Breathing rooms: pollution and the property market

Air quality could become as important to homebuyers as price per square foot, proximity to schools and transport links.

Price per square foot, school catchment areas and good transport links have long featured at the top of most prospective homeowners’ checklists. Now, however, there is an altogether less visible factor in house-hunters’ decisions about where to move: the air they breathe.

When Dr Animesh Singh began trawling property listings for a bigger house in the well-to-do west London suburb of Chiswick to accommodate his growing young family, he quickly found, to all intents and purposes, his dream home.

The five-bedroom semi-detached house boasted a master-bedroom suite with a walk-in wardrobe and balcony, a tastefully redone kitchen and dining area, and a 30-metre garden — perfect for his playful, infant sons.

But take a right turn out the driveway and within seconds you’re on the Great West Road: a traffic-choked, six-lane highway that oozes fumes from the 130,000 vehicles that use it on a daily basis to travel to and from Heathrow airport and beyond. The road falls just outside London’s expanded ultra-low emission zone (Ulez), meaning even the most polluting diesel cars are still allowed on it free of charge.

The listing touted the “immediate road access” from the property, but to Singh and his wife, both of whom are NHS doctors, it was a turn-off. “Air pollution may be invisible, but that doesn’t make it any less of a priority than the number of bedrooms and bathrooms,” he says, adding that he did not want his children “to grow up with dirty air being piped straight into their lungs”.

Exposure to polluted air — generated by exhaust emissions as well as the tiny debris created by tyre and brake wear — has been linked to countless health problems, including asthma, heart disease and even depression.

“[Air pollution] does damage to every organ of our body,” says Dr Audrey de Nazelle, a deputy director of the Centre for Environmental Policy at Imperial College London. “Without even realising, we all probably never reached our full potential of lung and brain development because of it.”

For homebuyers, particularly parents of young children, therefore, air quality is weighing more than ever on their decision about where to move. Cleaner air is now on par with proximity to family and friends, and access to public transport, as a motivation for moving house, according to Strutt & Parker’s annual Housing Futures survey.

The growing interest in air quality has big implications for the property market, according to experts. Some families have decided to swap the city smog for the fresh country air, while others have opted to stay put but have become more exacting about their property search. The level of air pollution is fast becoming “a new red line” for city dwellers looking to move, according to Henry Pryor, a London-based buying agent for high-end homes.

When Pryor started buying and selling homes in the mid-1980s — at which point London’s air quality was even worse than today — “nobody gave a toss about what they were breathing while sitting on the sofa”, he says. But the rise of the environmental movement and a newfound emphasis on health and wellness sparked by the pandemic has changed homebuyers’ attitudes.

“Back then, you could smoke in pubs and on the Tube, but now we’re all much more aware of the merits of protecting yourself from toxic air. Nowhere is that more important than in the home where you raise your kids and spend most of your time,” says Pryor, adding that most of his clients ask about pollution levels.

Roarie Scarisbrick, a prime London buying agent with Property Vision, agrees. He says clients “shy away” from main roads as much because of the dirty air nowadays as the noise levels. Typically, their judgment is based on “the sight of gas guzzlers going up and down” the road, according to Scarisbrick, but he expects buyers will increasingly take “a more studied, scientific approach” by consulting air pollution indices before looking around a property.

Dr Singh did exactly that: poring over multicoloured pollution maps of the Chiswick area before booking a property viewing, discounting any bright red hotspots. He watched the asking price of the house just off the Great West Road slide from £2.2mn to £1.75mn over the past few months. He surmises that other buyers were turned off for the same reason he was. The home is now under offer for about £1.8mn.

In September last year, the World Health Organization raised the bar for what qualifies as safe pollution levels under its air quality guidelines. Consequently, every one of the world’s 50 most populous cities, for which there are data available, fall foul of the new target for PM2.5 (the measure of fine particulate matter produced by road surface abrasion and construction sites) and the target for nitrogen dioxide, or NO2 (a gas expelled by car exhaust pipes), according to data compiled by Airly, an air quality sensor company.

However, pollution levels vary dramatically from street to street. Some 1.2mn Londoners were lucky enough to live in areas that met the WHO guidelines for PM2.5 in 2019, according to Imperial College London research — the vast majority were not.

Estate agents and online property portals have been slow to accommodate the Londoners with the inclination and financial freedom to search expressly for a new home in the less polluted corners of town. None of the biggest companies in the sector disclose pollution levels to customers on their property listings.

Rightmove, which has an 83 per cent market share in the UK, indicated it was open to the idea, but is yet to do so. Air pollution is “going to become more important to home-hunters over the coming years, therefore it’s a data set we’d consider introducing in the future”, the property portal told the FT.

