BS8303 standard update

BS8303 standard update

In the latest HETAS Technical Bulletin we updated our registrants on the imminent changes to BS8303. In this article we highlight some of the key changes to the standard that will impact upon registered installers.

Over recent years, the industry through the UK BSI standards committee RHE/28 have been working hard in reviewing and updating the requirements contained in the solid fuel recognised standard BS 8303: 1994 Installation of domestics heating and cooking appliances burning solid mineral fuels. With the new standard due for publication and release in the coming days, it is important for registered installers and other industry personnel to be aware of the relevant changes, which include more up-to-date installation practices that better reflect the products and materials available on today’s market.

HETAS will continue to publish ongoing information to its registrants on the new alternative approaches contained within the BS 8303 standard through its technical bulletin publications, as well as an update to the current HETAS H003 and H003 refresher training courses to include the relevant requirements.

Application of the Standard

HETAS continue to receive queries relating to the appropriate application of any provisions contained within recognised BSI standards, and how they can be applied with continued re-assurance in meeting the UK Building Regulation requirements. For solid fuel installations, page 40 of Approved Document J gives clear guidance on this issue by means of stating the following;

Alternative Approach

The requirements may also be met by adopting the relevant recommendation in the publications listed below to achieve a level of performance equivalent to that obtained by following the guidance in this Approved Document:

  1. BS EN 15287-1 Design, Installation & Commissioning of chimneys for non-room-sealed heating appliances
  2. BS 8303 Installation of domestic heating and cooking appliances burning solid mineral fuels

The important part of this statement is the word “equivalence”, which ensures that by way of adopting the approaches given in these two recognised standards that the installation is no less safe than what would occur by following the technical guidelines given within the Approved Document.

So what will change?

With the original standards last publication coming in 1994, the new standard will look more closely at covering the basic requirements surrounding more highly efficient closed appliances, and base less emphasis on new installation of inefficient opened fire appliances (covered in more detail in BS 1251:2015). This will include provisions for the hearth, recess construction, closure/register plate, air supply and maintenance.

There are two principle additions to the upcoming standard amongst the other covered that were not previously contained within the 1994 version, mainly constituting requirements for

  • The appropriate heat shielding of a freestanding appliance (not situated in a builder’s recess) up to 7kW nominal output in scenarios of lightweight timber construction properties
  • Information on the design, installation and assessment procedures relating to the installation of dedicated external air supply appliances.

The annex will also include updated commissioning guidance relating to the methods for commissioning flues and installations of varying types, using the industry recognised smoke and spillage test procedures.

Shielding of Combustibles

The standard will contain caveats for the appropriate protection of combustible materials when using a shield in a freestanding configuration, and state the required clearance and air gaps distances. In particular;

  • Use of a 1.5mm galvanized steel metal shield, affixed with non-combustible fixings to maintain an air gap of 25mm between the shield and the wall
  • Shield protrudes at least 300mm above the top surface of the appliance and extend to the edge of the hearth horizontally
  • The shield shall be open top and bottom to allow the flow of cool air between the shield and the wall
  • Distance from the appliance rear to the outer surface of the shield of at least 95mm and at least 90mm from the side of the appliance to the outer surface of the shield (if near to an adjacent wall)

Dedicated External Air Supply

The annex to the new BS 8303 will contain information to the appropriate design, assessment and commissioning of appliances with a dedicated external air supply, in line with HETAS technical guidance document HETAS_TN_0020. These include;

  • Ensuring installation of a dedicated external air supply kit is completed in line with manufacturer’s instructions, including consideration for the duct diameter, total length, air inlet terminal position and duct material specification
  • Appropriate risk assessment and commissioning procedures are undertaken to understand the properties current ventilation and air tightness, appliance roomsealed properties and again ensuring manufacturer instructions are available and met.
  • Appropriate smoke tests are completed, including with any extract running, and spillage test when the door is opened for refuel.

Further details and assessment/commissioning forms are available within the current version of HETAS_TN_0020, which is available on the technical area of the HETAS website at

If you have a technical question you can contact the team on 01684 278194 or email


Technical Q&A

Technical Q and A

CAT InviteIn association with The Centre for Alternative Technology (CAT), HETAS will be holding an installer technical question and answer session on the 16th August.

