BS 7671 is the core standard at the heart of UK electrical professionals’ working lives. But how much do you know about the process behind its creation and ongoing development?
Paul Collins | Technical Director
The Wiring Regulations have only been a British Standard since 1992, but BS 7671 has a lengthy and distinguished back story, stretching back to the first wiring rules and regulations published in 1882.
This long history shows how requirements for electrical work and installations have adapted as the sector has evolved. To keep up with new practices and technologies, the requirements are constantly being updated and refined.
The first edition of the Wiring Regulations, which was just four pages long and contained 21 regulations, focused on “the prevention of fire risks arising from electric lighting”.
Today, BS 7671 is more than 650 pages long and includes everything from information communications technology equipment to solar PV and electric vehicle charging installations.
International standardisation
International co-operation to develop common electrotechnical standards has been going on for more than a century, with the first council meeting of the International Electrotechnical Commission (IEC) held in London in 1908.
The UK was at the forefront of this movement and continues to play a central role in electrotechnical standards development worldwide.
At NICEIC, we often get asked why BS 7671 changes so often. And the simple answer is that the UK is a member of both the IEC, which is responsible for global standards, and the European Committee for Electrotechnical Standardization (CENELEC), which sets European standards.
Most of the changes included in BS 7671 start life at the IEC level, and progress to CENELEC, although sometimes the development work happens in parallel. The international standard is known as IEC 60364, while the European standard is CENELEC HD 60364.
BS 7671 includes a list of all the IEC and CENELEC standards (currently 41) that form the base documents for the various parts of BS 7671. These standards are subject to a maintenance cycle, and these cycles differ, which produces a constantly evolving landscape that BS 7671 has to reflect.
In the UK, we have all parts of the 60364 standard1 in a single cover, BS 7671. This makes it more user friendly and convenient, as well as cost-effective for purchasers.
Standards development framework
There are various committees responsible for electrotechnical standards. Globally, it is IEC Technical Committee 64 (IEC TC 64), which has 41 participating countries and 14 observer countries.
At the European level, there is the CENELEC Technical Committee 64 (CLC TC 64), with 34 member countries and 13 affiliates. Finally, in the UK the national committee is the Joint Power and Electrotechnical Committee (JPEL/64), which is run by the IET and British Standards Institution (BSI) and oversees the work of four further sub-committees.
There are several distinct stages in standards development. At the IEC or CENELEC level, these include issuing various drafts for comment, reviewing comments, then producing drafts for voting, followed by publication of the final standard. UK experts sit on both the IEC and CENELEC committees, and JPEL/64 reviews and submits comments, as well as voting on the standards.
Sometimes, individual countries can’t fully adopt IEC or CENELEC requirements. To deal with this, there are agreed processes to recognise differences. For example, at the IEC level, the national committee can request a “certain countries note”.
These notes apply in cases where there are particular permanent conditions, (such as a requirement conflicting with national legislation), or where there are long standing differing practices, such as use of the 13A plug in the UK.
CENELC also recognises country-specific needs through a ’deviation’ (a clash with national regulations) or a “special national condition” where there is a national characteristic or practice that cannot be changed. A good example of this is permanently frozen ground in northern countries, which would exclude certain earthing condition requirements.
Structure of a British Standard
Electrical installations in the UK have to meet the technical intent of CENELEC’s HD 60364, so the UK is bound to take on any technical amendments at a European level. This doesn’t mean following the standard to the letter, but it does means taking it on in the spirit it was intended.
British Standards have a specific status and structure, which partly explains why the process of updating BS 7671 is so intricate and time consuming.
Each British Standard follows a standard layout:
BS 7671 largely follows this structure, though it is slightly atypical in some places, mainly because of its history as the Wiring Regulations.
There are also strict rules around language use in the standard. Largely based on the “Rules for the structure and drafting of UK standards”, these conventions offer some insight into why it can take so long to get the wording right for new and updated requirements.
When writing a standard, one of the rules is that for a requirement you always use ‘shall’ or ‘shall not’, whereas for a recommendation, it must be ‘should’ or ‘should not’.
Other conventions include that people ‘comply’ with a standard, while things ‘conform’ to a standard. The word ‘must’ cannot be used, and ‘will’ should be avoided.
You also have to be careful how you phrase a requirement. It must be achievable, and it must also ensure it doesn’t undermine itself.
Making changes
Changes to BS 7671 can be made through amendments, corrigenda, or the publication of new editions.
With the recent publication of Amendment 3:2024 of BS 7671 and the consultation on Amendment 4:2026 on all our minds, it’s useful to clarify what amendments involve.
