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Check electrical permit and inspection rules

Off-grid power systems involve high-current DC, batteries and often mains-voltage AC wiring. Most jurisdictions control who may do this work and how it is checked.

How

1. Ask the building or electrical authority whether a permit is needed for a standalone solar, wind or battery system, and which electrical code applies.
2. US example: the IRC includes electrical provisions taken from the National Electrical Code (NFPA 70), but adoption and amendments vary by jurisdiction.
3. England and Wales example: under Part P of the Building Regulations, installing a new circuit, replacing a consumer unit, or altering circuits in special locations such as bathrooms is notifiable. It must be done by an installer registered with a competent person scheme or certified by a registered third party.
4. Ask whether you may do any of the work yourself and which stages must be inspected or certified.
5. Ask whether there are specific rules for battery rooms or battery placement and for backup generators.
6. Record the answers in your permit register (next step) and pass them to the power module design.

Safety: Battery banks and inverters can deliver very high fault currents. Do not energise any system before it has been checked as your local rules require.

Do these first

• legal-1
• power-1

Sources

1. The International Residential Code. International Code Council, accessed 2026-11
2. Part P (England and Wales). The IET (Institution of Engineering and Technology), accessed 2026-11
3. Part P: electrical safety. Planning Portal (England), accessed 2026-11

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