Adding Day Lighting
Windows, once only viewed as a source of light, are now an opportunity for creative expression, as well as expansion of a room to outdoor surroundings. However, thoughtful use of delighting can restore windows to their original and finest role–illuminating life. Adding day lighting in the right amounts in the right places enhances a building’s aesthetics: the health of the occupants within and the overall mood and tone of a given room, so long as careful consideration is given to existing lighting needs as well as an evaluation of what roles daylight can be reasonably expected to fill.
Architect Sarah Susanka of Mulfinger, Susanka, Mahady & Partners comments on the opportunities daylight has to offer: “The window is an amazing thing, offering access to view, light and air. If we treat the act of placing a window in a wall with reverence, placement, composition and design of that window become issues”.
The brightness gained from both direct sun and skylight can bring daylight up to 15 ft. into a building, minimising the need for extra electrical light. Energy expenses are reduced (between 20-25% of all electricity produced is for lighting), as with the associated costs of fixture maintenance, air-conditioning and heat load. Indirect sunlight also reduces a bulb’s glare off internal surfaces while offering the optimum light source for viewing colours.
Building orientation and form are the primary means to maximising day lighting in the home. In the past, courtyards and atria were used to increase potential window space. With increasing demands on shrinking space, alternative means have been explored. During the energy crises of the 70’s, immense spans of glass were thought to make a home to expensive to heat and cool. Of course, the question of whether or not to use a large expanse of windows no longer applies. With Low E II and other types of glazing, as well as improved fenestration techniques, windows are now close to the energy efficiency of the walls that surround them.
The challenge now is how to offer enough light to improve liveability, where emphasis on the amount of light does not imply a loss in quality. Openings must be carefully sized and placed to avoid direct sunlight, which can be stressful to human eyes. Overhangs and setbacks, glass size, window coverings and reflective surfaces (both inside and out) can be used to control the type and amount of daylight admitted as well as to minimise glare. Susanka also offers the idea of placing a window close to a wall or ceiling to maximise light potential: ”Like a light fixture, the accompanying wall/ceiling surface offers a bounced-off light, making the surface float in a certain way”.
The benefits of well-designed day lighting are obvious. There is an irresistible attraction to a room that is filled with controlled sunlight. Whether used for task illumination or general ambience, the light in the room generates an immediate sense of well-being. The time spent there is more productive, pleasant and comfortable.