Fire protection for solar systems starts at three points: a clean electrical installation (by far the most common cause of fire is faulty DC connectors), the labelling of the system and a means of disconnection so that the fire brigade can work safely in the event of an incident, as well as clearances on the roof. The most important regulation is also the most unspectacular: professional installation. A correctly installed system is the best fire protection. (As of: July 2026)
Key points in brief
- The most common cause of fire is the electrics – poorly placed DC connectors, not the module itself.
- Therefore, professional installation is the most effective fire protection measure, not additional equipment.
- Requirements concern labelling, a means of disconnection for the fire brigade and clearances.
- The system is checked by an independent inspection after installation – this is part of the protection concept.
- The authoritative details are set by the VKF fire protection regulations; they are periodically adjusted.
Where does a fire risk even arise with a solar system?
Almost always in the same place: on the direct current side, specifically at the connectors and contacts that carry the current from the modules to the inverter. A loosely crimped or incorrectly paired connector creates contact resistance that can heat up over years – this is the dominant cause if an incident occurs at all. The module itself is rarely the trigger. The connections and the widespread myths are covered in detail in the article Fire risk with solar systems.
This leads to the central insight of fire protection: It is not created by retrofitted equipment, but is decided on the day of installation. Cleanly placed connectors, correctly dimensioned and routed cables, professional protective devices – that is effective fire protection. Everything else are additions for the event of an incident.
What do the regulations specifically require?
The VKF fire protection fact sheet «Solaranlagen» (2001-15, valid since 1 January 2022) is authoritative, together with the general VKF fire protection regulations and the NIN installation standard. The good news first: Surface-mounted solar systems with a non-combustible outermost layer may be installed on flat or pitched roofs that comply with regulations without further fire protection requirements – this is the normal case for a single-family home. The specific requirements mainly concern three areas:
Labelling. A solar system carries voltage on the direct current side even when the inverter is switched off, as long as the sun is shining. The fact sheet therefore requires a weather-resistant hazard warning on the building and an orientation plan for the fire brigade – with the locations of the modules, DC cables and the inverter. In addition, the building owner informs the fire brigade command about the installation; in practice, this is handled by the documentation from the specialist company.
Safe DC cable routing. All DC cables must be implemented with double insulation and without PVC; depending on the installation location, graded requirements apply to routing in a protective conduit. In vertical escape and rescue routes, DC cables are only permitted in ducts or shafts with sufficient fire resistance, and the inverter does not belong in rooms with a risk of fire or explosion. Kept short DC routes – inverter close to the solar array – are explicitly recommended. The underlying protection technology – disconnection points, overvoltage protection – belongs to the electrical installation of the system and is specialist work.
Clearances and fire protection equipment. Solar systems must not impair the effectiveness of fire walls and smoke and heat exhaust ventilation systems: A clearance of 2.0 m to SHEV openings is considered met without additional measures; if it is not reached, the modules must be arranged within the clearance gauge. On a flat roof, clearances also interact with the statics, as the article Flat roof regulations shows.
| Requirement | Core requirement (VKF 2001-15) | Responsibility |
|---|---|---|
| Labelling | Hazard warning + orientation plan, fire brigade informed | Installer / documentation |
| DC cables | double insulation without PVC, protected routing, not in vertical escape routes | Specialist company |
| Inverter | outside rooms with a risk of fire/explosion, close to the solar array | Planning / installation |
| SHEV openings | Clearance 2.0 m without additional measures | Planning |
| Fire walls | Effectiveness must not be impaired | Planning / installation |
Simplified overview, as of: July 2026 (VKF fire protection fact sheet 2001-15, valid since 2022). The requirements are periodically adjusted and must be checked on a project-specific basis; in special cases such as fire-hazard rooms (e.g. agriculture) or integrated large systems, additional requirements apply.
Who checks that everything is correct?
At the end of every installation there is an independent inspection of the electrical installation – this is not a formality, but the system's built-in check step. Unprofessional or sloppy electrics are noticed here before they become a problem. That is why the question of who installs and accepts the system is central in terms of safety: The inverter and the wiring belong in the hands of a specialist company, not in a DIY project.
The connection to the price is uncomfortable, but honest: Saving money on the mounting system and the electrics is exactly the wrong cost-saving exercise – this is where the defects lie that you cannot see and that become the most expensive in the event of an incident. A visible premium module on a sloppily wired system is the wrong setting of priorities.
When someone asks us about fire protection, they often expect a list of additional equipment that you would have to buy. The honest answer disappoints at first and then reassures: The most effective fire protection does not cost any additional equipment, but lies in the care taken during installation. When taking over third-party systems, we occasionally see where savings were made – and it is almost always the DC side, the connectors. A cleanly placed contact looks like any other; a poorly placed one too, until it makes itself noticed after years. That is why the most important fire protection question is not «Which equipment?», but «Who installs – and who checks?».
Frequently asked questions
Is a solar system a fire risk?
With professional installation, the risk is low. Where an incident occurs, the cause is almost always on the direct current side – poorly placed connectors – and thus the installation quality, not the module. Therefore, clean installation by a specialist company is the most effective protection measure.
Does the fire brigade have to be able to switch off the system?
The system must be designed and labelled in such a way that emergency services can work safely in the event of an incident – this includes the possibility of bringing it into a safer state, and recognisable documentation. The specific requirements are set by the VKF fire protection regulations and must be checked on a project-specific basis.
Can the fire brigade not extinguish a house with a solar system?
Yes they can – that is a persistent myth. Emergency services are prepared for systems under voltage and work according to corresponding rules. The prerequisite is that the system is correctly labelled and implemented. The article on fire risk clears up this and other myths.
Who checks whether the electrics are compliant with fire protection?
Every installation is finally checked by an independent inspection of the electrical installation. This is a fixed part of the process and does not fall within the responsibility of the homeowner, but that of the specialist company and the inspection body. It is precisely this step that makes the choice of a reputable installer so important.
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Sources: VKF fire protection fact sheet «Solaranlagen» 2001-15 (valid since 1.1.2022); VKF fire protection regulations; SN 411000 (NIN) and SNR 460712 (labelling); requirements for electrical installation and inspection (ESTI/NIV); empirical values from installation and takeover projects of ecoEn GmbH, Zurich region.
Last updated: 9 July 2026 · Author: ecoEn editorial team
