Solar glazing admits direct sunlight into a space for passive heating in winter.

Solar glazing (facing the equator) is sized to admit enough sunlight on an average sunny winter day to heat a space over the full 24-hour period.

Size solar glazing as a percentage of the floor area to be heated:

Cold Climates*

  • 16% at 28º – 40º latitude
  • 20% at 44º – 56º latitude

Temperate Climates**

  • 10% at 28º – 40º latitude
  • 13% at 44º – 56º latitude

Orient solar glazing within 15º of true south in the Northern Hemisphere, or true north in the Southern Hemisphere, and no more that 25º from either orientation. Store a portion of the heat gained during the day for release at night by locating thermal mass in the space. In very cold climates, incorporate moveable insulation over the glazing at night.

*Cold = Winter temp. -6.7ºC to -1.1ºC (20ºF to 30º F); **Temperate = Winter temp. 2.2ºC to 7.2ºC (35ºF to 45º F).  Recommendations are for residential and skin-load dominated commercial and institutional buildings.  

For detailed information and calculations, see the 2030 In-Depth Information Page under Tools + Resources.