The technical Q and A session will take place on Thursday 16th August from 4:30pm to 7pm and will provide you with the opportunity to pose your burning questions to HETAS Training and Technical Manager Mike Harvey. From the new HETAS Unsafe Situations Procedure, misleading headlines on banning stoves through to your technical installation questions, Mike will be able to answer your questions.

The event is free to attend and there is no need to book in advance. For further details contact the CAT team directly on 01654 704963.

The event will also provide you with an opportunity to view the facilities available at this unique location.


Based in beautiful Mid Wales, the Centre overlooks the Snowdonia National Park, renowned for its stunning scenery and outdoor activities.

CAT is an education and visitor centre demonstrating practical solutions for sustainability. We cover all aspects of green living: environmental building, eco-sanitation, woodland management, renewable energy, energy efficiency and organic growing.  The site is a unique and valuable practical demonstration centre, a living laboratory with an enormous range of live examples of sustainable solutions. CAT has the largest range of installed renewable systems anywhere. These include:

  • Photovoltaics
  • Solar thermal
  • A micro-grid
  • Off-grid and grid-connected systems
  • Biomass combined heat and power (CHP)
  • Hydro
  • Air source heat pumps
  • A community heat main
  • A range of small to medium wind turbines
  • They also have two reed bed systems, our own off-mains water supply, and extensive organic gardens.

Click here to visit the CAT website.

Installation Sub Committee

Installation Sub Committee Formation

Installation Sub CommitteeThe HETAS Installation Sub-Committee (HISC) has been formulated as a mirror group to the HETAS Technical Committee (HTC), to allow for the discussion, evaluation and progression of installation specific technical issues, challenges and projects, and to help form resolutions, as well as increase communication and support between HETAS and its registered installers, retailers, maintenance engineers and chimney sweeps.

The HISC aims and objectives are to always promote the safe design, installation and use of solid fuel and biomass appliances through;

  • Discussion and development of resolutions to common installation issues experienced through industry stakeholder activity and allow HETAS to best target its resources
  • Undertake a more focused discussion on installation specific activities and develop better means to allow industry to carry out installation works safely and competently.
  • Continue to update members on current and any future changes to legislations which may impact industry and ensure members’ voice is heard.
  • Use meeting outcomes to influence future standards, consultations and regulation development, ensuring installers can carry out works in both a safe and realistic matter with today’s most up-to-date and verified installation methods
  • Feed meeting discussions into the wider HTC format amongst Appliance & Chimney Manufacturers, Test Houses and Fuel Producers
  • Use meeting to drive consumer awareness and education so that one standardised position is relayed and attainable

The group encompasses input from a wide variety of industry expertise from its stakeholder base, ensuring an open forum of discussion can be had, to continually promote industry activity and to support HETAS in providing effective guidance and clarification back to its stakeholders undertaking solid fuel installation works.

HETAS is always looking to continually work with, and better engage with its membership to promote effective change of the industry and its practices, and the HISC forms an integral part of this pushing for better quality standards and regulations, as well as being seen to be offering a more secure and safe route to meeting current and future Building Regulation compliance for its membership.

Sune Nightingale of Firepower Heating, who attended the first meeting comments: “It was a really productive first meeting. For me the most important thing was that we clearly saw that we needed to connect better with you, the installers on the ground. After all you are the ones who have to use the guidance which HETAS and the Technical Committee (the HTC) come up, you are the ones who see new issues as they crop up first, you are the ones that know whether a system is workable or not. We also thought it would be a good opportunity for you to get to know the people who make up HETAS and the things that they do.

“As far as I am concerned I take part in these committees to try to improve safety and at the same time keep things practical and doable. The other members are experts in their fields and so it is a pleasure and an honour to be part of them. Did you know that the members donate their time? We do get lunch and coffee.

“Over the coming months you should see HETAS start the ongoing conversation with you to invite feedback and suggestions. I will also be reaching out to the installers and engineers that we work with. It will of course take time, but I hope that you start to notice a difference in the general approach. Our industry is changing fast and faces new challenges: tightened legislation, new standards, EcoDesign, we have work to do to improve on emissions and we have to keep pace with new building methods. It’s a time where we very much need to be working together.”

Follow the HETAS newsletters for further updates from HETAS and the Installation Sub-Committee. Head over to the HETAS Technical Area to view all of our newsletters and Bulletins.

