Indoor Air Quality

What Do Indoor Air Quality Standards Look Like In Singapore?

Singapore, the tiny sovereign city-state with a population of only 5.6 million, and one of the most remarkable economies on the planet. When it comes to commerce, Singapore is in the top 10 of almost everything; 5th on the UN Human Development Index, 3rd highest GDP per capita, second most competitive country, and according to the World Economic Forum, the most ‘technology-ready’ nation on the planet.

It is the last accolade that forms the basis of discussing Singapore in particular in terms of building standards. Since 2005, Singapore has shown an incredible drive to develop and incorporate cutting edge technology into building design and functioning. This began with the Building and Construction Authority (BCA) of Singapore developing and releasing the Green Mark rating system for sustainability in buildings.However, the key milestone was in 2008, when Singapore became one of the first and only nations in the world to adopt mandatory ‘green’ building codes.

The BCA’s Green Mark rating system was included in Singapore’s Code for Environmental Sustainability of Buildings; for a building over 2000 m2 to be approved for construction, and it must meet at least the minimum requirements for certification under the Green Mark ratings. This sparked a massive increase in buildings that meet standards for sustainability.


Figure 1: Green Mark Building Projects in Singapore

Green Mark Building Projects in Singapore

The increase in building projects meeting Green Mark certification in Singapore between 2005 and 2013. From Building and Construction Authority article, Singapore: leading the way for green buildings in the tropics (2013).

In the Green Mark system, points are available in multiple avenues ( see figure 2 below).

These focus mostly on energy efficiency. That is not surprising, given that the overarching goal of the Green Mark initiative is to reduce Singapore’s contribution to greenhouse gas emissions, thereby forming the front line in their fight against climate change.

This brings me to the issue of indoor air quality (IAQ) standards in Singapore. On average, only 4 % of the required score for a Green Mark certification can come from the sustainable management of IAQ (Figure 2). However, as I have covered in a previous blog, sustainability cannot be decoupled from the health and safety issues of properly regulating IAQ. Moreover, as noted by Ooi et al. (1998), Singapore’s “tropical climate, densely built environment, and energy conservation requirements pose special constraints to the building industry in ensuring that ventilation and indoor air quality within the fully enclosed offices remain acceptable.” Therefore, in the face of a strong impetus to develope and implement sustainable technology, one must consider how Singapore is dealing with the fundamental issue of IAQ. This led me to ask: what do Singapore’s IAQ standards look like?


Figure 2: Green Mark Benchmarks and Details

Green Mark Benchmarks and Details

The Green Mark rating system’s benchmarks for how many points are needed for certification through to ‘Platinum’ status (above), and the breakdown of the areas where points are available (below). From McArthur et al. (2014). International Sustainability Systems Comparison: Key International Sustainability Systems: Energy and Water Conservation Requirements. CoreNet Global / ARUP, Toronto.

The IAQ standards in Singapore are listed under SS 544 ‘indoor air quality for air-conditioned buildings.’ The definition of acceptable IAQ under SS 554 is, “air in an occupied space toward which a substantial majority (80%) of occupants express no dissatisfaction and in which there are not likely to be known contaminants at concentrations leading to exposures that pose a significant health risk.” This is very similar to the definition of acceptable IAQ listed under ASHRAE Standard 62.1.

SS 554 begins by specifically stating that IAQ is not just an issue of ventilation rates. This is an important statement, as many country codes for IAQ are essentially just a requirement for a minimum ventilation rate. The standard then goes on to acknowledge that proper management of IAQ standard must deal with four broad criteria:

  1.  Location of the building (environment & outdoor air quality)
  2.  Sources and control of indoor air contaminants (listed in Tables 1 (reproduced here), 2 and H.1 in SS 554)
  3.  Ventilation characteristics (minimum rates and recirculation criteria; listed in standard SS 553)
  4.  Nature and use of the building (flexible usage, building materials, hygiene, air tightness, air filtration, occupancy type, the number of people, and maintenance)

The key components of these four main criteria are listed in Table 1 of the standard, which is reproduced here. As is evidenced by the ‘Measurement method / analytical method’ column in this table, SS 554 is not only concerned with providing requirements; it also provides guidance on how to meet and monitor those standards. This is further evidenced by the presence of multiple annexes after the main body of requirements and recommendations. These annexes provide in-depth information on how to meet the requirements, as well as the motivation/rationale behind them. Moreover, the standard is not limited to the aforementioned four criteria. It also provides recommendations/requirements for smoking areas, the construction process, and for renovations.

Table 1:  The recommended indoor air quality standards in SS 554. From SS 554: 2009. Code of practice for indoor air quality for air-conditioned buildings. Building and Construction Standards Committee, Singapore.

The recommended indoor air quality standards in SS 554

Table 1 Continued: 

The recommended indoor air quality standards in SS 554_part2

Note: This table may have been subject to revisions in the most recent release of SS 544: 2016.




Singapore is a remarkable city-state for various reasons. One of the most impressive aspects is its strong drive to become more sustainable. However, in a fast developing city, IAQ becomes a critical issue for health, safety, and comfort. Therefore, how Singapore regulate Indoor Air Quality Standards is a pertinent issue. Looking at their legislation (standard SS 554) has shown that Singapore has been comprehensive in their approach to IAQ regulation.

Not only are the requirements of their standard comparable with the highest international standards of IAQ regulation (such as ASHRAE Standard 62.1), their standard provides a much-needed background for the requirements, as well as guidelines on how to meet and measure them. All of this serves to provide a clear answer to my question: they look like a very thorough treatment of all the aspects of IAQ standard.


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One thought on “What Do Indoor Air Quality Standards Look Like In Singapore?”

  • Dear Mr Cubick,

    me researcher from Germany based in Malaysia and interested to bring the Passive House technology to tropical countries… My recent literature study where I found your blog as a great help underpins the value of a mechanical cross ventilation tool for Indoor Air Quality (IAQ), especially for Singaporean standards as elaborated by you… Our tool that I reinvented for the tropics, is the first and only device that does not use precooled air, but economically directly makes use of the original outside air. Even with the latest technology for A/C (VRV), the device is the only one that can produce controlled fresh air.
    If, like in many cases, natural ventilation is too little (openings, wind speed from outside), our mechanical decentralised ventilation as a cost-saving alternative compared to natural ventilation may play a vital part to decrease the VOCs / contaminants more effectively.
    Out of these VOC- chemical parameters, why did we choose in our own research to focus especially on CO2 (1.) and Formaldehyde (3.)?

    1. Indoor CO2: is also relevant and measured by us
    2. CO: is rare, comes from cooking facilities
    3. Formaldehyde: appears in many shapes (see the list below). Some people are aware of the fact that they are there and could be cancerous (especially carpets)
    4. Ozone: I have no knowledge how frequent it is
    5. Total VOCs: is measured often (AStar) but is just an average value.

    Finally the brief reference to a prolific school project at Punggol Primary School, our first thermooventilation test bed in Singapore with AStar and Bosch:

    Many schools have nowadays more ACs and need to use more airtight enclosures. The more global warming proceeds, the more air conditions need to be used to enable a conducive environment for learning in schools. Commercially there is no solution for integrating split units A/C and dosage fresh air intake for the tropics.

    Thanks again for your precious blog.
    Karl Wagner

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