Domestic life in the past was smelly, cold, dirty and uncomfortable, but we have much to learn from it. I spend much of my time working as a curator in Britain's historic royal palaces. But recently, for a television series, I've visited a lot of normal homes dating from the Norman period to the present day, and I've concluded that the houses of the past have a huge amount to teach us about the future. When the oil runs out, I think our houses will become much more like those of our low-tech, pre-industrial ancestors.

The first point is that the age of specialised rooms is over. Now, legislation governing the design of new houses contains echoes of the past: it insists that once again rooms should multi-task. The living room, for instance, must have space for a bed in case the occupant becomes incapacitated; medieval people, for instance, lived, ate and slept in one room – as I do, in my open-plan flat.

Next, architectural features from the past will start to reappear. The chimney disappeared in the 20th century, but it's coming back, as solid fuel-burning stoves make a return. In terms of fuel conservation the sun is becoming important again too: once upon a time people selected sites with good "air"; now well thought-out houses are situated to minimise solar gain in summer and maximise it in winter. Most future houses will need to face south, a challenge to conventional street layout.