A sunspace located or integrated along the solar façade of a building heats itself and adjacent spaces in winter.

A sunspace is heated by direct sunlight with heat transferred to adjacent spaces through a common mass wall.

Size the sunspace glazing area (facing the equator) as a percentage of the floor area of adjacent space to be heated:

Cold Climates*

  • 30% at 28º – 40º latitude
  • 40% at 44º – 56º latitude

Temperate Climates**

  • 20% at 28º – 40º latitude
  • 30% at 44º – 56º latitude

Make the thickness of the common mass wall

  • 20 – 30 cm (8 – 12 in) for adobe
  • 25 – 36 cm (10 – 14 in) for brick
  • 30 – 46 cm (12 – 18 in) for concrete

Use wall openings, windows, or doors to transfer additional heat between spaces.

*Cold = Winter temp. -6.7ºC to -1.1ºC (20ºF to 30º F); **Temperate = Winter temp. 2.2ºC to 7.2ºC (35ºF to 45º F).