Lighting a room is about more than just the electrical lighting. There are many daylighting techniques that can lower the need for artificial lights in a building. These include smart lights connected to light sensors, which only come on to the required brightness. As well, sunlight can be used illuminate large portions of a room if it is distributed properly, so that overhead lights are completely unnecessary, or at least can be set lower, saving power and creating a nicer atmosphere.
Extensive use of skylights, light-shelves, and large windows make the Centre a bright and airy building. Without well-designed daylighting, the Centre could have been very dark inside -- it sits directly between two tall buildings (the building to the south, Goodwin Hall, is a seven-story building; Dupuis Hall, to the north-west, is five stories). The Centre was able to use an open structure, including an atrium, in combination with large windows and exceptionally large skylights, to maximize the availability of natural light throughout most of the building.
Designed to illuminate
On the north side of the building, the penthouse is sheeted in corrugated metal. Light reflects off the metal and through the skylights on the north side of the atrium, directing a large amount of light into the area. Skylights are also placed on each end of the atrium to let in east and west light.
The average lighting level for a classroom should be around 500 lux, and many areas in the IL Centre exceed that specification without artificial light, as a result of its daylighting designs. The initial plan was to angle the wall of the the mechanical penthouse to fully maximize the reflected light, but this proved too expensive (having an angled exterior wall requires extensive structural support) and was cut from the final building plans.
As well, glass was used where drywall would traditionally have been installed. The entire west-facing office wing is glassed in, instead of walled off, to allow light through to the atrium from the floor-to-ceiling windows on the west face. [Light shelves] are used in the office spaces to distribute light onto the ceiling and off desks, and to reduce [solar heat gain].
There is always a financial trade-off when implementing daylighting in a building. A skylight or a window is not as good at insulating as a roof or wall; there are often heat leaks around the frame. Every extra window means a break in the building envelope, and this can increase either heating loads or (due to solar heat gain) cooling loads. Window frame technology is always improving, however. If properly planned and placed, skylights and windows can brighten a dim room without costing much in heating bills; light shelves can spread light around and reduce the need for artificial lighting.