As Colombo heats up, passive cooling offers a low-energy solution — but at a cost

In Colombo, residents like Fathima Rinoza struggle with heat in cramped apartment blocks where crowded buildings block airflow and open windows invite dust, odor, and theft. Engineers and architects point to passive-cooling strategies, cross ventilation, building orientation, shaded courtyards, and materials like clay brick and interlocking tiles, as low-energy alternatives to fans and air conditioners that now account for a large share of residential energy use.

Researchers note passive cooling depends on factors like wind and orientation that are often outside a resident's control, and that comfort temperatures achievable through natural ventilation are higher than those produced by air conditioning. For many urban dwellers, the bigger obstacle isn't engineering but money: Rinoza has had to permanently seal one window and bar the rest after a break-in, trading airflow for security she can actually afford.

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