Paul Williams from Domus Ventilation addresses the critical need to remove air pollutants from homes, and how the Healthy Homes Bill might just hold the key to unlocking cleaner air for all
In May of this year, the Healthy Homes Bill received its first reading in the House of Lords. The Bill aims to transform the regulation of the built environment by making provision for the delivery of healthy homes and neighbourhoods that support the physical, mental and social wellbeing of residents.
The Bill outlines a wide range of key aspects that impact the health of a home, including fire safety, liveable space and adequate storage, natural light, inclusivity, accessibility and adaptability. Further aspects include reduced carbon emissions and resilience to climate change, security, noise and light pollution, indoor and ambient air pollution, and thermal comfort, as well as access to sustainable transport and walkable services.
It’s a long list, and while advances have been made in a number of areas, we are far from where we need to be if we are to deliver truly healthy homes. This is certainly the case when it comes to the matter of air quality, both internal and external.
How clean is our air?
In 2021, the UK was found guilty by the European Court of Justice of “systematically and persistently” breaching air pollution limits. The Government’s latest data shows that NO2 limits are being exceeded in 33 out of 43 air quality assessment zones. The other main offender when it comes to air pollution is PM2.5 (concentrations of particulates). The legal limits in the UK are set nearly twice as high as the level that is recommended by the WHO. Even with this raised rate, over 35% of local authorities had areas with unsafe levels in 2018, which equates to more than 22 million people living in areas with unsafe levels of PM2.5.
Exposure to air pollution is a serious threat to health, with known links to lung disease, heart disease, dementia and strokes. According to NHS England, 30% of preventable deaths are due to non-communicable diseases specifically attributed to air pollution.
And it’s not just our physical health that suffers, but also our economic health; Defra estimates the economic cost from the impacts of air pollution in the UK at between £9bn and £19bn every year.
Planned environmental, transport and clean air policies are in place which could reduce air pollution levels to within the WHO recommended interim target by 2030, but only if they are implemented now, and in full.
The danger within
External air pollution entering our homes is not the only issue to contend with when it comes to indoor air quality. Building fabric, such as insulation – and countless building Products – emit potentially harmful pollutants into our air. Volatile organic compounds (VOCs) are some of the most common as they are found throughout building products, including paints and finishes, carpets and flooring, pressed wood products, and adhesives.
The Healthy Homes Bill states: “all new homes should not contribute to unsafe or illegal levels of indoor or ambient air pollution.” This translates as ‘choosing healthier building materials and products.’
There is currently a distinct lack of standards for the control of indoor pollutants, although the recently revised Building Regulations Approved Document F now includes guidance on indoor air pollution, including exposure limits and times for carbon monoxide (CO), as well as NO2, formaldehyde (CH2O) and TVOC.
Removing air pollution from homes
As laid out in the Healthy Homes Bill: “all new homes must be built to minimise, and where possible eliminate, the harmful impacts of air pollution on human health and the environment.”
In order to achieve this, good ventilation is essential to disperse pollutants. As recognised in Building Regulations, this is best achieved through mechanical ventilation systems, with the most effective being Mechanical Ventilation with Heat Recovery (MVHR). These bring fresh air into the home and extract stale air, along with the pollutants.
However, if properties are located in areas with high pollution levels, the MVHR systems are actually bringing polluted air into the home and, although they come equipped with standard filters, these can only do so much. Building Regulations advice is to locate intake grilles away from the direct impact of the sources of local pollution, but this is not always possible or effective enough. Installing a powerful carbon filter to the MVHR system would be a more effective approach. One available product for example is applied on the supply leg of the ducting, to prevent up to 99.5% of NO2 pollution from entering a home.
Mechanical ventilation systems not only address air quality in terms of removing pollutants, but they are also highly effective at preventing condensation and subsequent mould formation; dealing with overheating in the more airtight new homes we now build; and even in reducing airborne virus transmission. So even if we meet all our goals and bring external air pollution down to WHO acceptable guidelines, mechanical ventilation remains an important aspect of a healthy home.
The next step
The Healthy Homes Bill is now at Committee stage, so has a long, long way to go and, as a Private Members’ Bill, will face an uphill battle. But if it is able to survive the journey, it could be a genuine game changer in how we approach and regulate our built environment.
Paul Williams is product manager at Domus Ventilation