Direct sunlight on windows will consequently cause buildings to overheat. The basis of solar shading principles is to allow diffuse daylight into buildings while shading from direct sunlight.
The equator runs across East Africa, through Kenya and southern Uganda. Along the equator the sun at midday is directly overhead throughout the year. This means that in East Africa roofs receive far more solar radiation than walls.
Glazing acts as a heat trap by permitting short wave solar radiation to enter but not allowing longer wave thermal radiation to escape.