Working with Building Control

Working with Building Control (Appendix A) as part of Approved Document J

A recent roundtable hosted by HETAS revealed a number of issues that are affecting both the biomass and wood-burning stoves markets. One of the key areas of discussion was the issues surrounding the ‘signing off’ or ‘notification’ of solid fuel & biomass installations and the evident confusion over a HETAS installer’s role in assisting Building Control to sign off a job as being compliant to Building Regulations.

When looking to buy a home or secure buildings insurance for example, it is important to note that that existing installations must have been notified to Local Authority Building Control by the homeowner or by the builder/ installer concerned.  This notification, or lack of to some degree, is being recognised as an area of concern which needs legislation and enforcing. The subject was discussed recently at a Government meeting. Those present including the Technical Director of Local Authority Building Control (LABC) and the relevant person from the Ministry of House, Communities and Local Government. As this is a matter that effects all areas where self-certification is an option, MHCLG subsequently wrote to the CEO’s of all Local Authorities.

Mike Harvey, Training and Technical Manager at HETAS says, “If an installer is a registrant of a competent person self-certification scheme like HETAS, and the work undertaken is within their categories of competence, then they will notify through their scheme. However if the work undertaken by the installer is not within their recorded competence at the scheme, they cannot notify through their scheme. The only option is to go through Building Control at the local authority or in some cases via an approved inspector.”

HETAS acknowledges the wide range of skills that Building Control Officers have and the necessity for their continuous professional development. An increasing number of Local Authorities have taken the view that solid fuel and biomass training covering requirements within Approved Document J, its interaction with Approved Document F, other Approved Documents and associated Standards would be needed; upon taking this into consideration they have decided that this area of work would be best dealt with by people with specialist training and equipment.

Mike says, “Where a Building Control Officer is unsure about the safety or compliance of a job, he/she might ask for supporting information from a HETAS registered installer. It is likely that the registered installer would say that they cannot sign off the work of another person. In cases such as these the installer would not be ‘signing off an installation’.

“There is a caution in that neither a HETAS Registrant nor a Building Control Officer can definitively appraise some areas of the work undertaken e.g. around the outside of the chimney liner or in places where there is no real access. Consequently the Building Control Officer would be asking the HETAS Registrant for their best endeavours, ensuring appropriate testing where practical so that he/she can advise the Building Control Officer.

“The HETAS installer would be simply checking as much as they reasonably can maybe visually, plus perhaps flue draft, smoke test or whatever is appropriate and advising the Building Control Officer of their findings.”

“It is then for the Building Control Officer to make a decision based on their own skills and experience, plus the supplementary information supplied by the installer.”

“This combination of skills and checks is considered to be a robust way to address the situation.”

Mike adds, “HETAS has not been involved in discussion about who bears the cost of such an inspection but it seems reasonable that the person having the work done might be responsible.  Things are of course much clearer and simpler when a HETAS registrant undertakes the work and self-certificates to HETAS.”

“Should a Building Control Officer ask for assistance from a HETAS qualified installer to carry out an inspection to ascertain compliance they should use the form stated in Appendix A on page 70 of Approved Document J,  because, ultimately the BCO is signing the job off and not the HETAS installer.”

“Indeed, not all of our registrants will remember that HETAS have an agreement with Local Authority Building Control permitting them to assist a Building Control Officer. Anyone seeking clarity or experiencing difficulties engaging help and support should contact HETAS technical helpline.”

“Installers are aware that whilst the space to fit an appliance is often limited – determined by the shape of the room or location of the chimney breast – there are other factors that must be considered to ensure that the appliance adheres to Part J of Building Regulations.”

“This section of Building Regulations, which outlines requirements for combustion appliances and fuel storage systems, is often referenced during our helpline conversations. For example, questions around the use of Chimneys and flues relate to the requirements for discharge of products of combustion (J2) and protection of building (J4). These regulations and other relevant guidance including manufacturer’s instructions serve to ensure that products are installed compliantly, assuring end users in the use of the installation”.

“It’s great to see our installers are paying such close attention to these requirements and  taking them seriously by phoning for advice if the requirements are not clear for them,” says Mike.

HETAS is proud to have the support from various sectors and organisations in the industry. Working alongside influential organisations such as BFCMASFA and the SIA allows the technical team to provide the most up-to-date information and educated advice.

“Ultimately our aim is to be recognised as the go-to resource for any domestic heating related queries so that we can continue to encourage the improvement of products and promote high standards of quality, design, safety and efficiency.”

Contact the HETAS Technical Helpline to discuss this further, or call 01684 278194.