An amendment alters or adds significantly to previously agreed technical provisions in an existing standard. Generally, the more changes required the less likely they are to be in an amendment and the more likely in a new edition.
No matter how many there are, amendments retain the original publication date, with an amendment date added. Only new or changed text is edited and issued for public comment. Additions, changes and deletions are marked with amendment tags.
People often ask whether there is a limit on the number of amendments a standard can have. At the IEC level, there can only be two amendments while, at CENELEC, there can be up to three. The answer is less clear cut for BS 7671, but it’s unlikely we’d see more than four.
Corrigenda, of which there are two to the current edition, are different to amendments. They are published to rectify errors inadvertently introduced during drafting or production of a standard that could lead to incorrect or unsafe application. Trivial errors are usually left uncorrected until the need for more substantial amendment arises
New editions are issued where many changes are introduced that affect a large proportion of the content, making an amendment unsuitable. Only new or changed text is edited and available for public comment, and each new edition takes a new publication date.
Commenting on drafts
Drafts incorporating proposed changes to British Standards are made available for public comment. And there is a similar process for IEC and CENELEC standards.
In the case of a British Standard, BSI publishes a draft for public consultation (DPC) and makes it available for comment by anyone. The length of the consultation period can vary but is made clear at the launch.
All comments are compiled and directed to the relevant JPEL/64 sub-committee for consideration. Only comments providing a rationale and proposal will be considered.
If you just put in a comment moaning about what you don’t like, and you don’t put in a reasoned proposal, it will simply be noted, and the committee will move on to the next one.
Anyone can also comment on IEC and CENELEC drafts. Bear in mind that when you’re commenting on BS 7671 proposals, such as Amendment 4, you’re commenting on something on which the UK has to adopt the technical intent. If you get involved at IEC stage, then you’re going one step back and shaping the technical intent.
A unique standard
BS 7671 is a unique standard with a long history. It has to reflect its many changing constituent parts, as well as constant advances in technology and practice.
As the industry evolves, we have to keep pace with what electricians have to do on a daily basis in the real world. This is why understanding the rigorous and collaborative process behind maintaining and updating BS 7671 is so important.
Learn more about the history of the Wiring Regulations.
Check out THE WIRE on-demand, where a recent episode focused on uncovering the process behind the BS 7671. This includes insights from Michael Peace, Senior Engineer for Technical Regulations at the IET.
Access the BSI portal to comment on Amendment 4.
Read our blog on Amendment 4.
This long history shows how requirements for electrical work and installations have adapted as the sector has evolved. To keep up with new practices and technologies, the requirements are constantly being updated and refined.
The first edition of the Wiring Regulations, which was just four pages long and contained 21 regulations, focused on “the prevention of fire risks arising from electric lighting”.
Today, BS 7671 is more than 650 pages long and includes everything from information communications technology equipment to solar PV and electric vehicle charging installations.
International standardisation
International co-operation to develop common electrotechnical standards has been going on for more than a century, with the first council meeting of the International Electrotechnical Commission (IEC) held in London in 1908.
The UK was at the forefront of this movement and continues to play a central role in electrotechnical standards development worldwide.
At NICEIC, we often get asked why BS 7671 changes so often. And the simple answer is that the UK is a member of both the IEC, which is responsible for global standards, and the European Committee for Electrotechnical Standardization (CENELEC), which sets European standards.
Most of the changes included in BS 7671 start life at the IEC level, and progress to CENELEC, although sometimes the development work happens in parallel. The international standard is known as IEC 60364, while the European standard is CENELEC HD 60364.
BS 7671 includes a list of all the IEC and CENELEC standards (currently 41) that form the base documents for the various parts of BS 7671. These standards are subject to a maintenance cycle, and these cycles differ, which produces a constantly evolving landscape that BS 7671 has to reflect.
In the UK, we have all parts of the 60364 standard1 in a single cover, BS 7671. This makes it more user friendly and convenient, as well as cost-effective for purchasers.
Standards development framework
There are various committees responsible for electrotechnical standards. Globally, it is IEC Technical Committee 64 (IEC TC 64), which has 41 participating countries and 14 observer countries.
At the European level, there is the CENELEC Technical Committee 64 (CLC TC 64), with 34 member countries and 13 affiliates. Finally, in the UK the national committee is the Joint Power and Electrotechnical Committee (JPEL/64), which is run by the IET and British Standards Institution (BSI) and oversees the work of four further sub-committees.
There are several distinct stages in standards development. At the IEC or CENELEC level, these include issuing various drafts for comment, reviewing comments, then producing drafts for voting, followed by publication of the final standard. UK experts sit on both the IEC and CENELEC committees, and JPEL/64 reviews and submits comments, as well as voting on the standards.
