Forum: Cool coatings for HDB blocks cut surface heat absorption and emissions

We thank Forum writers Erik Velasco (Evaluate effect of heat-reflective paint, so it doesn’t cause issues, Feb 7) and Joseph Goh (Using cool paint in urban environments has positive net impact, Feb 13) for their feedback.

To mitigate the effects of urban heat, HDB has been studying the use of cool coatings under our HDB Green Towns Programme. Cool coatings reflect visible and near-infrared radiation, reducing surface heat absorption and emissions, thereby lowering ambient temperatures.

As Mr Goh pointed out, while the solar radiation reflected by cool coatings may raise localised temperatures slightly, this effect is minimal, compared with the overall reduction in heat absorption by buildings and urban surfaces.

Findings from our two-year pilot in Tampines have shown that cool coatings reduced ambient temperatures by up to 2 deg C. With a cooler environment, residents living in blocks painted with cool coatings used less air-conditioning to cool their flats, leading to reduced electricity consumption. This resulted in lower waste heat emissions from buildings, which helps to offset any localised warming.

On Mr Velasco’s concern about chemical discharge from cool coatings, we would like to clarify that the cool coatings used in HDB estates are water-based coatings with low volatile organic compounds, similar to conventional paints, and comply with Singapore’s safety and environmental standards.

In tandem with the cool coatings initiative, HDB adopts other sustainable design strategies to create a more liveable and quality living environment for our residents. This includes designing and orientating our buildings to reduce solar heat gain from solar radiation and optimise wind flow, as well as intensifying greenery in our estates in the form of urban farms, community allotment gardens or roof-top gardens.

Before implementing our programmes such as the cool coatings initiative, HDB consults experts in the related fields and reviews the results of any trials or pilots comprehensively, to ensure safety and benefits to our residents. 

We will continue to review the progress and effectiveness of our initiatives to keep our estates liveable and resilient in the face of climate change.

Tan Sze Tiong

Chief Sustainability Officer
Housing & Development Board