Is Balcony Solar Legal in the UK? Everything That Changed in April 2026
Updated: May 2026 · By Depth of Light Ltd, Milton Keynes
For years, balcony and plug-in solar sat in a UK regulatory grey area — technically possible, often DIY, rarely legally clean. BS 7671 Amendment 4, which came into force in April 2026, finally formalised the rules. Here's what's now allowed, what still isn't, and what changes again later in 2026.
The short answer
Yes — balcony and plug-in solar are now legal in the UK, with two important conditions during 2026:
- The system must be hardwired by a registered electrician — not plugged into a normal socket. This changes later in 2026 once DIY-grade plug-and-play kits are formally certified.
- The DNO must be notified under G98. The 800W output limit means most installs use the simpler G98 (rather than G99) process.
What BS 7671 Amendment 4 actually changed
The previous wiring regulations (BS 7671:2018 + Amendments 1-3) didn't have a clear category for small plug-in solar systems. They were neither explicitly allowed nor explicitly prohibited. In practice this meant insurers refused claims, councils raised eyebrows, and the safest interpretation was "don't".
Amendment 4 introduced a new section covering small-scale prosumer installations up to 800W. Key points:
- Up to 800W of solar output per property is permitted
- Hardwired connection to the consumer unit, with a dedicated MCB
- Microinverter or string inverter sized appropriately
- RCD/RCBO protection on the new circuit
- G98 DNO notification (within 28 days of energisation, handled by the installer)
- Must be installed by a registered electrician (NICEIC, NAPIT, ELECSA or equivalent) until DIY plug-and-play kits are formally certified
The Renters' Rights Act 2025 — your right to request
The Renters' Rights Act 2025 introduced a "right to request" clause that means landlords can no longer unreasonably refuse a tenant's request to install reversible energy efficiency measures, including balcony solar. Combined with the new BS 7671 framework, this is the first time UK renters have had a clear, legal route to install their own solar.
What changes after July 2026?
Later in 2026 the framework around DIY plug-and-play kits is expected to be finalised. At that point, certified plug-in kits (sold as complete units with their own G98 documentation) will be permitted in some scenarios — broadly, single-panel installs up to 400W into a domestic property with a SMETS2 smart meter.
That said, even after July 2026 there will still be reasons to use a hardwired professional install rather than DIY:
- MCS certification (DIY kits won't be MCS-eligible)
- Insurance — most home insurers require professional install
- 0% VAT (DIY kits sold direct to consumer don't qualify)
- Smart Export Guarantee (requires MCS — DIY doesn't qualify)
- Twin-panel 800W setup (DIY framework will be limited to 400W)
What it costs to install legally in 2026
- Single panel (~400W) hardwired install: from £800 fully installed, MCS certified
- Twin panel (~800W, max permitted): from £1,400 fully installed
- DIY kit (currently non-compliant): £400-£600 — but voids insurance, no MCS, no SEG eligibility
Bottom line
Balcony solar is finally legal — but the cheap DIY route most people picture isn't yet legal in the UK. Until the plug-and-play framework lands, the legal route is a hardwired install by a registered electrician. We do these across Milton Keynes and Buckinghamshire — see our balcony solar service page.
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