For the design consideration, a few factors have to be concerned. For example, Environmental factors, Fenestraction, Obstructions, Room Dimensions, Glare, Shadow intensity and direction of incident light and Permanent supplementary artificial lighting of the interior.

For the environmental factors, daylight design is closely related to a number of environmental factors because the use of glass windows to let in light also allows the penetration of solar heat and noise and increase the rate of heat gain or loss of the building fabric. Therefore, daylight design can never be considered alone. Fortunately by the proper choice of window orientation and suitable sun shading device or constructions, the solar heat gain can be greatly reduced. The use of double glazed window units is able to cope with the noise problem and reduce significantly the heat gain or loss through the window. The remaining problem would be the proper design of windows or rooflights to provide a visually comfortable and efficient environment for the type of tasks and activities to the performed.

For the fenestration, the lighting conditions in a room depend primarily on the fenestration. The illumination near the window decreases as the height of the window above the floor is increased. However, the illumination increases away from the window, giving greater uniformity to the lighting.

The following points should be considered in the design of fenestration:

the window head should be as high as possible, say at least 2m above floor
     level, to enable one can see out when standing.

the window sill should not be higher than 1m from floor level to enable one
     can see out when sitting.

the window surface area should be evenly distributed over the outside wall
     and the window heights and widths should not be too small in relating to the
     window wall because this reduces the uniformity of lighting and produces
     undesirable shadows.

better lighting can be achieved with windows on opposite walls since the
     illumination produced by the individual windows are superimposed. The
     region with the minimum daylight factor is then displace towars the centre
     of the room. The usable depth of the room thus increase.