4 things we have learnt about the true cost of wood burning
Lighting fires in our homes is the single biggest source of harmful small particle air pollution in the UK. Burning wood accounts for the majority (75%) of these emissions, which have been linked to chronic illnesses such as heart and lung disease, lung cancer, diabetes and dementia.
The link between wood burning, air pollution and health is not yet widely understood by the public, and many people are tempted to burn wood because it feels cosy, or due to the myth that it’s environmentally friendly.
There is also a perception that burning wood is a more economical way to heat a home, which feels even more relevant during the cost-of-living crisis. Yet most people who burn wood live in towns and cities, are from more affluent households, and have alternative sources of heating.
We wanted to understand whether burning wood really is a cheaper way to heat a home. So, in partnership with Impact on Urban Health, we commissioned new economic research to investigate the true cost of wood burning.
Download the Relight my fire report
Our research, which was conducted by Dr Donal Brown and Dr Gesche Huebner, looked at the costs of owning a wood burner compared to other sources of heating in real-world scenarios, taking into account installation and maintenance costs, and current and future energy prices over a 15-year period. Here are four of our main findings.
1. Wood burners are almost always a more expensive way to heat a home.
Our economic modelling is based on two typical urban households: a family of four and a retired couple. The findings show that wood burners are almost always a more expensive way to heat your home than gas boilers or air source heat pumps.
The annual cost of using an existing wood burner is 15% higher than a gas boiler in a typical urban household. When a household uses a newly installed wood burner for 20% of its heat, that yearly cost rises to 24% more than a gas boiler. It increases to almost 50% more expensive where a household uses a newly installed wood burner for 80% of its heat.
The only scenario in which wood burners are cheaper is when the wood is free – for example, if you have access to private woodland and can forage your own wood. However, this comes with its own consequences: wood that hasn’t been properly dried or seasoned (ideally for at least two years) or has coatings such as varnish or paint can be extremely toxic when burned.
2. Wood is a more expensive fuel than is often claimed.
Some people may have seen claims in the media that wood burners are cheaper than other forms of heating. However, these claims are based on unrealistically low assumptions about the cost of wood. Our research included a “mystery shopper” exercise to explore the cost of wood from different suppliers. The only way we were able to match previously-quoted costs was to bulk buy large amounts of wood online (which requires space to be stored properly). Most online bulk and single bag purchases were more expensive. Single bag in-person purchases from garages, DIY stores and garden centres were even more expensive, with one garage over four times the cost of wood claimed by industry groups.
3. One wood burner isn’t enough to heat a whole house.
Using wood as the sole source of heating would realistically require two wood burners as they are designed to heat a space, not a whole house. The latest insights from our Clean Air Public Insights Tracker (a quarterly survey of 2,000 members of the public) suggests that 28% of those who use a wood burner or open fire to heat their home use two or more.
One of our research scenarios looks at the cost of using a wood burner to provide 80% of heat in a three-bedroom terraced house. This would require at least two wood burners, and would be almost 50% more expensive than using a gas boiler alone. The research also looked at a scenario with only one wood burner providing a secondary source of heating. This was 15% more expensive using a gas boiler alone.
4. Heat pumps are a cheaper way to heat a home than wood burners, as well as being better for the environment.
Every heating source works more efficiently and economically in a better insulated house. Our research is based on a late Victorian terraced house with loft insulation and double glazing. We looked at modelled installation costs of an air source heat pump including budget to install larger radiators and underfloor heating. This is still at least 6% cheaper than using a wood burner and gas central heating.
It is a common misconception that heat pumps don’t work in older properties such as the one included in the research. However, research by the Energy Saving Trust shows that as long as the system is installed correctly, it will provide more than enough heating even in a poorly insulated house. As heat pumps remain an unaffordable heating option for most UK households, we need to see more support from government for home insulation and the transition to greener heating alternatives.
Another misconception is that wood is a carbon neutral fuel. Yet, for the same amount of heat or energy, burning wood actually releases more carbon dioxide (CO2) than oil or gas. It can take decades for trees to regrow and reabsorb the carbon emitted by harvesting and burning wood and in the meantime, the atmospheric carbon released contributes to climate change. Cutting down trees for fuel also destroys forests, damages ecosystems and leads to biodiversity loss.
Ultimately, wood burners are a luxury we can’t afford in urban areas. There is mounting evidence that wood burning harms your wallet, your health and the planet. This January, we are running the first-ever Clean Air Night, to shine a light on the uncomfortable truth about wood burning. Find out more and how to get involved