1. Check the building and procedures
Ask the municipality which requirements apply to building use, works and zoning. Clarify property rights and constraints of any existing connection. A small electrical installation does not constitute permission to occupy a building. Avoid a general promise that every municipality permits or prohibits the project.
2. Design a safe installation
The SFOE describes the OIBT as the framework for low-voltage electrical installations, including technical rules, authorisations and inspections. Have competent professionals confirm requirements for your installation. Specify protection, earthing, source separation, diagrams and tests. Absence of a public grid does not remove electrical hazards or the need to check compliance.
3. Size for difficult periods
List essential and flexible loads with power and duration. Request a seasonal simulation covering shade, snow, temperature, losses and days with little sunshine. Usable battery capacity and inverter power impose different limits. One night’s reserve does not constitute seasonal winter storage.
4. Define supply continuity
Simulate low battery charge, faults and unavailable equipment. Define priority loads and an intervention procedure. If another source is proposed, check connection, emissions, noise, fuel and site requirements. Do not assume that a portable generator can supply the building without a suitable installation.
5. Compare full costs
Compare a grid connection, grid-connected solar with backup and independent supply for the same demand. Include batteries, protection, works, maintenance, consumables and replacement. Ask who can attend the site and how quickly. Check grants or tax consequences separately; the term off-grid does not establish eligibility or savings.