Give every room in which people spend time daylight from at least two sides; plan the building in narrow wings so that this is possible.
Turn the long side to the south
Lay out the rows east–west so that the long, glazed face of every house turns to the south (in the northern hemisphere), taking the low winter sun and shading easily from the high summer sun.
Olgyay calculated, climate by climate, the orientation that balances useful winter gain against summer overheating; in temperate latitudes it lies close to due south. A south-facing wall receives much more sun in winter than in summer, the reverse of an east or west wall, which is why the solar settlements of Freiburg and BedZED are built in east–west rows.
Related rules
Shape the space between buildings as carefully as the rooms: make outdoor spaces partly enclosed and convex, like outdoor rooms, rather than leftover gaps around freestanding objects.
On an equator-facing window, make the overhang deep enough to shade the whole window from the high noon sun of summer, and no deeper, so that the low winter sun passes beneath it into the room.
noon sun altitude = 90° − latitude ± 23.44° · overhang D = window height ⁄ tan(summer altitude)
Place heavy materials (concrete, stone, brick, earth) where the winter sun falls on them inside the insulated envelope, so that they absorb heat by day and give it back at night.
Make neighbourhoods compact, pedestrian-friendly and mixed in use, with a clear centre and edge, so that daily needs lie within a short walk: about a quarter of a mile, five minutes, from centre to edge.
centre to edge ≈ ¼ mile ≈ 400 m ≈ 5 minutes on foot
Set the gap between rows so that the shadow of each row at noon on the chosen winter day falls short of the glazed face of the row behind it.
gap = H ÷ tan α, with α = 90° − latitude − 23.4° at the winter solstice (at 48° N, α ≈ 18.6°: gap ≈ 3 H)
Cite this page Chris Paton, “Turn the long side to the south”, The Textbook of Architecture, https://textbookofarchitecture.com/rule/solar-south-orientation. Text, drawings and models licensed under CC BY-NC 4.0.