While we’re often not aware of it, the air quality in our buildings and homes can have one of the biggest impacts on our health. Air pollution is estimated to cause about 29% of lung cancer deaths, 43% of lung disease deaths, 25% of heart disease deaths and 24% of stroke deaths, and is even linked to greater risks of dementia – and yet most of us probably don’t think about it on an average day.

Despite work being done to reduce pollution in the UK, we still have significant problems with outdoor air quality. Whether you live in Brighton or Bradford, Southampton or Swansea, chances are if you live in a major UK city then the levels of harmful particulate matter in the air exceeded the WHO recommended ‘healthy’ average levels in 2022. Perhaps even more shockingly, last year 97% of UK schools were found to exceed safe levels of air pollution, meaning that children are spending up to 50 hours a week breathing in potentially toxic compounds.

One thing is clear therefore: we have to do more to protect people from harmful outdoor air. Unfortunately, in recent years the push for more sustainable buildings has led many to push for ‘natural ventilation’ – relying on simply opening windows to bring ‘fresh’ air into buildings. However, this does not present a viable solution in many cases when it comes to promoting health. Properly ventilating buildings is absolutely essential, and if not done properly we can easily see a buildup of harmful chemicals inside buildings (known as VOCs), high levels of carbon dioxide (which can cause a range of issues from headaches to reduced cognitive performance), and issues with condensation and mould, which can be potentially deadly as we saw in the recent case of Awaab Ishak. With modern housing often lacking dedicated clothes drying spaces or utility rooms, many people are forced to dry clothing on racks in their living rooms or bedrooms, further enhancing the risk of such issues – while a recent study found that the pollutants given off by simply cooking a roast dinner can cause air quality worse than that of Delhi, the world’s sixth most polluted city.

However, if the air quality outside of our buildings is also poor, then opening windows for ventilation can actually cause more problems for occupants as air full of harmful chemicals is dragged into spaces. For this reason, we at Ekkist strongly believe that in urban spaces natural ventilation simply isn’t a suitable approach anymore. Instead, all new buildings in these locations should be fitted with mechanical ventilation systems (such as MVHRs), with high quality particle filters to ensure that the air our occupants are breathing is not doing them significant harm.

Critics may argue that mechanical ventilation is harmful to the environment, as it requires increased energy loads. This is a fairly simplistic view, especially when we compare it to what typically happens in naturally ventilated homes in winter. As this country is fairly cold for six months of the year, people who live in such homes are faced with two choices: don’t open windows, and put yourself at risk from poor indoor air quality, or open windows and turn the heating up – and most heating in the UK still comes from gas, which is generally less clean than electricity (especially as the grid becomes increasingly greener).

Ironically therefore, while it may seem counter-intuitive, there is an argument to be made that natural ventilation can actually be worse for the environment than mechanical in a colder country like ours, especially when we consider that many people have never been taught how to use windows to ventilate their homes effectively either.

There are strong arguments instead to take more of a Passivhaus approach: a tight, well-insulated building envelope, supported by mechanical ventilation. This philosophy also helps to tackle issues like overheating and extreme cold, which between them account for over 60,000 excess deaths in the UK each year. Of course it is also important to supplement any mechanical systems with green sources of energy, but as these become cheaper and more efficient, and our grid continues to move towards being carbon neutral, there is no reason why we can’t support both human health and the planet.

At Ekkist, we therefore always advocate for approaches like this, ensuring greater control over both indoor air quality and energy use. Whether it is through using tools like our Healthy Homes Checklist, The WELL Building Standard, or The Home Quality Mark, we champion design that gives occupants the best chance at breathing clean, healthy air and living healthier lives. Additionally, air-specific certifications like AirScore can help developers be more transparent about air quality.