BS 7671 Amendment 4:2026 — what changed and what it means on site
Amendment 4 — the Orange Book — was published on 15 April 2026. The Brown Book stays valid until 15 October 2026, so you have a short window to get current before the changeover.
Updated 2026-09-22
The transition date that matters
BS 7671:2018+A4:2026 was published on 15 April 2026 and can be worked to immediately. Amendment 3:2024, the Brown Book, remains a valid standard until 15 October 2026, so during that window installers may design and certify to either edition.
Pick one edition per job and state it on the certificate. Mixing clauses from both books across a single installation is where disputes start.
Battery storage gets its own chapter
The headline change is a new chapter covering stationary secondary batteries used to store and supply an installation. It sets out requirements for system design, power conversion equipment, bidirectional and hybrid inverters, and whether your protective devices are actually suitable for two-way energy flow.
It also puts real weight on the physical side: where the battery is located, ventilation, and fire risk mitigation. If you have been treating a home battery as an accessory bolted onto a solar install, that approach no longer matches the standard.
- · Confirm protective devices are rated for bidirectional current
- · Assess battery location, ventilation and fire separation as part of the design
- · Treat vehicle-to-home and vehicle-to-grid setups as a storage system, not an EV accessory
Power over Ethernet and ICT functional earthing
A new section covers Power over Ethernet installations, which have quietly become a mainstream electrical load in offices, schools and care settings. There is also a new section on functional earthing and functional equipotential bonding for information and communication technology equipment.
If you install cabling for cameras, access control, lighting nodes or wireless access points, these sections are now part of your compliance scope rather than someone else's.
Medical locations rewritten
Section 710 on medical locations received a major revision, including a schedule of test results for recording the resistance of supplementary protective equipotential bonding conductors. Anyone working in dental practices, clinics or healthcare premises needs to read this section in full rather than rely on memory.
EICRs and the evidence you can attach
The revised model condition report moves Further Investigation to an advisory status, which means an installation can be recorded as satisfactory while still carrying FI observations. Expect this to be argued over on jobs for the next year, so be explicit in your notes about why you coded what you coded.
More usefully, reports can now carry photographic evidence and thermal imaging results. That is a straightforward win for proving condition to landlords, agents and insurers.
The small change that touches everything
Indented lists have moved from Roman numerals to letters to align with other British Standards. It sounds trivial, but every reference point shifts, so your training notes, method statements, checklists and office templates all need reviewing against the Orange Book.
What to do this month
Buy or subscribe to the Orange Book, book an Amendment 4 update, and log it as CPD with dates and hours. Scheme assessors will ask how you have kept current, and a dated record of an update course is the cleanest answer you can give them.