If you’re installing a new woodburning stove or renovating a chimney or fireplace, it will need to comply with Building Regulations.

More than a million homes in Britain now feature a wood-burning stove. It’s one of the hottest interior design trends. All work to install a stove or renovate a chimney must meet UK Building Regulations. These set out the minimum standards to ensure the chimney or flue functions safely and effectively. The full details can be found in the Approved Document J (England and Wales) or Handbook 2 (Scotland) or Technical Booklet L (Northern Ireland).

Hiring a HETAS (Heating Equipment Testing and Approval Scheme) registered installer will ensure these safety rules are met on your behalf. The two major risks are carbon monoxide poisoning and fire damage. In all cases, follow the stove manufacturers’ instructions.

Basically, you have a choice of either:

• Hiring a HETAS installer registered with the Government’s Competent Person Scheme to self-certify their work complies with all the regulations. The installer will then register your stove as an installed appliance with HETAS which in turn notifies your local authority. The homeowner receives a Certificate of Compliance to show the stove has been fitted by a trained installer and meets the regulations.
• Submitting a notice to your local authority building control department so the work can be checked and signed-off. Anyone fitting a solid fuel stove must be competent to do so – that is familiar with the correct procedures and detailed regulatory requirements. A building control officer might insist a HETAS registered installer carry out testing and advice on its safety. You will be charged for this report.

Stoves for smoke control areas

Many towns and cities in the UK are smoke-controlled zones, meaning you will have to get a stove approved by Defra (Department for Environment, Food and Rural Affairs) to burn wood. Basically, the appliance has been altered so more air is provided in the combustion process, so it burns hotter with less emissions. In 2019, Government announced a ban on the most polluting of wood burners, set to become law in January 2022. Fortunately, some of these more environmentally friendly appliances are already on the market, labelled as ‘Ecodesign’.

‘ClearSkies’ certified stoves at Level 3 meet or go beyond the emissions and efficiency requirements of the Ecodesign scheme. Even if you don’t live in a smoke-controlled area, it’s a good idea to buy one of these stoves, so you’re assured it is less polluting. Alternatively, choose a multi-fuel stove for burning smokeless fuel.

Check the chimney

Before installing a stove, it’s essential to check the condition of the existing chimney. A chimney should contain a sealed flue from the appliance to the chimney pot to discharge smoke and gases from the combustion to the outside air. Over time, the condition of a chimney can deteriorate as tar and corrosive soot deposits erode mortar joints. 

It was only from 1965 that Building Regulations required all new chimneys to be built with flue liners. Older chimneys may have no flue lining and be in poor condition, meaning deadly gases could potentially leak through the chimney walls.

According to the British Flue & Chimney Manufacturers’ Association (BFCMA), the check should be carried out by a chimney specialist and include:

• Sweeping the chimney to make sure there are not any obstructions like a birds’ nest or dislodged masonry
• A smoke test to establish if the chimney is working properly or if there are any major faults that may cause smoke to leak through the chimney walls.
• Making sure the chimney is wind and watertight as well as structurally stable.

Re-lining chimneys

The chimney check should identify if any work is needed. Often the simplest way to refurbish a defective flue is to reline it.  While this isn’t a Building Regulations requirement as such, it is good practice and the industry norm.  For new-build chimneys, flue liners can be built from clay, concrete or pumice. A modern, cheaper alternative is to use stainless steel liners, either single wall rigid or flexible. It’s a good idea to ask a specialist stove installer to carry out any lining work rather than a general builder.

All stoves must be installed away from combustible materials, including timber fireplace surrounds, beams and plaster board walls. Minimum distances must be maintained to comply with Building Regulations and reduce fire risk. Beams over fireplaces may be a better option than wooden mantlepiece as they can be lifted high enough to maintain the minimum distance required.

Do you need a chimney for a stove?

Generally, yes. In most cases, a stove will fit inside your existing fireplace and have an attached stainless steel flexible flue liner which goes up the chimney. If no chimney is present, a new masonry one can be built, for example from bricks, liner and insulating concrete. Building Regulations outline the requirements, including height (minimum 4.5m).

A popular alternative is to choose an insulated factory-made twin wall metal flue pipe. The rigid flue system can be installed, either straight up and through the roof or out through the wall and up the side of the building.  

Smoke and gas particles from the chimney must be able to disperse freely into the atmosphere. So, the flue outlet must be positioned sufficiently high above the roof surface and away from windows. Building Regulations identify the zone required for this.

Air Vents

Stoves need a supply of air to burn efficiently and avoid the production of carbon monoxide, a highly toxic, odourless and colourless gas. The ventilation area is based on the rated output of the appliance and air permeability of your home. Because modern properties are now built more airtight for energy efficiency reasons, the ventilation required is increased to create an adequate draw for the chimney.

Some manufacturers now produce wood burners connected to an external air duct which makes sense in modern, well-sealed homes.  A professional HETAS installer can advise you on the air vents required to comply with Building Regulations.

Carbon monoxide alarms

All wood burners have the potential to cause carbon monoxide poisoning if wrongly installed or incorrectly used. Building Regulations require the installation of a BS EN 5091 kitemarked carbon monoxide alarm to be fitted with any new or replacement wood burner.

The positioning of the alarm is important to ensure compliance with the regulations. It should be placed within one to three metres of the appliance and either:

• On a wall as high up as possible but at least 150mm from the ceiling or
• On the ceiling at least 300mm from any wall.

This is to ensure they are not placed in any ‘dead air zones’ that occur in corners and spaces where the airflow may be blocked.

Building Regulations cover everything from the size of flue to the distance between the stove and combustible items and carbon monoxide detectors. Experts recommend having your stove installed by a HETAS-registered installer as they will give you a Certificate of Compliance.

Before buying a stove, it’s a good idea to commission an installation survey from a HETAS-approved retailer or installer. A key part of choosing the best stove is getting the correct size and heat input for your home. Factors such as the room’s airflow and insulation level must be considered as well as suitability of the chimney.

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