Glossary
NF C 15-100: the French electrical installation standard
Quick definition
NF C 15-100 is the French standard that governs how low-voltage electrical installations (230V/400V) must be designed and built in residential properties. Published by AFNOR (Association Française de Normalisation), it sets minimum requirements for circuit quantities, cable sizing, circuit protection, earthing, and safety in specific rooms. It is referenced on every CONSUEL conformity certificate and is the baseline against which all French residential electrical work is assessed.
What does NF C 15-100 actually specify?
The standard covers a wide range of technical requirements. The most relevant to homeowners undertaking energy renovation work:
- Circuit allocation by room: minimum number of circuits and socket outlets per room type. Kitchens, for example, require multiple dedicated circuits for high-draw appliances (oven, hob, dishwasher). The standard specifies these minimums regardless of what the previous owner installed.
- Residual current devices (RCDs, or disjoncteurs différentiels): the standard requires adequate RCD protection at the consumer unit (tableau électrique). Modern compliant boards have multiple 30mA RCDs protecting groups of circuits, rather than a single device for the whole installation.
- Earthing (mise à la terre): all circuits must be earthed. Older two-pin sockets without an earth connection are non-compliant. Bathrooms have specific equipotential bonding requirements.
- Cable sizing: minimum cross-section for each circuit type, ensuring cables can safely carry the load without overheating.
- Specific zones: bathrooms, outdoors, and swimming pool areas have specific volume-based rules governing which types of fittings and circuits are permitted where.
Why do many older French properties fail it?
The standard has been revised several times, most significantly in 2002 and with amendments since. A property wired in the 1960s, 1970s, or even 1980s may not comply with the current version in several ways:
- No earthing on older socket outlets
- Single RCD protecting the entire installation, rather than multiple devices by circuit group
- Insufficient circuits in kitchens (one circuit for everything rather than dedicated appliance circuits)
- Inadequate equipotential bonding in bathrooms
- Consumer unit without adequate space or protection for modern circuit loads
This is common in Alpes-Maritimes and Var properties, particularly older apartments and villas that haven't had electrical work done since their original construction. Non-compliance is not automatically illegal for an owner-occupier in a primary residence, but it has practical consequences.
When does compliance actually matter?
NF C 15-100 compliance is required or assessed in specific situations:
- New construction: the installation must comply before CONSUEL issues the conformity certificate and Enedis connects the supply.
- Major renovation: if you're doing significant electrical work, the new or modified circuits must comply. A full rewire brings the whole installation under the standard.
- Selling a property: the electrical diagnostics report (part of the Dossier de Diagnostic Technique) notes non-compliances. These don't block a sale but inform the buyer and can affect negotiation.
- Renting a property: landlords must ensure the electrical installation presents no safety hazard. Non-compliant installations, particularly those without earthing or RCD protection, can create insurance and liability issues.
- Insurance claims: if an electrical fault causes a fire in a non-compliant installation, the insurer may dispute the claim. Compliance is not only regulatory but practical.
How does NF C 15-100 relate to energy renovation work?
Several types of energy work that Riviera Home Experts connects clients with require interaction with the electrical installation in ways that touch NF C 15-100:
- Heat pump installation: the heat pump requires a dedicated circuit sized to its electrical draw. Any new dedicated circuit must comply with the standard's sizing and protection requirements. If the consumer unit is full or old, it may need upgrading as part of the heat pump installation.
- EV charger installation: IRVE-certified installers follow NF C 15-100 plus the specific EV charging annex (guide UTE C 15-722). A dedicated 32A or 40A circuit is required.
- Solar PV: the consumer unit modifications required for a grid-tied solar system must comply, and the CONSUEL check covers the full installation.
If an electrician identifies non-compliances in your existing installation during a site visit for energy work, they may recommend remedial work before or alongside the main job. This is legitimate: connecting high-draw equipment to an already-compromised installation can create safety risks.