SearchSmartly, a property portal start-up that has helped hundreds of clients complete their move and is partnered with 550 estate agents, having added nearly 200 in the past year, hopes to fill that gap in the market. Most of its 100,000-plus listings carry an air quality rating of one to five, which is accompanied by a stark warning about the elevated mortality risk from breathing air that breaches the WHO limits.

Taha Dar, SearchSmartly’s founder, says homebuyers value being given the “honest truth” about “the biggest purchase of their lives”. “Buying a home is all about trade-offs: if you want more space and fresh air, you might have to face a longer commute. The more information, the easier it is to balance those competing priorities,” he explains. One in every 10 people who have used the app in the past year checked the air quality rating, a six-fold increase on the year before, according to Dar.

The lethal impact of air pollution first hit home for many Londoners with the death of Ella Kissi-Debrah, a nine-year-old who suffered a fatal asthma attack in 2013. The tragic death of the young girl, who lived just off the Lewisham stretch of the busy South Circular Road, marked the first case worldwide in which air pollution was listed as a medical cause on a death certificate, following a coroner’s inquiry in December 2020.

Polling carried out by London Councils, the city’s local government association, in the same year found that 45 per cent of Londoners said air quality affected where they chose to live, up from 38 per cent in 2016. Pollution levels particularly influenced the decision of people with health conditions and those with children.

“We take a lot of effort to avoid exposing ourselves to passive cigarette smoke, so why should we have this other poison forced down our airways,” says Jonathan Grigg, professor of paediatric and respiratory medicine at London’s Queen Mary University, who provided expert testimony in the Kissi-Debrah case.

“If you move from 100m from a main road to 500m away from a main road, that will reduce your risk of these pollutants harming your body. I expect that’s something people looking for a family home are willing to pay a premium for,” says Grigg, adding: “Of course, many families don’t have that choice.”

In 2019, the Central Office for Public Interest (COPI), a pressure group, launched addresspollution.org, a website that provides users with a free air-quality report for their address. The idea behind the website was to increase awareness about urban air pollution. Homebuyers searching for properties in the UK capital’s pollution hotspots were urged to push for a discount of up to 20 per cent on the asking price.

Separate studies carried out in Nantes in France and Oakland, California, both of which are coastal cities with relatively good air quality, found that pollution levels did not influence house prices from one neighbourhood to the next. In Oakland, researchers discovered to their surprise that the more polluted districts were associated with higher house prices.

Humphrey Milles, COPI founder, thinks this is largely down to air quality data being “hidden” from homebuyers. “If you are an estate agent and you know there is a really nasty neighbour or a flood risk or Japanese knotweed . . . you tell the buyer about it, so why does the same not apply to pollution?” adds Milles.

In England and Wales, the only pollutant that sellers are obliged to disclose is the levels of radon, a gas typically produced by decaying granite rock, which has been linked to lung cancer. Despite information about radon being tucked away on page 11 of the TA6 conveyancing form — a bureaucratic hurdle that all sellers have to clear — research from the London School of Economics suggests the relatively unknown indoor air pollutant suppressed house prices in at-risk areas by 1.6 per cent.

Greater transparency about traffic-related air pollution could “shake up house prices even more dramatically”, says Sefi Roth, assistant professor of environmental economics at the LSE who co-authored the study. “People tend to prioritise health ahead of almost everything,” says Roth. “This might be what estate agents are running scared of.”

Milles hopes that by the middle of the decade this information will be mandatory — and that the growing public awareness will force governments to do more about environmental change.

“This isn’t just a poor man’s problem,” he says. “People may not care about environmental issues but they certainly care about the value of their property. If things are going to start impacting the value of properties, then people start to listen.”

Low-emissions schemes are already having an effect. Between 2016 and 2019, the number of Londoners living in high-risk areas for NO2 fell from more than 2mn to 119,000. In 2021, the scheme is expected to reduce NO2 levels by 30 per cent across the city. Sadiq Khan, London’s mayor, revealed plans earlier this month to expand the scheme across the whole city by the end of 2023.

The speed of low-emission schemes cleaning up urban air pollution could soon mean the biggest bargains in town could be found in the current pollution hotspots. Pryor predicts the “best investments” in London may counter-intuitively be the more traffic-clogged high streets.

The transition to electric cars is also already well under way: there were more units sold in March than in the whole of 2019, according to the Society of Motor Manufacturers and Traders. The UK government plans to force carmakers to sell majority electric cars from 2028 onwards, ahead of a total ban on emitting vehicles in 2035.

“If we carry on on the current trajectory, removing people and petrol from our roads, then in a very short time, houses which were thought to be contributing to adverse health effects may become not so bad. Living next to a main road may become attractive,” says Prof Grigg.

But that was too long to wait for the Singhs, who are getting settled in their new home, nestled several streets further back off the Great West Road, after closing on the deal at the end of March. “The garden’s smaller, but the air’s a lot cleaner,” says Dr Singh.