Amendment 4: What’s Changing for Electrical Installations in 2026?

A breakdown of the latest BS 7671 Amendment 4 changes and what they mean for electrical installations, compliance and future projects across homes and commercial buildings.

With Amendment 4 to BS 7671 now published and set to become mandatory from October 2026, Circle Electrical is already preparing for the changes that will shape electrical design, installation and compliance across the South West and Wales.

As a NAPIT and TrustMark registered contractor, staying ahead of regulatory updates is a core part of how we work, and Amendment 4 introduces some of the most significant changes in recent years.

What’s Changing?

Amendment 4 introduces updates across several key areas, including:

Battery Storage Systems

A full chapter now covers stationary secondary batteries, hybrid inverters and two-way energy flow, reflecting the continued growth of renewable technologies in homes and commercial buildings.

Power over Ethernet (PoE)

New guidance introduces clearer rules around cable ratings, voltage limits and installation standards for smart buildings, CCTV systems and modern lighting infrastructure.

Medical Locations

Updated safety requirements aim to improve protection for patients and staff in healthcare environments.

Functional Earthing & ICT Systems

Important changes affecting data centres, communication networks and technically complex commercial installations.

Parallel Generation

Further clarification for installations involving multiple energy sources, including solar and battery storage systems.

Fire Safety Improvements

More precise requirements around supporting wiring systems in the event of fire.

Changes to EICR Reporting

The FI (Further Investigation) code becomes advisory, meaning installations may still be marked satisfactory even where FI observations are present; a change likely to generate discussion across the industry.

How Circle Electrical Is Preparing

We’re already integrating Amendment 4 into our design and installation processes to ensure all new works align with the updated standards well ahead of the October 2026 deadline.

This includes:

Updated design templates and documentation

Revised testing and inspection procedures

Training across our in-house team and specialist subcontractors

Early adoption of requirements relating to battery storage, PoE and functional earthing

Clearer EICR reporting in line with revised model forms

Whether we’re working in homes, schools, hotels or industrial plantrooms, our aim remains the same: delivering installations that are safe, compliant and future-ready.

What Clients Should Know

If you’re planning electrical works in 2026 - particularly rewires, consumer unit upgrades, commercial refurbishments or renewable installations - Amendment 4 may affect your project.

We’re here to help guide clients through the changes, explain what applies to each installation, and ensure all works are completed to the latest standards.