face east and west and sometimes those that face toward the nearer pole receive more sunlight than windows facing toward the equator. Types Passive daylighting is a system of both collecting sunlight using static, non-moving, and non-tracking systems (such as windows, sliding glass doors, most skylights, light tubes) and reflecting the collected daylight deeper inside with elements such as light shelves. Passive daylighting systems are different from active daylighting systems in that active systems track and/or follow the sun, and rely on mechanical mechanisms to do so. Windows Windows are the most common way to admit daylight into a space. Their vertical orientation means that they selectively admit sunlight and diffuse daylight at different times of the day and year. Therefore, windows on multiple orientations must usually be combined to produce the right mix of light for the building, depending on the climate and latitude. There are three ways to improve the amount of light available from a window: (a) placing the window close to a light colored wall, (b) slanting the sides of window openings so the inner opening is larger than the outer opening, or (c) using a large light colored window-sill to project light into the room. Besides permitting daylighting into the building, windows serve another function in daylighting practice, providing views out. To enhance the quality of the view seen from a window, three primary variables need to be ensure: view content (what can be seen in the view), view access (how of the window view can be seen), and view clarity (how clearly the view can be seen). View clarity is often influenced by the amount of shading provided by blinds or devices used to protect occupants from harsh daylight (e.g. glare) or for reasons of visual privacy. Environmental criteria can also be used to accurately predict preferences toward different window views. These criteria include: Location, time, weather, people, and nature. Research has shown among the five criteria, window views that contain nature have the height weighted importance. Different types and grades of glass and different window treatments can also affect the amount of light transmission through the windows. The type of glazing is an important issue, expressed by its VT coefficient (Visual Transmittance), also known as visual light transmittance (VLT). As the name suggests, this coefficient measures how much visible light is admitted by the window. A low VT (below 0.4) can reduce by