Designing for Natural Light Without Overheating
The instinct to bring in more natural light often defaults to bigger windows, which in a tropical climate can quietly work against you — every additional square meter of unshaded glass is an additional square meter of solar heat gain. The better lever is usually orientation and shading, not glass area alone.
North- and south-facing openings in most of Indonesia receive more even, lower-angle daylight through the year than east- and west-facing ones, which take a harsher, more direct hit from the rising and setting sun. Where east or west openings are unavoidable, deeper shading — overhangs, louvers, vertical fins — earns its cost quickly in reduced heat gain.
Glazing selection matters too. Low-E or solar-control glass can cut a meaningful share of solar heat transmission while keeping visible light levels close to clear glass, at a cost premium that's usually smaller than most clients expect once you compare it against a larger air conditioning unit and its running cost.
The goal isn't less light — it's light without direct sun exposure. A room lit primarily by diffuse daylight bounced off an exterior wall, a light shelf, or a shaded courtyard can feel brighter than one with a large unshaded window, without carrying the same cooling load.