Building design rules could change, as the Building and Construction Authority (BCA) begins discussions with industry experts on whether rules on air-conditioning and mechanical ventilation in buildings need to be revised in the light of the Covid-19 pandemic.
The aim 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.
Asked if any set of new rules will apply for existing buildings, the BCA spokesman replied: "We will likely start with new building designs as existing buildings have inherent constraints."
The last revision of the code of practice for air-conditioning and mechanical ventilation in buildings in 2016 included steps to mitigate infiltration of fine haze particles into buildings.
For now, building owners have been given a set of guidelines to enhance air quality. 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 regular cleaning of high-touch points, like door knobs.
Experts interviewed said it is timely to relook building designs to reduce transmission risk in future pandemics. Currently, many of the more modern high-rise office buildings here do not have windows that can open, and are ventilated via central air-conditioning which 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 suggests that buildings adopt a mix-mode strategy that incorporates both natural and mechanical ventilation systems. This is common in temperate climates, he noted, adding that recent advancements in building materials, equipment and design allow this be adopted in tropical climates.
"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 the associate partner of ADDP Architects.
For good indoor air quality, building owners have to step up as they can control the amount of fresh air introduced into a space and the type of air-filtration system used, among other factors, said Mr Lee Ang Seng, managing director of engineering consultancy Beca and SGBC's board secretary.
But he said 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 enhance airflow 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.
A project that is set to blaze the trail is GuocoLand's $2.4 billion mixed-use development Guoco Midtown, located along the Beach Road/Ophir-Rochor corridor, scheduled to be completed in 2022.
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 ultra-violet germicidal irradiation. It will also 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 group managing director, said: "Today, companies understand that and are willing to invest in a safe environment for their most important resource: human talent."