Daylighting (architecture)

Lore & Background

Daylighting strategies vary with site locations and climates, as each climate has different composition of direct and diffuse daylight and different cloud coverage. At latitudes north of the Tropic of Cancer and south of the Tropic of Capricorn, there is no direct sunlight on the polar-side wall of a building between the autumnal equinox and the vernal equinox. Traditionally, houses were designed with minimal windows on the polar side, but more and larger windows on the equatorial side.

Reader's Guide

Daylighting is significant for reducing energy use through decreased reliance on artificial lighting and passive solar heating. It encompasses passive systems like windows, skylights, and light shelves, as well as active systems that track the sun. Windows are the most common daylighting element, with their effectiveness improved by placement near light-colored walls, slanted openings, or large light-colored sills. Clerestory windows, sawtooth roofs, skylights, laylights, and atria are other key elements. The human eye's non-linear response to light means that even distribution of the same amount of light makes a room appear brighter. The proportion of direct to diffuse light impacts daylight quality, and strategies must adapt to local climate and latitude.

Did You Know?

• Artificial lighting energy use can be reduced by automatically dimming or switching off electric lights in response to daylight, a process known as daylight harvesting.
• At latitudes north of the Tropic of Cancer and south of the Tropic of Capricorn, there is no direct sunlight on the polar-side wall of a building between the autumnal equinox and the vernal equinox.
• Views that provide building inhabitants with content of nature far outweigh the other four Environmental Information Criteria for window view quality.
• A laylight differs from a skylight in that a skylight functions as a roof window or aperture, while a laylight is flush with the ceiling of an interior space.