Study of Indoor Heat in Vulnerable Flat Types and Estates, and Targeted Grants or Retrofits for Affected Households

Mr Saktiandi Supaat asked the Minister for National Development (a) whether HDB has studied indoor temperatures in top-floor, west-facing and older public-housing flats during periods of extreme heat; (b) which flat types and estates are most vulnerable to excessive indoor heat; and (c) whether additional grants or retrofit programmes for heat-reflective coatings, shading, ventilation and energy-efficient cooling will be considered for affected households.

The Housing and Development Board (HDB) has observed that top-floor units and units located at the ends of the blocks are generally more prone to indoor heat. HDB incorporates design features to reduce heat. These include orientating blocks in the north-south direction where possible, carrying out environmental simulations to achieve natural cross ventilation and wind flow, installing a secondary roof above the main roof to provide additional shading for top floor units, and adopting polystyrene foam insulation in the external walls to reduce heat transfer to units located at the ends of blocks. By 2030, HDB units will also benefit from the use of cool coatings on building facades that will reflect the sun's heat and reduce surface heat absorption.

Beyond physical design, HDB has developed a heat advisory to provide residents with practical tips on keeping their homes cool. These include decluttering to maximise cross-ventilation, appropriate placement of fans, and opening windows and doors to facilitate better air flow.