What did we find?
1. Wood burning is more expensive than central heating
Wood burners are more expensive than both gas boilers and air source heat pumps in almost every scenario.
For example, even when a wood burner is pre-existing in a home (meaning that both the purchasing and installation fees are excluded), the annual ownership costs of burning wood are still 15% higher than a gas boiler, at £1,866 – £2,042.
We also found that using a new wood burner for 20% of heat in a home incurs annual costs 24% higher than a gas boiler, at £2,028 – £2,204 per year.
And when using two newly installed wood burners for 80% of heat in a home, the annual cost is 47%- 48% more than exclusively using an existing gas boiler, at £2,433 – £2,614 per year.
Due to increases in the cost of wood fuel, the only scenario in which burners are cheaper is when wood is sourced for free. However, free wood (like scrap wood that hasn’t been properly dried or seasoned) is often the most toxic and is extremely harmful, not only to the health of the people burning wood but their neighbours too. Indeed, in winter of 2022-23 arsenic was found in London’s air, raising concerns that people are burning waste wood from construction sites while unaware of the serious health risks.
2. Burning wood also has hidden health costs
Not only is burning wood more expensive to the households that choose to burn, but it also has hidden costs for everyone in society.
These are calculated by the Department for Environment Food and Rural Affairs (Defra), using what are known as “damage costs”*. Damage costs could include asthma incidence, hospital admissions for respiratory issues, and damages to buildings.
Put simply, any value showing damage costs refers to a cost to society.
For example, even when people who burn wood use an eco-stove and well-seasoned wood, there are damage costs of £9,060 for a family of four and £8,171 for an older couple. This calculation is based on using a wood burner over a 15-year period, which supplies 80% of the heat.
These costs rise to £39,243 (for a family of four) and £39,106 (for an older couple) respectively if the households use damp wood in an older stove.
3. Wood burning isn’t a more sustainable form of heating
As well as perceptions that burning wood is a cheaper way of heating a home, some people believe that burning wood is a more environmentally friendly form of heating.
However, wood burning creates more harmful carbon dioxide (CO2) emissions when compared to other forms of heating and it’s not possible to reproduce trees fast enough to offset that CO2. It takes years, decades or even a century or more for the CO2 from wood burning to be fully reabsorbed by the growing ecosystems, depending on the forest management and biomass source.
What about people who rely on wood burning for heat?
We understand a minority of households – particularly those in rural areas and some people in urban areas like those that live on houseboats – often rely on burning wood to heat their homes.
Indeed, 8% of the households who burn wood do so out of necessity, though evidence for Defra shows most of these households live rurally and on lower incomes, compared with the populations who tend to burn wood in cities.
While we at Impact on Urban Health would like to see a reduction in wood burning, particularly in densely populated urban areas where most people burn for pleasure, we need to do more to support a transition to sustainable, and affordable heating options across the board.
I’m concerned about wood burning in my town or city
Our work is currently focused on communicating the links between burning wood, air pollution, health, and inequality. To that end, we recently published a communication toolkit for councils and campaigners. That toolkit describes our market research into the motivations behind wood burning and the most effective ways to raise awareness and change behaviour.
We hope increased awareness of how burning wood contributes to air pollution will lead to fewer purchases of wood burning stoves, more consideration by those who already have wood burners, and eventually restrictions on wood burning in cities with support or incentives to stop.
Ultimately, we would like to see future interventions from councils and government, whether they include warnings at point of sale, bans on burning during air pollution alerts, or outright bans on burning wood in urban areas.
You can learn more about campaigns to reduce wood burning in cities, including Global Action Plan’s ongoing work for Clean Air Night 2024 and Mums for Lung’s resources on wood burning here.
*“Damage costs” refer to a set of impact values, which are measured per tonne of emission by pollutant and then calculated using a complex impact pathways analysis, which accounts for things like asthma incidence, hospital admissions for respiratory issues and strokes, and damage to buildings. It’s important to understand damage costs when thinking about the costs of burning wood, both in terms of its effect on health and the economy.