Seasonal Light Shift
This pattern is shaped by
Problem
When a building's relationship to sunlight is fixed — the same shading, the same glazing, the same orientation year-round — it is optimized for one season and wrong for the others. In Edmonton, the sun angle varies from 12° at winter solstice to 60° at summer solstice. A building that doesn't adapt to this 48-degree swing is fighting the climate for half the year.
Evidence and Discussion
The traditional tools for seasonal adaptation are elegant: deciduous trees that shade in summer and admit light in winter, roof overhangs sized to the latitude (blocking summer sun, admitting winter sun), operable exterior shutters, and adjustable louvers. The modern version adds motorized exterior blinds and electrochromic glazing, but the passive tools still work best.
Therefore
design every south-facing façade to respond to the seasonal shift in sun angle. Size roof overhangs to shade the glazing at summer solstice while admitting full sun at winter solstice (the overhang depth is a function of latitude and wall height). Plant deciduous trees on the south and west. Provide operable exterior shading for east and west glazing, where overhangs are less effective. The building should welcome winter sun and deflect summer sun — automatically, through geometry, without switches or sensors.