Additions and alterations

The Minor Works Certificate is intended to be used for additions and alterations to an installation that do not extend to the provision of a new circuit. Examples include the addition of socket-outlets or lighting points to an existing circuit, the relocation of a light switch etc.

It may also be used for the replacement of equipment such as accessories, motors or luminaires, but not for the replacement of distribution boards or similar items. Appropriate inspection and testing, however, should always be carried out irrespective of the extent of the work undertaken.

Every addition or alteration to an existing installation must comply with the current edition of BS 7671 and must not impair the safety of the existing installation and the relevant inspection and testing requirements of Chapter 64 also apply to additions and alterations. This applies especially to the replacement of a distribution board or consumer unit. In order to verify that the addition or alteration to an electrical installation complies with BS 7671, the relevant parts of an existing installation must be inspected and tested to confirm the safety of the addition or alteration, including for example:

  1. (a) circuit ratings;
  2. (b) circuit conductor sizes;
  3. (c) means of earthing;
  4. (d) protective conductor continuity; and
  5. (e) earth fault loop impedance.

Whilst there is no obligation to inspect and test any part of the existing installation that does not affect and is not affected by the addition or alteration, any departures or non-compliances observed are required to be noted in the ‘Comments on existing installation’ section of an electrical installation certificates (single-signature or multiple-signature) or minor electrical installation works certificates.

  • Course Content
  • Aim
  • Participants
  • Certification

Course Content

Introduction to BS7671:2018
Practical Activities – Testing & Guidance Note 3
Earthing Systems
Practical Activity and completion of Minor Works Certificate
Fault Protection
Earth Fault Loop Impedance Principles
Preliminary Inspect
Post Work Inspect
Minor Works Certificate completion


To ensure candidates understand and carry out Minor Works Correctly.

All Delegates Should:

  • Understand the BS7671 17th Edition:2015 Minor Works requirements

·        Understand the Principles of Minor Works Essential Inspection & Testing

·        Be able to carry out Preliminary & After Work Testing

·        Be able to complete Minor Works Certificates

·        Be able to confirm compliance of essential test values in BS7671

Most Delegates would:

·        Understand the different earthing systems in use and how to recognise them

·        Understand the means of Basic & Fault protection

·        Understand the earth fault loop path

Some Delegates could:

Understand full electrical installation inspection & testing


This course is for individuals or  employees with a requirement for legally compliant alterations to electrical installations.

This course will demonstrate for minor works a level of Competence and understanding to perform minor works.

There are no formal entry requirements to attend as it will refresh a practicing electrician’s knowledge and understanding of the requirements of BS 7671:2018 for Minor Works.


Candidates who successfully complete the City & Guilds Accredited written and practical assessment will receive a certificate of competence.

Call us to discuss your query

01782 756463

City & Guilds BS 7671 Minor Works Documentation Course

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£225.00Class Room Booking