Heat Emissions from Top Floors of Multi-storey Car Parks with and without Rooftop Gardens
Ministry of National DevelopmentSpeakers
Summary
This question concerns heat emissions from multi-storey car park (MSCP) rooftops and the potential conversion of underutilised parking decks into garden spaces. Assoc Prof Jamus Jerome Lim asked about the effectiveness of rooftop gardens in reducing heat and the limitations involved in repurposing these areas. Minister Desmond Lee stated that HDB studies show green roof systems can reduce surface temperatures by an average of four degrees Celsius. He explained that conversion feasibility depends on factors like structural load, fire safety, utility availability, and broader development plans. HDB will continue intensifying greenery while exploring alternative community uses for suitable MSCP rooftops to benefit local residents.
Transcript
83 Assoc Prof Jamus Jerome Lim asked the Minister for National Development (a) whether HDB has made a study on the amount of heat emission from top floors of multi-storey car parks (MSCPs) that have parking lots; (b) whether gardens located atop such MSCPs emit less heat; and (c) what are the practical limitations that inhibit the conversion of MSCPs with underutilised upper decks into garden spaces.
Mr Desmond Lee: HDB multi-storey car park (MSCP) rooftops are meant to provide unsheltered parking spaces. As part of greenery intensification efforts under the Green Towns Programme, MSCP rooftops that are not heavily used for parking are converted to extensive greenery and community or allotment gardens via the installation of the Prefabricated Extensive Green Roof Tray System, if found suitable. Studies by HDB have shown that this system can potentially mitigate heat gain by reducing surface temperature by an average of four degrees Celsius, as compared to a bare concrete surface.
Not all HDB MSCP rooftops, even if not required for parking, are suitable for conversion to greenery or gardens. The feasibility of conversion depends on considerations, including structural load, the availability of electricity and water supply, potential disamenities to residents, whether retrofitting can meet fire safety standards and development plans for the area.
Besides greenery or gardens, MSCP rooftops could potentially be put to other uses that benefit the community. We will continue to study approaches to make good use of our HDB MSCP rooftops.