Solar Panels

Is Balcony Solar Legal in the UK? Everything That Changed in April 2026

Updated: 21 September 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, which kits are actually certified, and where the rules still catch people out.

800WMax permitted output

£800+Hardwired install from

G98DNO notification only

0% VATUntil March 2027

The short answer

Yes — balcony and plug-in solar are now legal in the UK, with two important conditions during 2026:

The equipment must be on the ENA register to count as compliant. As of 27 August 2026 that means seven kits, all made by UKSOL.
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

Renting? Ask your landlord first

If you rent, whether you can fit balcony or plug-in solar comes down to your tenancy agreement and your landlord — that's between the two of you, and we can't tell you what it allows. A written specification and confirmation that the install is fully reversible makes it an easier yes for a lot of landlords, but always ask before fitting anything, including a plug-in kit on a socket.

ENA-certified kits since 27 August 2026

The certification framework landed sooner, and broader, than expected. ENA-certified plug-in solar kits have been on the register of compliant equipment since 27 August 2026. There are seven of them, and all seven are made by UKSOL Ltd. If a kit is not on that register, it is not compliant equipment, whatever the product listing claims.

Worth correcting an earlier expectation on this page: the framework was widely predicted to be capped at single-panel 400W installs. It was not. The registered kits run to twin-panel arrays of 1260W — though every one of them is limited to 800W of export, which is the number that actually matters. The panel figure is the array size, not what reaches your home.

Reasons to still use a professional install rather than fitting a kit yourself:

Your wiring is not covered by the kit's certification — see below
MCS certification (self-fitted kits aren't MCS-eligible)
Insurance — most home insurers require professional install
0% VAT (kits sold direct to consumer don't qualify)
Smart Export Guarantee (requires MCS)

Own your roof? A proper rooftop system earns more and qualifies for the Smart Export Guarantee.

Get a fixed-price solar quote

The register certifies the kit, not your house

This is the distinction that gets lost. A kit on the ENA register has been assessed as a product. Nobody has assessed the circuit you are about to back-feed 800W into.

Whether that circuit can take it depends on whether the socket circuit is RCD-protected, how heavily the ring final is already loaded, whether the board has surge protection, and whether the installation is TT earthed. A rewireable board, or one with a single 30mA RCD covering the whole installation, is the case worth looking at before you buy.

If your consumer unit dates from roughly 2016 onward, the answer is usually that it is fine and you need nothing further. If it is older, our guides to EICRs before solar and consumer unit upgrade costs cover what is involved.

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 self-install (non-compliant without a professional fit): £400-£600 — but voids insurance, no MCS, no SEG eligibility

Quick fact An 800W balcony system in Milton Keynes generates roughly 700-800 kWh per year. If you use most of it at home, that's £170-£200 saved annually. Payback: 6-9 years on a £1,400 install.

Bottom line

Balcony solar is legal, and ENA-certified kits now exist as products. But the cheap self-fit route most people picture still isn't a compliant installation — a certified kit gives you compliant equipment, not a compliant install. The legal route is a hardwired install by a registered electrician, with the G98 notification handled for you. We do these across Milton Keynes and Buckinghamshire — see our balcony solar service page, where we also cover when a full rooftop system is the better choice.

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Related guides

Cost, savings and whether it is worth it

Merged from our plug-in solar guide: what the kits cost, what they realistically save, who they suit, and when a roof system is the better answer.

How much do they cost?

The hardware for a typical 2-panel 800W system — two 400W panels plus a microinverter — costs around £500. Several brands are entering the UK market from Europe (where these products have been sold legally for years), and prices are likely to fall further once the BSI product standard is published and retail distribution scales up.

The compliant installation cost on top is roughly £200–£400 for a CPS-registered electrician to hardwire the system to a dedicated circuit at your consumer unit. The exact cost depends on how far the cable run is, whether any remedial work on the consumer unit is needed, and your location.

Cost item	Typical price
2 × 400W panels + microinverter (hardware)	£500
CPS electrician — hardwired install + G98 notification	£200–£400
Total (compliant installation)	£700–£900

Note that 0% VAT does not currently apply to plug-in solar systems in the same way it applies to full rooftop installations. VAT treatment for these small systems is still being clarified — check with the supplier before purchase.

How much do they save?

An 800W system in the UK generates roughly 650–800 kWh per year, depending on your location, the orientation of the panels, and how much shading affects them. Milton Keynes is reasonably well-placed in terms of UK solar irradiance.

At the current standing rate of 26.32p per kWh, that works out to approximately:

£160–£200 Saved per year at 26.32p/kWh

4–6 yr Payback period (compliant install)

800W Maximum system size (current rules)

The savings figure assumes you actually use the electricity the system generates rather than exporting it unmetered. If you are out during the day and the system is generating but you are drawing nothing, much of that generation will go to the grid without payment. This is one of the key limitations — covered below.

