Which of the following is a shading strategy to minimize solar heat gain in tropical buildings?

• A. Timber floors
• B. Overhangs and shading devices
• C. Single glazing
• D. Concrete block walls

Answer: (B)

Shading strategies that intercept solar radiation before it enters the building are essential for minimizing solar heat gain in tropical buildings. When the sun is high and intense, direct sunlight can overwhelm indoor spaces and raise cooling needs quickly. Overhangs and other shading devices block or deflect this direct solar radiation on windows and walls, while still letting in daylight. This reduces radiant heat entering the interior, lowers indoor temperatures, and cuts the cooling load without sacrificing natural light.

In practice, a well-designed overhang swings into action during the hottest parts of the day, especially when the sun angle is steep, so hot sun is kept out while cooler morning or late-afternoon light can still enter. Other shading devices—louvers, screens, fins, or vegetation—work similarly by providing a barrier that reduces heat gain at the façade.

Materials or configurations that don’t specifically block sun—like timber floors or concrete block walls—don’t inherently reduce incoming solar heat. Single glazing allows more heat to transfer indoors, increasing cooling requirements, and unless paired with other shading or insulation, it tends to raise heat gain. By contrast, shading is a direct, proactive method to keep interiors cooler in tropical climates.