One is that, since the late 1980s the average number of people living in each dwelling has fallen a little, so that the number of dwellings has increased a bit more quickly than the population.
Another is that, over time, the average quality of our dwellings has improved and the average size of the dwellings has increased; for example, since the late 1980s, the average floorspace of newly constructed houses has risen by around 45 per cent (Graph 6).