Which daylighting approach supports daylighting while minimizing overheating risk?

• A. Direct sunlight through large glass with no shading.
• B. Rely on artificial lighting alone.
• C. Provide diffused daylight with shading, light shelves, vertical louvers, and reflective surfaces; avoid direct sun through glazing; clerestories with shading.
• D. Dark, non-reflective interior finishes.

Answer: (C)

The idea being tested is how to use daylight effectively while keeping overheating risk low. The best approach brings in daylight as diffused, evenly distributed light and uses shading and reflective surfaces to control heat and glare. Diffuse daylight reduces hot spots and glare compared to direct sun, and shading devices—such as light shelves, vertical louvers, and clerestory shading—limit direct solar gain while still allowing ample daylight penetration. Reflective interior finishes help distribute the light deeper into the space, improving daylight effectiveness without increasing heat load. Avoiding direct sun through glazing is key to minimizing overheating because direct sunlight can dramatically raise cooling needs and create uncomfortable glare. In contrast, relying on artificial lighting misses the energy-saving benefits of daylight, and very dark, non-reflective interiors waste available daylight by absorbing or blocking it rather than distributing it.