Historically, the architectural form of buildings, placement of windows, and location of rooms were guided by the availability of daylight as the primary source of illumination. Daylight was the only source of abundant light for buildings, provided through deep windows and thick walls and perhaps replaced (although inadequately) in theevening by the flicker of a candle flame or an oil lamp. Building form changed dramatically with the development of fluorescent lighting technologies, allowing interiors to be uniformly lit by electric lighting systems and to function at cooler temperatures (as opposed to the higher temperatures produced by heat-intensive incandescent lamps). Designing with daylight can improve energy efficiency by minimizing the use of electricity for lighting as well as reducing associated heating and cooling loads. Day lighting is a critical design factor to those concerned about global warming, carbon emissions, and sustainable design—in addition to visual comfort. Research has found daylight to be an important factor influencing human behavior, health, and productivity. Windows admitting daylight provide occupants with a view and a temporal connection with the outdoors. Daylight renders the environment in a vivid range of experiences and delight. It is important for basic visual requirements to view tasks and to perceive space. How daylight is delivered is in the hands of the designer at the beginning stages of design. The option of ignoring daylight in our high-energy-cost and rapidly-diminishing-natural-resources world is no longer available. This chapter describes daylight strategies to increase occupant satisfaction, control glare, provide appropriate vertical and horizontal illumination, and address the potential for energy savings to enable the designer to create a proper visual environment.