Written Answer by Ministry of National Development on sound-proofing in HDB flats

Oct 2, 2018

Mr Dennis Tan Lip Fong: To ask the Minister for National Development 

(a) whether the level of sound-proofing in our HDB BTO flats has declined in recent years with the use of non-concrete walls and with the more recent flat or building designs; and

(b) whether the Ministry has any plans to improve the level of sound-proofing in new BTO flats.


HDB buildings are constructed using reinforced concrete in accordance with the prevailing building codes and industry norms. This ensures that our buildings are structurally safe and suitable for occupancy. While the design of HDB flats have undergone some changes and improvements over the years, such changes in design do not reduce the level of sound-proofing in the flats.

As part of efforts to improve overall construction productivity, since November 2014, BCA has required all residential non-landed developments to use non-concrete drywalls for internal partitions, except for wet areas such as the bathroom and kitchen areas. The drywall systems used in BTO developments, which comprise a metal framework enclosed with gypsum plaster panels on both sides and filled with sound insulation material, provide comparable acoustic insulation as concrete walls of similar thickness.

To elaborate, the Sound Transmission Class (or STC) is used to rate the acoustic performance of interior partitions. It is the decibel reduction in noise a partition can provide, with a higher STC value given for better acoustic performance. Interior walls using bricks or concrete have STC of about 40, which is considered suitable for residential units. The drywall systems used in new BTO developments since 2014 have a STC of at least 45, which is even higher.

Notwithstanding the flat design or the material used, in a high-density living environment like a HDB block, it is also important that residents do their part by being considerate, such as through keeping the noise level down especially late at night, so as to provide a pleasant living environment for all.