The house that faces south

In the northern hemisphere, a window facing south receives sun for most of the day. A window facing north receives almost none. This single fact has shaped how houses are built across the world, long before anyone used the word design.

Traditional houses in cool climates put the main living rooms on the south side and the storage, stairs and bathrooms on the north. The arrangement is free: it costs nothing to decide which side a room goes on, and it changes how much heating the building needs for its entire life.

The detail that makes it work is the angle of the sun through the year. In summer the sun is high, so a modest overhang above a south window shades it at midday. In winter the sun is low and comes in underneath the same overhang, warming the room exactly when warmth is wanted. One piece of unmoving roof does both jobs because the sun moves and the roof does not.

In hot climates the logic reverses, and so do the buildings. Narrow streets for shade, small windows on the sunny side, thick walls that absorb heat slowly, and courtyards that pull cool air through at night.

None of this requires technology. It requires deciding things in the right order, and the orientation of a building is the cheapest decision available and the hardest to change afterwards.