to that required to heat older smaller stand-alone dwellings. Building regulations should be future proofed by considering trends in dwelling size.