Who are plug-in solar panels for?

The honest answer is a fairly specific audience:

Renters who cannot make structural changes to the property and want some reduction in their electricity bill
Flat owners who have no roof access but have a south-facing balcony or garden space
People with no suitable roof — north-facing, heavily shaded, or structurally unsuitable roofs
People testing solar before committing to a full rooftop system — though this is a fairly expensive way to test it given the limited ROI
Lower-usage households where even £160–£200/year is meaningful in proportion to overall consumption

If you fall into one of those categories, plug-in solar is now a legitimate option in the UK. If you do not — if you own your home and have a reasonable roof — keep reading.

The limitations you need to know

Plug-in solar systems have some real constraints that the marketing tends to gloss over.

No battery integration

An 800W plug-in system cannot connect to a home battery. The power it generates is fed directly into your home circuit and consumed immediately or exported. You cannot store excess generation for evening use. This significantly limits how much of the output you actually benefit from — if you are at work during the day, the panels may be generating while your consumption is near zero.

No Smart Export Guarantee (SEG) payments

To receive SEG payments for exported electricity, you need a smart meter and a metered G98 connection. Most plug-in solar setups are not configured for export metering, so any surplus you generate and export goes to the grid without compensation. You are effectively giving it away.

Limited impact on high-usage households

If your household uses 4,000+ kWh per year (typical for a 3–4 bedroom house with multiple occupants), an 800W system generating 650–800 kWh covers roughly 15–20% of that consumption at best. The saving is real but modest. A full rooftop system sized properly for your household would cover 40–60% of consumption and then some.

Planning considerations

Panels on balconies, external walls, or free-standing frames in gardens may require planning permission — particularly on listed buildings, in conservation areas, or where the installation would be visible from a public highway. The permitted development limits changed on 27 August 2026; see what changes on 27 August 2026 for the current figures. Check with your local authority if you are unsure.

Tenancy restrictions

Even though you may be renting, a hardwired installation still requires landlord consent because it involves work on the consumer unit. Some landlords will agree; many will not. Now that registered kits are available, the socket route no longer requires work on the consumer unit — which removes the main reason a landlord would refuse. You will still need consent, and the property’s wiring still needs to be suitable.

When does a proper rooftop system make more sense?

For most homeowners with a suitable roof, the comparison is stark.

The numbers for Milton Keynes homeowners

For homeowners in Milton Keynes, a 5kWp rooftop system saves £800–£1,000 per year — versus £160–£200 from a plug-in system. Over 10 years, that difference is £6,000–£8,000. The maths almost always favour going full rooftop if you own your home and have a suitable roof.

Here is when a proper rooftop solar system is clearly the right choice:

You own your home. You can make the structural changes and you will benefit from the long-term return.
You use more than 3 kWh/day. At that level of consumption, a properly sized rooftop system makes a material difference to your bill. A plug-in system does not.
You want to charge an EV at home. You need a properly sized system to generate enough surplus to charge a car. An 800W plug-in will not make a meaningful contribution to EV charging.
You want battery storage. Battery storage connects to a rooftop system, not to a plug-in. If you want to store solar energy for evening use, you need a full installation.
You want backup power. Some battery systems can provide power during grid outages. That requires a full system — not a plug-in.
You want the best long-term ROI. A 5kWp rooftop system typically pays back in 6–8 years at current rates, then generates free electricity for 20+ years. A plug-in system returns a fraction of that value over the same period.

To understand what a rooftop system would cost and save for your specific property, use our free solar calculator. It gives you a realistic estimate based on your roof size, location, and energy usage — not a generic ballpark figure.

Is your home suited to rooftop solar?

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For context, here is how plug-in compares to a full rooftop system on the numbers that matter:

	Plug-in (800W)	Rooftop (5kWp)
Annual generation (MK, UK avg)	650–800 kWh	4,500–5,000 kWh
Annual saving (self-consumed)	£160–£200	£800–£1,000
Battery integration	No	Yes
EV charging contribution	Minimal	Significant
SEG export payments	Very unlikely	Yes (with smart meter)
Hardware + install cost	£700–£900	£7,000–£10,000
Payback period	4–6 years	6–9 years
Saving over 20 years	£3,200–£4,000	£16,000–£20,000+

The payback periods are comparable. The total return is not. That gap is even larger if you add a battery storage system or qualify for any grants and incentives.

Plug-in solar is a legitimate entry point for people who have no other option. For homeowners with a suitable roof, it is the expensive, low-return version of something you could do properly for 10–12 times the savings.