What is HETAS and when do you need it for a chimney?
Regulations & safety

What is HETAS and when do you need it for a chimney?

HETAS is the recognised scheme for solid-fuel and biomass work.

The short answer

HETAS is the official body recognised in the UK for solid fuel, wood and biomass heating, running a competent person scheme for installers and registers for sweeps and serviced products. You need a HETAS-registered installer when you carry out controlled work under Approved Document J on a solid-fuel system — chiefly installing or replacing a stove, relining or fitting a flue, or building a hearth — because a registered installer can self-certify and notify the work without a separate building control application and issue a certificate. You do not need HETAS for ordinary repointing, flashing or pot repairs, which are maintenance, nor for gas work, which must be done by a Gas Safe engineer instead.

HETAS sits alongside building control as the route to certify solid-fuel chimney and appliance work. Here is what it covers.

HETAS at a glance

What HETAS is

HETAS is the body recognised by government for the solid fuel, wood and biomass sector. It operates a competent person scheme under the Building Regulations, which means a HETAS-registered installer can certify their own work as compliant with Approved Document J and notify it to building control on your behalf. HETAS also maintains registers of approved chimney sweeps and lists approved appliances and fuels, and provides training and guidance. Using a HETAS-registered installer is not a legal requirement in itself, but it is the simplest way to make sure solid-fuel work is compliant and properly documented.

When you need a HETAS installer

You need a HETAS-registered installer — or a building control application — whenever you do controlled solid-fuel work. The common cases are installing or replacing a wood-burning or multi-fuel stove, relining the chimney or fitting a new flue, opening up and bringing a fireplace back into use, and constructing or altering a hearth. In each case the installation must meet Approved Document J on flue sizing, hearth construction, air supply and protection from heat. A registered installer handles the certification and gives you a certificate of compliance, which proves the work was notified.

WorkHETAS route applies?
Installing a wood-burning stoveYes — solid fuel, controlled work
Relining a flue for solid fuelYes — controlled work
Repointing the stackNo — maintenance
Renewing flashing or a potNo — maintenance
Fitting a gas fireNo — use Gas Safe instead

Indicative; HETAS covers solid fuel and biomass, not gas. Sources: HETAS; gov.uk Approved Document J.

HETAS sweeps and what it does not cover

Alongside installers, HETAS lists approved chimney sweeps who have met its training standards, which can help when you want a sweep's certificate for an insurer. It is worth being clear about the limits: HETAS is for solid fuel, wood and biomass, so gas appliances and flues are outside it and must be handled by a Gas Safe-registered engineer. Simple repair and maintenance — repointing, replacing a pot, renewing flashing or a cowl — is not controlled work and does not need a HETAS installer at all. Where the work is controlled, you always have the alternative of a building control application if your installer is not registered.

Check the register, not just the logo: before booking solid-fuel work, confirm the installer or sweep is actually listed on the HETAS register. That is what ensures the certificate they issue is genuine.

Frequently asked questions

Is it a legal requirement to use a HETAS installer?

No. The legal requirement is that controlled solid-fuel work complies with the Building Regulations. A HETAS-registered installer is the simplest way to meet that, but you can instead make a building control application.

Does HETAS cover gas fires and flues?

No. HETAS covers solid fuel, wood and biomass. Gas appliances and their flues must be installed and serviced by a Gas Safe-registered engineer, which is the equivalent scheme for gas work.

Do I need HETAS to have my chimney swept?

No. Anyone can sweep a chimney, but using a sweep listed by HETAS, the NACS or the Guild of Master Sweeps gives you a recognised certificate that insurers often prefer.

Sources & further reading

Figures on this page are typical UK ranges drawn from published sources and depend on your specific chimney. They are guidance, not a quotation.