Best log burners 2026: what size in kilowatts, what you are allowed to burn, and how much firewood a winter costs

In a smoke control area, wood is not an authorised fuel. GOV.UK puts it plainly: unauthorised fuels such as wood can only be burned in an exempt appliance, and a chimney that lets out smoke can carry a penalty of up to £300, while buying unauthorised fuel for an appliance that is not approved can carry up to £1,000. There is no national map to check: the local council holds it, and its environmental services team is the only place that can tell you.

That makes the Defra exemption a property of the stove, not of the wood. It is also a separate approval from Ecodesign, which every stove sold in Great Britain has had to meet since 1 January 2022 and which says nothing at all about smoke control. None of the seven listings below prints a Defra exemption, so if your address is inside a smoke control area, that is the first thing to ask the seller for, by the exact model, before anything else in this guide applies.

The rule the British trade publishes is a division: room width by length by height in metres, divided by 14, gives the kilowatts. A 5 by 4 metre living room with a 2.4 metre ceiling is 48 cubic metres, so 3.4 kilowatts, and the 5 kW stove that dominates the shelves is already generous for it.

The 5 kW figure is not a marketing convention. Above it, Approved Document J asks for a permanent air vent to outside with a free area of 550 mm² for every kilowatt above 5 kW, non adjustable, in the room with the appliance. In a dwelling built to a modern air permeability of 5.0 m³/(h·m²) or better, the same 550 mm² applies to every kilowatt of rated output, not just the excess. On top of that the hearth has to reach at least 300 mm in front and 150 mm to each side and be at least 840 by 840 mm overall, and a carbon monoxide alarm is a legal requirement in the room.

All of it is signed off either by a building notice to the council or by a HETAS registered installer self certifying the work. That is the part of the purchase that turns a stove into a project, and it is decided by the one number every listing does print.

Read down that column and the British market explains itself. A vent is a hole cut through an outside wall that cannot be closed, in the room you are trying to make warm, and the arithmetic doubles between a 6.7 kW stove and a 9.5 kW one. That is why the shelves are full of 5 kW appliances and why a Spanish or Italian listing of 16 kilowatts, which is perfectly normal for a stone farmhouse, is a different proposition here.

If you are hesitating between two outputs, we would take the smaller one, and not to save money: the larger stove spends the evening throttled down, which is where a wood fire makes the most smoke, and it brings the vent arithmetic with it for the life of the house. Where the extra kilowatts genuinely earn their place is an old, solid walled, badly insulated property, and that is a description of the building, not of the room.

HETAS puts a typical British household running a stove on cold evenings at somewhere between 1.5 and 3 cubic metres of seasoned hardwood for a winter. That is a useful anchor and it hides the trap: logs here are sold by the loose cubic metre, the builder's bag or the crate, and a loose cubic metre settles into roughly 0.60 cubic metres once it is stacked. The energy is in the stacked volume, so the number you are quoted and the number that heats your house are not the same number.

What a stacked cubic metre holds is not a matter of opinion. Hardwood at 20 % moisture is about 1,700 kilowatt hours and softwood or a mix about 1,300, a 31 % difference in volume for the same heat. A British cross check agrees: the Wood Fuel Co-operative puts a tonne of logs at 20 % moisture at around 4,100 kilowatt hours, which lands in the same place once you convert.

Left exactly as it opens, at 10.2 kilowatts and 78 % efficiency for six hours a day across five months, the calculator returns 6.9 stacked cubic metres, about 18 kilos a day and 13.8 metres of wall at a metre high. That is four times the HETAS figure, and the gap is the whole point: their 1.5 to 3 cubic metres describes a stove lit on cold evenings, and six hours a day for five months describes a stove used instead of the heating. The difference between those two houses is roughly four cubic metres of wood and eight metres of wall, and it is decided the day you pick the output, not the day the logs arrive.

Wood fuel in England stopped being an unregulated purchase on 1 May 2021. Below 2 cubic metres it has to be certified, above it, it does not, and the threshold is doing more work than most buyers realise: a 2 cubic metre load bought loose is about 1.2 cubic metres once stacked, which is close to a whole winter by the HETAS figure. The seasoning still has to be done by somebody, and above the threshold that somebody is you.

A log burner is usually sold as the cheap way to heat a room, and on the published British numbers that is not what it is. Nottingham Energy Partnership has compared domestic fuel costs monthly since 2007, on a medium sized home of about 12,500 kilowatt hours of annual heat demand, with appliance efficiency and standing charges already inside the figure. In its September 2026 table, kiln dried logs cost more per kilowatt hour of delivered heat than mains gas, and about the same as an air source heat pump.

That does not make a stove a bad purchase. It makes it a different purchase: a log burner heats the room it is in, it keeps working when the power goes off, and it is the only one of these that does not send a bill. What it is not is a way to undercut the gas boiler.

Every solid fuel room heater placed on the market in Great Britain since 1 January 2022 has had to clear one efficiency floor and four emission ceilings. The floor is the one that gets misquoted: it is 65 % seasonal space heating energy efficiency, not the 75 % or 80 % you will read on comparison pages, because those are net figures from the data plate and the two scales do not meet. The Stove Industry Association describes the practical consequence in one line: to clear 65 % seasonal, a closed stove needs roughly 75 % net, about ten points higher.

Knowing which scale you are looking at is the difference between comparing two stoves and comparing two units of measurement. The percentage on a listing is almost always the net one, and it is the one the calculator above wants.

The second question Google shows under this search is what to look for when buying a log burner. The short answer is six figures, and four of the six are published by obligation somewhere the listing is not: in the manual and on the manufacturer's own website. Two are not defined by any rule at all, and one of those two is the number listings print the most.

Tick what the listing in front of you actually prints and the checker returns, figure by figure, what you can decide with what you have, what you still cannot decide, and where the missing ones are published.

Read the seven against the British rules rather than against each other and the order changes. The highest output on the list is the one that prints the most figures, and it is also the one that forces the biggest hole in the wall, so it stops being the obvious answer for anyone whose room the volume rule sizes at three or four kilowatts.

We would take the 8.6 kilowatt one, and the reason is a number rather than a feeling: it is the only listing of the forty that names the 2022 Ecodesign requirements in its own title and the only one that declares class A+ instead of A, and at 8.6 kW the vent the rule forces is 1,980 mm² rather than the 6,204 mm² of the 16.28 kW model. That is a smaller commitment to the fabric of the house for the same evening of heat in a normal living room.