Building design standards such as air-con rules could be changed post-Covid-19: BCA

The code was last revised in 2016. It includes, among others things, steps to mitigate infiltration of fine haze particles into buildings.
The code was last revised in 2016. It includes, among others things, steps to mitigate infiltration of fine haze particles into buildings.ST PHOTO: JASON QUAH

SINGAPORE - Design standards for new buildings could change as the Building and Construction Authority (BCA) looks into whether rules on air-conditioning and mechanical ventilation need to be revised in the light of the Covid-19 pandemic.

The aim of any such move is to boost ventilation in crowded spaces and improve air quality for situations like public health emergencies, the regulator's spokesman told The Straits Times.

It has started discussions with other agencies and industry experts on whether new rules are necessary, the spokesman said. The regulations are spelt out in the code of practice for air-conditioning and mechanical ventilation in buildings.

Asked if the new rules will apply to existing buildings, the BCA spokesman replied: "We will likely start with new building designs as existing buildings have inherent constraints."

The code was last revised in 2016. It includes, among other things, steps to mitigate infiltration of fine haze particles into buildings.

Meanwhile, building owners have been given a set of official guidelines with precautionary measures that they can take to enhance air quality in their buildings.

These include increasing fresh air intake for better ventilation, carrying out regular air purging and making use of natural ventilation by opening windows.

The guidelines also recommend the use of high-efficiency filters and supplementary air-cleaning devices, such as ultraviolet germicidal irradiation and portable air cleaners to improve indoor air cleaning.

The list, drawn up by the BCA, National Environment Agency and Health Ministry, was issued on May 29 to complement safe management measures, such as the wearing of masks and regular cleaning of high-touch points like doorknobs.

The review of whether ventilation and air-condition rules need to be changed comes in the wake of a statement National Development Minister Lawrence Wong made on June 9, that office and building designs will have to change moving forward.

Experts interviewed said it is timely to relook at the design, operation and long-term maintenance of offices and buildings to reduce the transmission risk during future pandemics.

 
 

Currently, many Grade A office buildings in Singapore do not have windows that can open and close, and are ventilated via central air-conditioning that recirculates air in a confined space, and this could be a way for viruses to spread.

Singapore Green Building Council's (SGBC) first vice-president Tang Kok Thye suggested that buildings adopt a mix-mode ventilation strategy that incorporates both natural and mechanical ventilation systems.

This is common in temperate climates, he noted, adding that recent advancements in the technology of building materials, equipment and design methods allow the approach to be adopted in Singapore's tropical climate.

"Not only does mix-mode offer a means for indoor climate control, it also enhances indoor air quality, creates a healthier climate and improves occupant productivity," said Mr Tang, who is also associate partner of ADDP Architects.

Mr Lee Ang Seng, managing director of engineering consultancy Beca, said one possible way is to create naturally ventilated spaces in the form of green sky terraces and gardens.

For good indoor air quality, building owners have to step up because they can control the amount of fresh air introduced into a space and the type of air filtration system installed, among other factors, added Mr Lee, who is also SGBC's board secretary.

But tenants can do their part as well by installing indoor air quality meters to monitor any additional pollutants released in their offices, which may contaminate the central air-conditioning system.

 
 

They can also use desk fans to encourage air movement and minimise obstruction to airflow by not taping over the air supply grilles on overhead air-conditioning units, said Associate Professor Tham Kwok Wai from the National University of Singapore's Department of Building.

Older buildings will face heavy retrofitting costs if a major redesign is required, said Prof Tham, who is an SGBC board member.

Mr Darren Wee, head of project and development service at real estate consultancy JLL Singapore, agreed. "Piecemeal efforts can be introduced from time to time and up to a certain point, before redevelopment becomes the more beneficial option," he said.

A project that is set to blaze the trail for future office buildings is GuocoLand's $2.4 billion mixed-use development, Guoco Midtown, which is located along the Beach Road/Ophir-Rochor corridor.

When completed in 2022, it will feature a Grade A office tower, two residential developments, a business and social club called Network Hub, and retail podiums.

The development will be fitted with an air filtration system that will filter up to 95 per cent of air pollutants as well as kill bacteria and viruses in the air through ultraviolet germicidal irradiation.

 
 

It will have several contactless features, including lifts that will automatically detect the destination floor of the tenant or visitor when they pass through the turnstiles.

Mr Cheng Hsing Yao, GuocoLand Singapore's group managing director, said: "There are certainly costs involved in ensuring a healthy built environment but the economic impact of an unhealthy and unproductive workforce likely outweighs such costs.

"Today, companies understand that and are willing to invest in a safe environment for their most important resource: human talent."