DIY solar panels in the UK: what you can and can't do

Solar kit has never been cheaper, YouTube makes it look straightforward, and if you're handy it's tempting to buy a pallet of panels and do it yourself. You can - there's no law against fitting your own solar. But before you order anything, it's worth knowing exactly which parts you're allowed to do, which parts need a registered professional, and what a DIY install quietly costs you in payments and protections. Here's the honest version.

What you're allowed to do yourself

Mounting rails and panels on your own roof is not notifiable work. Neither is running the DC cabling from the array down to where the inverter will go. Plenty of people do the mechanical side themselves - scaffolding, roof anchors, rails, clamping the panels in - and bring in an electrician only for the connection.

The catch is the roof itself. Working at height is the single biggest cause of serious injury in home improvement. A proper scaffold or tower, edge protection and someone else on site aren't optional, and a slipped tile or a cracked batten you don't notice becomes a leak six months later. If you don't already own the access equipment and the confidence to use it, that alone can wipe out the saving.

What needs a registered electrician

Connecting a solar system to your consumer unit is notifiable work under Part P of the building regulations. It has to be either done by, or inspected and certified by, someone registered with a competent-person scheme such as NAPIT, and notified to Building Control. Wiring an inverter into your board without that isn't just risky - it can invalidate your home insurance and cause problems when you sell.

There's a second sign-off most DIY guides skip: the DNO notification. Before a grid-tied system goes live, your Distribution Network Operator has to know about it - a straightforward G98 notification for most domestic systems, or a G99 application for larger ones. That's normally handled by your installer. Do it yourself and you need to lodge it yourself; skip it and you have an unregistered generator connected to the network.

What DIY costs you: SEG and 0% VAT

This is where most DIY solar projects stop making financial sense.

Smart Export Guarantee payments. To be paid for the electricity you export, your system generally needs an MCS certificate - covering both the products and the installer. You can't self-certify to MCS as a one-off homeowner. The routes around it are paying an MCS-registered installer to inspect and certify your work (if they'll take on someone else's install at all), or completing MCS accreditation yourself, which is a multi-week course aimed at businesses. Without an MCS certificate, you're generating for your own use only and giving your surplus to the grid for free.

0% VAT. The zero rate on domestic solar applies to installations supplied and fitted by a business. Buy the panels and inverter as a DIY kit and you're typically paying the standard 20% VAT on the hardware. On a mid-size system that's several hundred pounds that an accredited install wouldn't attract.

Add it up: no export income, VAT on the kit, no manufacturer-backed workmanship warranty, and a system a future buyer's surveyor may flag because there's no MCS paperwork. The panel savings often don't cover it.

When DIY solar does make sense

It's not all one way. DIY is a reasonable choice when:

• You're powering an outbuilding, workshop, stables or shed that isn't tied into the house supply
• You want an off-grid or portable setup - a campervan, a boat, a caravan, a remote cabin
• You're building a small, self-contained system - panels and a battery you'll never export from - and you have the electrical knowledge to do it safely
• You're buying second-hand panels for a low-stakes project where warranty and certification don't matter

For anything that connects to your home's electrics and where you'd want export payments, the numbers point the other way.

If a DIY system isn't performing

A lot of the systems Wave Renewables gets called to inspect are self-installs or jobs left half-finished by an installer who's since disappeared. If yours isn't generating what it should, or you got the panels up and want the connection done and certified properly, that's a normal job - solar repairs and fault finding and the electrical connection both. The free Solar Fault Find covers the diagnosis.

Weighing up a proper install instead? We quote across Norfolk and Suffolk - free site visit, itemised quote. See how solar panel installation works or get in touch.

Published September 2026. Rules on VAT, MCS and grid connection change - check the current position with gov.uk, MCS and your DNO before starting.