Forum: Using cool paint in urban environments has positive net impact

I refer to comments by Mr Erik Velasco on the broader environmental impact of cool paint (

Evaluate effect of heat-reflective paint, so it doesn’t cause issues

, Feb 7).

Studies conducted by the Nanyang Technological University, including trials in a JTC industrial area (2018 to 2019) and on HDB flats (2020, 2024) have shown that heat-reflective paint, also called cool paint, can lower ambient temperatures by up to 2 deg C.

While such paint effectively reduces indoor temperatures and mitigates the urban heat island (UHI) effect, questions have been raised about its broader atmospheric impact. However, research indicates that the benefits far outweigh potential drawbacks.

It is true that as cool paint reflects solar radiation, it may slightly raise localised temperatures near the ground, adjacent buildings and greenery. However, this effect is minimal compared with the overall reduction in heat absorption by buildings and urban surfaces. 

Moreover, in a dense cityscape like Singapore, less reliance on air-conditioning means lower waste heat emissions from buildings, helping offset any localised warming. 

On a larger scale, against the Earth’s vast atmosphere, the fraction of heat reflected from urban surfaces is negligible compared with the total solar energy absorbed and re-emitted globally. 

Several implementation strategies can be employed to maximise the effectiveness and minimise the unintended consequences of using cool paint. These strategies include using eco-friendly, durable formulations with low volatile organic compound emissions, complementing cool paint with urban greenery and shading for optimal thermal comfort, and continuously monitoring localised impacts to refine deployment strategies.

Overall, the net impact of cool paint in urban environments like Singapore is positive. By lowering energy consumption and reducing greenhouse gas emissions, it can play a key role in climate mitigation efforts. 

While reflected heat is a factor, its effects are minor compared with the significant benefits in reducing energy use, cutting emissions and mitigating the UHI effect.

Joseph Goh
Vice-President
The Institution of Engineers, Singapore