Pattern 2: Window Area (Window Spacing)

10% Glazing Area

Vertical windows (3’-0” X 7’-0”) at 10 percent of the wall area provide no area that meets or exceeds commonly accepted minimum daylight illumination criteria. The contrast between interior surface and views to the exterior create a high likelihood of glare and visual discomfort. All interior surfaces are dark in relation to the glazing.

Pattern 2: Window Area (Window Spacing)

20% Glazing Area

Pattern 2: Window Area

Vertical windows (3’-0” X 7’-0”) windows at 20 percent of the wall area provide daylight illumination that meets or exceeds commonly accepted minimum daylight illumination criteria at approximately 10 percent of the adjacent 26’-0” section. A high level of contrast exists between the interior surfaces and the glazing. Few of the interior surfaces receive sufficient illumination to balance the contrast of the glazing, this is especially problematic at the interior surfaces surrounding the glazing, creating a likelihood of visual discomfort.

Pattern 2: Window Area (Window Spacing)

30% Glazing Area

Pattern 2: Window Area

Vertical windows comprising 30 percent of the wall area provide daylight illumination that meets or exceeds commonly accepted minimum daylight illumination criteria at approximately 40 percent of the adjacent 26’-0” section. Excessive contrast remains between the interior surfaces and the glazing. The interior surfaces are beginning to receive some illumination to balance the contrast with the windows. This is most noticeable on the lower portion of the “back” wall (at left).

Pattern 2: Window Area (Window Spacing)

40% Glazing Area

Pattern 2: Window Area

Vertical windows at 40 percent of the wall area provide daylight illumination that meets or exceeds commonly accepted minimum daylight illumination criteria at approximately 50 percent of the adjacent 26’-0” section. Some contrast remains between the interior surfaces and the glazing, though the “back” wall (at left) shows a substantial increase in surface brightness to balance the luminosity across the section.

Pattern 2: Window Area (Window Spacing)

50% Glazing Area

Pattern 2: Window Area

Vertical windows comprising 50 percent of the wall area provide daylight illumination that meets or exceeds commonly accepted minimum daylight illumination criteria at approximately 80 percent of the adjacent 26’-0” section. Some contrast remains between the interior surfaces and the glazing, though the “back” wall (at left) shows a substantial increase in surface brightness to balance the luminosity across the section. Note that at this window to wall ratio, the vertical windows are geometrically equivalent to the horizontal band when bounded by a 2’-6” sill and a 9’-6” head height.