A clerestory (pronounced like "clear story"), are vertical walls with windows above the roof eave (edge) of a home. A clerestory can be a valuable passive solar strategy for homes in temperate and hot humid climates where there is an abundance of natural breezes and clear sunny days.
Windows in a clerestory are typically placed on the south facing portion of the clerestory to allow the sun's rays to heat up interior spaces in the north side of homes for passive solar heating. Operable clerestory windows facing prevailing breezes can also be a good source for natural ventilation during the summer, because the windows provide an escape for heat rising to the highest ceiling area, an effect also known as stack ventilation.
A clerestory can also add natural daylighting to the interior areas of a home that are away from perimeter windows. To be most effective, clerestory windows should be insulated, operable, and should be shaded from summer sun by roof overhangs.
