Perforated Masonry Walls are used for shading and daylighting in buildings. Researchers studied different brick patterns to see how they affect light transmission. They found that the visual transmittance of these walls decreases as the angle of sunlight increases, with the most reduction happening at angles over 45°. Testing in a room with a South-facing window showed a 15% decrease in indoor light levels when using these walls as shading. The size of the holes in the walls doesn't predict how well they block sunlight.