Building orientation can maximize opportunities for passive solar heating when needed, solar heat gain avoidance during cooling time, natural ventilation, and daylighting throughout the year. For example, southern exposure is the key physical orientation feature for passive solar energy in the northern hemisphere.

The basic considerations for optimizing the solar heating potential of a sunspace include the directional orientation and the angle of the glazing (glass or windows).

In general, a south-facing orientation within 30o east or west of true south will provide around 90% of the maximum static solar collection potential. The optimum directional orientation depends on site specific factors and on local landscape features such as trees, hills, or other buildings that may shade the sunspace during certain times of the day.

Rectangular buildings should be oriented with the long axis running east-west, so
the east and west walls receive less direct sun in the summer. In the winter, passive solar heat gain occurs on the south side of the building.

CONSIDER BUILDING ORIENTATION
Align the building along an east-west axis so windows face either north or south. In southern or hot climates, design large north windows to take in cool, diffuse north light. Minimize window height on the south side (strip windows work well), and shade the window from direct sunlight. When the sun is high in the south sky, a canopy or a tree makes an excellent sunshade.

In northern or cooler climates, place small windows on the north side and large windows on the south side to minimize heat loss and maximize solar gain during the winter. It is still important to shade south-facing windows during the warmer summer months to minimize solar gain during the cooling season.

Overhangs or other types of sunshades can be designed to admit the low winter sun while blocking the higher summer sun.  Deciduous trees are excellent for this purpose, admitting light in winter and providing dense shade in summer. A good rule of thumb for south-facing overhangs (assuming that the overhang is level with the head of the window): Make the overhang as deep as the window is high.

Minimize east- and especially west-facing windows; the sun is low in the morning and evening, creating a lot of glare and solar heat gain.