Can I install solar panels without authorisation?
It depends: on the roof, for self-consumption, usually no permit — but with notice. For photovoltaic panels mounted on the roof of an existing building, for self-consumption and with power under 400 kW, you do not need a building permit (an amendment to Law 50/1991). Even so, the law requires a prior notification to the town hall, at least 30 days before work starts. A permit becomes necessary if you mount the panels on land separate from the house, if the work involves large structures, foundations or pillars, or if the installation exceeds 400 kW or is commercial. To become a prosumer and inject energy into the grid, you need the technical connection approval (ATR) from the distribution operator, without which you can't sign the connection contract. Always check the rules at your local town hall, as they can differ.
📋 The rules
- Roof + self-consumption + under 400 kW: no permit
- Notify the town hall at least 30 days ahead
- Separate land / large structures / over 400 kW: permit
- To inject into the grid: connection approval (ATR)
- Different local rules: check at the town hall
🔓 Exceptions
- Roof mount for self-consumption: exempt from a permit
- Commercial installation or over 400 kW: permit mandatory
- Protected buildings/areas (monuments): extra requirements
⚠️ Penalties & fines
Carrying out works without a permit, where one is required, is sanctioned with substantial fines and can even lead to demolition of the structure at the owner's expense. Failing to notify the town hall, or injecting energy into the grid without an ATR and prosumer status, can block the connection and bring sanctions. To stay compliant: work out whether your project is in the exempt category (roof, self-consumption, under 400 kW), file the notification with the town hall 30 days ahead, get the connection approval from the distributor, and if you want to sell the surplus, register as a prosumer with the supplier. Always ask the local town hall for official information before signing the installation contract.
📎 Official sources
- Law 50/1991 on authorising construction works →
- ANRE · how to become a prosumer →
- Ministry of Development, Public Works and Administration →
❓ Frequently asked
Do I need a permit for solar panels on the house?
Usually no, if you mount them on the roof of an existing building, for self-consumption and with power under 400 kW. In this case, Law 50/1991 exempts you from the building permit. You must still file a prior notification with the town hall, at least 30 days before the works start.
When is a building permit mandatory?
When you mount the panels on land separate from the house, when the work involves large metal structures, cast foundations or pillars, or when the installation exceeds 400 kW or is commercial. In these cases the exemption no longer applies and you need an urban-planning certificate and a permit.
What is the connection approval (ATR)?
It's the document issued by the distribution operator without which you can't sign the connection contract, can't receive prosumer status and can't inject energy into the grid. In practice, the ATR is the key step if you want not only to consume but also to deliver your energy surplus to the grid.
Must I notify the town hall even if I'm exempt?
Yes. Even when you're exempt from the building permit, the law requires a prior notification to the town hall, at least 30 days before the works start. In addition, rules can differ from one locality to another, so it's advisable to ask for official information before installing.
What do I risk installing without a permit where it's needed?
Carrying out works without a permit, where one is required, is sanctioned with large fines and can even lead to demolition of the structure at your expense. That's why it's important to determine correctly, from the start, whether your project is in the exempt category or needs a permit.
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