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Planning permission, Part P, G98/G99 and what's DIY-legal.
The good news first: an off-grid 12/24V system in a shed, garage or garden office — not connected to your house's mains wiring — is the most DIY-friendly category. No planning permission for the electrics, no Part P, no DNO involvement.
Panels and planning: roof- or ground-mounted solar is usually *permitted development* across the UK, within limits — panels shouldn't protrude far above the roof plane, ground arrays have size limits, and listed buildings and conservation areas need consent. Rules are devolved: England/Wales, Scotland and NI each have their own permitted development rules, all broadly similar but check your council's planning portal.
Fixed 230V wiring in or attached to a dwelling: BS 7671 wiring regs apply everywhere; in England & Wales it's notifiable under Part P (use a registered electrician); Scotland uses Building Standards; NI has its own building regs.
Grid-tied systems (exporting to the grid): your DNO must be notified under G98 (small) or approved under G99 (larger), and you'll need an MCS-certified installation to receive Smart Export Guarantee payments. This is professional-install territory.
New for 2026 — plug-in/balcony solar: BS 7671 Amendment 4 (in force 15 April 2026) legalised systems up to 800W feeding home circuits, with free G98 notification. During the transition, connection still runs through a registered electrician; a BSI plug-and-play kit standard is expected later in 2026. See the Balcony & Plug-in section for the full picture.
From EcoPowerful — plain-English DIY solar & wind guidance for UK homes, with a free instant system plan builder. Guidance is general; 230V fixed wiring always needs a qualified electrician. Last updated 2026-06-13.