Sometimes, individual countries can’t fully adopt IEC or CENELEC requirements. To deal with this, there are agreed processes to recognise differences. For example, at the IEC level, the national committee can request a “certain countries note”.
These notes apply in cases where there are particular permanent conditions, (such as a requirement conflicting with national legislation), or where there are long standing differing practices, such as use of the 13A plug in the UK.
CENELC also recognises country-specific needs through a ’deviation’ (a clash with national regulations) or a “special national condition” where there is a national characteristic or practice that cannot be changed. A good example of this is permanently frozen ground in northern countries, which would exclude certain earthing condition requirements.
Structure of a British Standard
Electrical installations in the UK have to meet the technical intent of CENELEC’s HD 60364, so the UK is bound to take on any technical amendments at a European level. This doesn’t mean following the standard to the letter, but it does means taking it on in the spirit it was intended.
British Standards have a specific status and structure, which partly explains why the process of updating BS 7671 is so intricate and time consuming.
Each British Standard follows a standard layout:
- Foreword
- Introduction
- Scope
- Normative references
- Terms and definitions
- Main text
- Annexes – informative or normative (Optional)
BS 7671 largely follows this structure, though it is slightly atypical in some places, mainly because of its history as the Wiring Regulations.
There are also strict rules around language use in the standard. Largely based on the “Rules for the structure and drafting of UK standards”, these conventions offer some insight into why it can take so long to get the wording right for new and updated requirements.
When writing a standard, one of the rules is that for a requirement you always use ‘shall’ or ‘shall not’, whereas for a recommendation, it must be ‘should’ or ‘should not’.
Other conventions include that people ‘comply’ with a standard, while things ‘conform’ to a standard. The word ‘must’ cannot be used, and ‘will’ should be avoided.
You also have to be careful how you phrase a requirement. It must be achievable, and it must also ensure it doesn’t undermine itself.
Making changes
Changes to BS 7671 can be made through amendments, corrigenda, or the publication of new editions.
With the recent publication of Amendment 3:2024 of BS 7671 and the consultation on Amendment 4:2026 on all our minds, it’s useful to clarify what amendments involve.
An amendment alters or adds significantly to previously agreed technical provisions in an existing standard. Generally, the more changes required the less likely they are to be in an amendment and the more likely in a new edition.
No matter how many there are, amendments retain the original publication date, with an amendment date added. Only new or changed text is edited and issued for public comment. Additions, changes and deletions are marked with amendment tags.
People often ask whether there is a limit on the number of amendments a standard can have. At the IEC level, there can only be two amendments while, at CENELEC, there can be up to three. The answer is less clear cut for BS 7671, but it’s unlikely we’d see more than four.
Corrigenda, of which there are two to the current edition, are different to amendments. They are published to rectify errors inadvertently introduced during drafting or production of a standard that could lead to incorrect or unsafe application. Trivial errors are usually left uncorrected until the need for more substantial amendment arises
New editions are issued where many changes are introduced that affect a large proportion of the content, making an amendment unsuitable. Only new or changed text is edited and available for public comment, and each new edition takes a new publication date.
Commenting on drafts
Drafts incorporating proposed changes to British Standards are made available for public comment. And there is a similar process for IEC and CENELEC standards.
In the case of a British Standard, BSI publishes a draft for public consultation (DPC) and makes it available for comment by anyone. The length of the consultation period can vary but is made clear at the launch.
All comments are compiled and directed to the relevant JPEL/64 sub-committee for consideration. Only comments providing a rationale and proposal will be considered.
If you just put in a comment moaning about what you don’t like, and you don’t put in a reasoned proposal, it will simply be noted, and the committee will move on to the next one.
Anyone can also comment on IEC and CENELEC drafts. Bear in mind that when you’re commenting on BS 7671 proposals, such as Amendment 4, you’re commenting on something on which the UK has to adopt the technical intent. If you get involved at IEC stage, then you’re going one step back and shaping the technical intent.
A unique standard
BS 7671 is a unique standard with a long history. It has to reflect its many changing constituent parts, as well as constant advances in technology and practice.
As the industry evolves, we have to keep pace with what electricians have to do on a daily basis in the real world. This is why understanding the rigorous and collaborative process behind maintaining and updating BS 7671 is so important.
Learn more about the history of the Wiring Regulations.
Check out THE WIRE on-demand, where a recent episode focused on uncovering the process behind the BS 7671. This includes insights from Michael Peace, Senior Engineer for Technical Regulations at the IET.
Access the BSI portal to comment on Amendment 4.
Read our blog on Amendment 4.
