★ Some skylights have expensive glazing reduces summer solar heat gain, while still allowing some visible light transmission. However, if visible light can pass through it, so can some radiant heat gain ►They are both electromagnetic radiation waves (see pictures below)

★ Operable shading and insulation devices

★ A design with too much equator-facing glass can result in excessive winter, spring, or fall day heating, uncomfortably bright living spaces at certain times of the year, and excessive heat transfer on winter nights and summer days.

★ Although the sun is at the same altitude 6-weeks before and after the solstice, the heating and cooling requirements before and after the solstice are significantly different. Heat storage on the Earth's surface causes "thermal lag." Variable cloud cover influences solar gain potential. This means that latitude-specific fixed window overhangs, while important, are not a complete seasonal solar gain control solution.

★ Passive solar design or climatic design

In passive solar building design, windows, walls, and floors are made to collect, store, and distribute solar energy in the form of heat in the winter and reject solar heat in the summer. Unlike active solar heating systems, it doesn't involve the use of mechanical and electrical devices.

★ The key to designing a passive solar building is to best take advantage of the local climate. Elements to be considered include Window placement and glazing type

★ Thermal insulation, thermal mass, and shading.

★ Exterior colors reflecting - absorbing

Materials and colors can be chosen to reflect or absorb solar thermal energy. Using information on a Color for electromagnetic radiation to determine its thermal radiation properties of reflection or absorption can assist the choices

★ Passive solar design techniques can be applied most easily to new buildings, but existing buildings can be adapted or "retrofitted"