DIY Solar Panel Installation UK: What You're Allowed to Do Yourself

There's no law against fitting your own solar panels in the UK. What trips people up isn't the mounting and wiring of the panels themselves — it's everything downstream of them: the electrical connection into your consumer unit, the paperwork your Distribution Network Operator (DNO) requires before you can legally export, and the certification that unlocks the Smart Export Guarantee (SEG) and 0% VAT. This guide separates what you're genuinely free to do yourself from what needs a qualified electrician, and what a DIY install costs you in incentives you'd otherwise get for free.

What you can legally do yourself

The physical, non-electrical parts of a solar install carry no special certification requirement for a competent DIYer:

• Mounting the rails and panels on a pitched or flat roof, provided the work meets Building Regulations Part A (structural) — the roof needs to be sound enough to take the additional load, which is why professional installers commission a structural check on older or unusual roofs.
• Running the DC cabling from the panels down to where the inverter will sit, using appropriately rated solar cable and connectors — though how the panels are strung together (see our series vs parallel wiring guide) is a design decision for the installer, not one to change mid-install.
• Siting and fixing the inverter itself, before it's live.
• Off-grid setups that never connect to the house wiring or the grid at all — for example, a shed or outbuilding running purely off a battery and its own DC circuit, as covered in our solar panels on a shed guide. These sidestep almost every rule in this article because there's no grid connection to notify or certify.

Where it stops being straightforward is the moment AC output from the inverter needs to be connected into your home's fixed wiring — the new circuit back to the consumer unit.

The electrical work that needs a qualified person

Connecting a solar inverter to your consumer unit is notifiable work under Part P of the Building Regulations (Approved Document P, in force since April 2013), because it involves a new circuit on the fixed electrical installation. In England and Wales, that leaves two routes:

1. Have the work done — or at least signed off — by an electrician registered with a competent person scheme (NICEIC, ELECSA, NAPIT and similar), who self-certifies the work and notifies building control on your behalf, typically within 30 days of completion.
2. Do the work yourself and notify your local authority building control directly, who will inspect it and charge a fee — commonly in the £150–£400 range depending on the council, on top of any correction work they require.

Technically, a confident DIYer can take the second route. In practice, almost nobody does, because the inspection fee narrows the saving versus hiring an electrician for that one connection, and getting it wrong on a live AC circuit is a genuine safety risk, not just a compliance one. Our Part P and Part A building regulations guide covers both halves — structural and electrical — in more depth.

DNO notification: the step every self-installer still owes

Regardless of who does the electrical work, any grid-connected solar installation has to be notified to your Distribution Network Operator under Engineering Recommendation G98 (systems up to 16A per phase, roughly 3.68kW single-phase — covers the vast majority of domestic installs) or the more involved G99 process for larger systems, which requires prior approval before connection rather than after. G98 notification happens after installation, within 28 days of commissioning, and the DNO cannot refuse a compliant G98 notification — it's a record-keeping step, not a permission gate. Our DNO application guide walks through the G98 vs G99 form and timeline in full. Skipping this step is illegal even if every other part of your install is faultless.

What a DIY install costs you: SEG and 0% VAT

The two financial incentives that make grid-tied solar pay back faster both require MCS (Microgeneration Certification Scheme) certification — and MCS certification is not available for a fully self-installed system, because MCS is an accreditation held by the installer, not the homeowner:

• Smart Export Guarantee (SEG) payments require an MCS-certified installation using MCS-certified products, confirmed by your MCS certificate. Without it, you can still generate and self-consume solar power, but you can't get paid for what you export. Some suppliers, including Octopus, will accept a non-MCS install with independent electrical and building-control certificates for a fee (commonly cited around £250), but this isn't standard across the market — check directly with your chosen supplier before assuming it applies.
• 0% VAT on solar installations, in place until 31 March 2027 under HMRC Notice 708/6, applies to the combined supply-and-install of qualifying energy-saving materials. If you buy the panels and inverter yourself and a merchant simply supplies them — materials only, no installation — that purchase is standard-rated at 20%. The zero rate only survives if a contractor supplies and fits the system as one package; DIY buyers lose it entirely on the hardware.

Between the two, a DIY install that skips certification can easily cost more over its lifetime than it saves on labour, once lost export income and the 20% VAT difference are added up — worth running the numbers against our full installation advice guide before committing either way.

The safety case for not doing it all yourself

Roof work is genuinely dangerous, and it's the part of a DIY solar install most likely to go wrong in a way that can't be undone. HSE's 2025/26 fatal injury statistics record 31 UK worker deaths from falls from height in the year — around a quarter of all workplace deaths — with falls from height responsible for roughly half of all construction-industry fatalities over the preceding five years. Professional installers use roof anchors, edge protection and — where a roof includes fragile rooflights or ageing coverings — specific fall-prevention measures that a one-off DIYer is unlikely to have access to or experience using. This is separate from the electrical risk of getting the AC connection wrong on a live circuit, and it's the reason most people who do go the DIY route stop at roof-mounting and cabling, and bring in an electrician for the final connection.

A middle ground: plug-in solar

If the goal is a lower-effort, lower-risk way to self-install, plug-in (balcony) solar is a genuinely different category rather than a scaled-down version of DIY roof solar. Legal in Great Britain from 27 August 2026 under BS 7671 Amendment 4, plug-in kits are capped at 800W, connect via a standard plug into an existing socket circuit rather than a new one, and still require G98 DNO notification but skip Part P entirely because there's no new fixed circuit involved. See our plug-in and balcony solar guide for the full rules, pricing and what it can realistically save.

Bottom line

DIY solar in the UK isn't illegal, but it's rarely the money-saving shortcut it looks like on paper once you account for the electrician you'll still need for the grid connection, the building-control fee if you skip one, and the SEG and VAT incentives a non-MCS install forfeits. Mounting panels and running DC cable yourself is a reasonable way to trim labour costs; treating the whole install — including the live AC connection — as a weekend DIY project is where the risk and the lost incentives start to outweigh the saving. If you're going ahead with the parts you can legally do yourself, our DIY solar installation hub walks through sizing your system, picking every component, and building a shopping list.