Engineering Advancements in HDB Flats

17 Mr Chong Kee Hiong asked the Minister for National Development what technological improvements in engineering and material sciences have been incorporated into the building of our HDB flats in recent years to ensure enhanced structural integrity, higher noise insulation, improved ventilation and heat reduction.

The Senior Minister of State for National Development (Mr Desmond Lee) (for the Minister for National Development): Mdm Speaker, over the years, the Housing and Development Board (HDB) has enhanced the building performance and liveability of our housing estates by leveraging on technology during the development of our HDB flats.

To enhance a building's structural performance, HDB keeps abreast of improvements in concrete technology and introduces new materials after they have been tested for performance and cost effectiveness. For example, we have been continually improving the grade of concrete used in HDB developments. The higher performance concrete is denser and more impermeable to water, thereby mitigating problems of water leakage and spalling concrete.

About a decade ago, HDB also started installing structural health monitoring sensors in key structural columns of new HDB developments. These sensors help engineers better understand the behaviour of building structures through its life cycle and continually monitor their structural integrity.

Separately, over the years HDB has been developing in-house expertise in urban environmental modelling (UEM) to better take into account urban environmental parameters, such as wind flow, solar irradiance, shading and noise, at the planning and urban design stage.

HDB started using UEM some years back in the planning and design of the Build-To-Order (BTO) development known as Punggol Treelodge, and is now using UEM on a much wider scale in BTO projects in Bidadari and Tengah. Through model simulations, we are able to better understand how different housing typologies, building layouts and orientation, greenery provisions and road networks affect wind flow, solar heat gain and noise level, enabling us to refine our plans to improve liveability.

To mitigate noise impact in buildings, advanced noise modelling is used to guide the orientation of HDB blocks and the placement of physical barriers to enhance aural comfort. Greenery features deployed at strategic locations identified through solar irradiance analysis help to reduce ambient temperatures as well as reflected heat and glare. The placement of communal facilities is also similarly optimised by locating them in areas which tend to be shaded.

HDB will continue to enhance its macro scale simulations to improve the planning and urban design for all new towns and estates. HDB will also continue to tap on advances in building technology and materials and work collaboratively with various institutes of higher learning and research institutes to develop even more environmentally sustainable and cost-effective solutions for our HDB developments.

Mdm Speaker: Mr Chong Kee Hiong.

Mr Chong Kee Hiong (Bishan-Toa Payoh): I thank the Senior Minister of State. To counter the tropical heat, would ventilation louvres be installed to shield units from direct sunlight and facilitate cross ventilation, because such louvres have been installed in some condominiums and public buildings, such as the halls at Nanyang Technological University.

The other supplementary question has to do with countering noise transmission between floors, a common complaint among HDB residents. What kind of floor impact noise reduction underlayment does HDB intend to use to improve the situation?

Mr Desmond Lee: Mdm Speaker, as I said earlier, HDB does modelling in order to determine the design and layout of blocks and also the design and layout of individual units. I will take back the Member's suggestion on the placement of louvres to improve cross ventilation, though I believe the building engineers may already have considered some of these suggestions.

The other question that the Member raised was regarding noise impact between floors. I am sure all of us in this House will, from time to time, get feedback about neighbours or neighbours' children on the upper floors jumping around or playing certain kinds of games that may cause noise to be transmitted below. So, this is one of the common challenges that can impact the quality of living in built-up urban environments and high-rise living. So, mitigating noise issues, such as these, is an essential part of HDB's ongoing efforts to provide a better living environment for the comfort of residents.

With advancements in building technologies as well as in materials science, HDB has been tapping on these advancements in the market. HDB has also reached out to Institutes of Higher Learning and research institutes to work collaboratively on solutions that could reduce noise transmission between floors. So, it is design and also materials science.

Mdm Speaker: Mr Ang Wei Neng.

Mr Ang Wei Neng (Jurong): Mdm Speaker, I am glad that the Senior Minister of State has said that HDB uses modelling to build flats so as to reduce noise pollution and also to increase ventilation. However, we see a lot of new flats are built facing the main road or the Pan Island Expressway (PIE). I used to stay in a flat that faces the main road as well as the Mass Rapid Transit track. It is very noisy! Can HDB consider that as a factor as well as having more flats that are North-South-facing to improve ventilation?

Mdm Speaker: Keep the reply short, please, Senior Minister of State.

Mr Desmond Lee: Mdm Speaker, in my earlier reply, I said that HDB uses modelling. Certainly, in the design of the new estates, including some of those that front, say, expressways, these are taken into account to ensure as much noise-buffering as possible. Apart from appropriate planting, there is also the need for proper buffering and distance away from major transport pathways, and also the design and facing of buildings. For example, as far as possible, we try to put the end of the block to face some of these. But we continually look at these plans and try to ensure that, as far as possible, in a very dense and highly built-up environment in Singapore, where land is very scarce, we try to design both the units but also the estate in a way that takes into account the comfort of residents.

3.00 pm

Mdm Speaker: Order. End of Question Time. The Clerk will now proceed to read the Notices of Motions.

[Pursuant to Standing Order No 22(3), provided that Members had not asked for questions standing in their names to be postponed to a later Sitting day or withdrawn, written answers to questions not reached by the end of Question Time are reproduced in the Appendix.]