Spending a lot of time indoors, like most of us do, can disconnect us from nature. This is where daylighting comes to the rescue! Daylighting is a means of using natural light from the sun to illuminate a room and lets us keep electric lights off during the day, saving energy and money. You too can reconnect with nature inside your home with these eight guidelines:
1. In Cold Climates, use fewer windows on the building’s colder north side. Use double-pane, low-e windows with a U-factor of 0.35 or below (to keep heat inside your home) and a solar heat gain coefficient of 0.60 or higher (to allow more of the sun’s heat to enter your home.)
2. In temperate climates, use fewer windows on the west side. On south-facing windows, a simple overhang or awning will allow plenty of natural light in while keeping out the summer’s heat.
3. In hot and arid climates with intense sunlight, such as the Southwest, avoid west-facing windows if possible. Design windows to let in indirect daylight rather than direct beams of sunlight. Consider shading options such as deep eaves, verandas, awnings, exterior shutters, and deciduous trees and vines. Use low-e windows specifically designed for hot climates, with a solar heat gain coefficient of 0.40 or less (U-factor is less important than SHGC in hot regions).
4. In hot and humid climates such as the Southeast, position windows on two sides of a room to improve cross ventilation. A skylight that opens or a window placed high on a wall can provide a path for hot air to flow out of your house. Use exterior shading strategies to keep direct sun off all windows.
5. Bring in light from above with clerestories or skylights. Clerestories, which are windows placed high on the wall, often above the main roofline, allow daylight to penetrate deep into a room. If you’re installing skylights, consider models with translucent or prismatic glazing so the light from above is diffuse rather than uncomfortably bright.
Also consider tubular skylights, which are small circular skylights at the end of a reflective tube. They’re less expensive to install than regular skylights, and they make a good retrofit solution for existing homes.
6. Reduce glare by daylighting rooms from more than one side. For example, if large view windows dominate one side of a room, placing a row of small clerestory windows high on the opposite wall will help balance the light.
7. Take advantage of indirect daylight by using light-colored interior surfaces, including walls ceilings, floor coverings, and furnishings. Light surfaces reflect daylight, making the room brighter. Splayed window reveals and splayed skylight wells, especially if they’re painted white, also help spread daylight farther into a room. A window located close to a room’s corner will also help spread daylight by illuminating the wall that’s perpendicular to the window.
8. Think of windows as holes in your wall. Even with high-performance glazing, skylights and windows act a bit like holes in your walls–they’re much less effective at keeping heat in or out of your home than insulated walls are. If you’re remodeling or building a new home, be judicious with the size, number, and placement of windows and skylights.
Adapted from Good Green Homes, by Jennifer Roberts (Gibbs Smith Publisher, 2003). Copyright (c) 2003 by Jennifer Roberts. Reprinted by permission of Gibbs Smith Publishers.
Adapted from Good Green Homes, by Jennifer Roberts (Gibbs Smith Publisher, 2003).