The X files:

Is air quality the new carbon?

The believer.



For at least the last 20 years the construction industry has made significant progress in understanding and reducing the impact of buildings on the world’s carbon emissions. Regulation has been introduced and assessments made, all with the aim of reducing carbon dioxide emissions from buildings – and that’s been incredibly important.

But there has been a massive shift in what a healthy ‘sustainable’ building actually means. No longer is it just based upon its carbon emissions. There is a bigger, more important – and potentially fatal – issue at play. This issue is seen as so important to regulatory bodies that there’s talk of recommendations being introduced to actually increase carbon emissions in buildings in order to counteract this new evil.

This evil? ...All contained within the air we breathe. Air quality is the new carbon. The ‘baddies’ in our air include VOCs (volatile organic compounds: gases from certain solids or liquids), NO₂ (nitrogen dioxide) and PM2.5 (particulate matter). The list is extensive and the solution is complicated.

No safe limit

Both CO₂ and particulate matter (PM), alongside a few other ‘baddies’, are recognised sources of poor air quality. According to recent research and evidence from Harvard University, in addition to causing illness, increasing the level of CO₂ within a building can significantly reduce productivity, as cognitive ability to make strategic decisions is diminished. This calls into question the suggestion that CO₂ levels could be allowed to rise within our buildings to counteract impacts of poor air quality. We cannot solve an air quality problem by exacerbating a ventilation and climate-change issue.

The sceptic.



While air quality (indoor and outdoor) plays a crucial role in promoting our general health and wellbeing, other factors all play equally fundamental roles, including: access to daylight, water quality, thermal comfort, acoustic performance of spaces, agile work settings etc. According to the World Health Organisation: “health is a state of complete physical, mental, and social wellbeing, and not merely the absence of disease or infirmity”. Therefore, looking beyond factors that impact on just our physical wellbeing, our buildings must support the total person – our complete wellbeing.

Without a doubt, any new or universal metric for defining/benchmarking what a sustainable building design could look like must at least cover all three aspects of wellbeing – especially given the shift of priority towards wellbeing across all levels in the industry. Reductive strategies and approaches with regards to building design and tackling environmental sustainability have only taken us so far. We must now embrace a more holistic approach if we’re to drive natural, human, social, physical, and economic capital; that is, securing and towing a sustainable trajectory.

Air quality, as an isolated measure certainly can’t be the new carbon. We know “healthy is the new wealthy” and, therefore, I dare say “health and wellbeing is the new carbon”.

The health and wellbeing argument

The impact of these particulates has long been discussed but it’s rapidly gaining traction as more and more evidence comes to light of the negative impact of bad air quality. For instance, PM2.5 is so bad for your health that there is no safe limit below which it is OK to breathe. Similarly to regulations for a building’s maximum energy consumption, I believe we’ll be seeing limits on particulates in the air inside these spaces very shortly. And, be under no illusion, this will impact our designs. A recent study by UCL implies it’s impossible to have a simple naturally ventilated building in the City of London and keep within EU guidelines for PM2.5 levels. In fact, some predict CO₂ levels should be allowed to rise above current ‘safe’ limits within a room to reduce the impacts of the worse air quality from outside. All of this is likely to increase energy-use and hence carbon. The argument is there – air quality is the new carbon.