She further noted that “modern technological developments in the construction sector create new requirements and complex fire safety challenges. Buildings are becoming increasingly complex, taller, and more energy efficient, while issues such as fire spread, material behavior at high temperatures, emission of toxic by-products, fire protection of energy installations, and the safety of high-rise buildings are now at the forefront of scientific and technical discussion.”

Fire protection constitutes a key component of sustainability, as it enhances energy and operational performance, ensures the continuous operation of infrastructure, and contributes to a more favorable environmental balance throughout the building lifecycle. Photovoltaic (PV) systems introduce an additional fire risk factor, mainly due to DC voltages, cabling, and inverters. Therefore, passive fire protection measures are critical for limiting fire spread and protecting the building envelope.

A comprehensive fire protection design, its proper implementation, and the appropriate selection of materials significantly reduce the likelihood of fire ignition and spread, while also extending the lifespan of installed systems and enhancing the overall resilience of the building stock. Particular importance is given to roof fire performance, which is assessed as a unified system, i.e., the combination of the PV installation with the configuration and materials of the roof. This parameter becomes even more critical in municipal and public buildings, such as educational and cultural facilities, where operational continuity and user safety are of paramount importance.

Regarding reaction to fire, the use of certified PV panels and mounting systems is recommended, along with cladding materials of high fire resistance class, such as A1 or A2 according to EN 13501-1. At the same time, combustible substrates, such as unprotected bituminous membranes, should be avoided, while non-combustible or low-flammability insulation materials and membranes are recommended. In particular, for flat roofs with thermal insulation, fire compartmentation is essential. This can be achieved by interrupting continuous PV arrays on large roofs, creating fire breaks, and aligning layouts with the building’s fire compartments.

PV panels should be installed at adequate distances from critical structural elements such as stairwell exits, skylights, ventilation ducts, and other service penetrations, while ensuring the required access zones for firefighting operations, in accordance with applicable regulations. Particular attention is required in large-scale installations, where the provision of access pathways, perimeter clearances, and fire compartmentation zones is crucial both for limiting horizontal fire spread and for ensuring safe and immediate emergency response.

Special emphasis should be placed on fire stopping at penetrations and in transformer areas, as well as on maintaining minimum required clearances. Cables should not run uncontrolled over fire-resistant separating elements; alternatively, they should be installed within fire-resistant conduits or shafts. Where PV cabling penetrates slabs, walls, or roofs, fire-resistant sealing materials and specialized collars/wraps must be used to maintain the required fire resistance rating (EI).

Equally important is the passive fire protection of cabling through:

• the use of low smoke zero halogen (LSZH) cables
• installation on metal trays or conduits
• avoidance of contact with combustible materials
• appropriate protection when crossing fire compartments and floors

Separate fire compartmentation is also required for electrical rooms, DC/AC inverters, and battery storage systems, using fire-resistant walls (e.g., EI 60), fire-rated doors, and avoiding installation along escape routes. In addition, adequate emergency lighting must be provided in accordance with applicable standards. Additional safety systems, such as properly located fire extinguishers, fault detectors, and arc fault detection devices, contribute to the immediate shutdown of inverters and electrical circuits. Similarly, automatic PV shutdown systems and spark detection further enhance overall fire safety.

It is evident that fire protection design can significantly influence the performance, resilience, and environmental responsibility of a building. It affects both the thermal and mechanical stress on the building envelope and the preservation of the load-bearing structure, while ensuring operational continuity.

Furthermore, it reduces the carbon footprint associated with the production and use of new repair materials, their transportation to the site, and the additional energy required in the event of repair or reconstruction.

In conclusion, fire protection is not merely a technical compliance requirement but a fundamental parameter of sustainable design. A building capable of withstanding extreme conditions, such as fire, maintains its functionality, extends the lifecycle of its infrastructure, and demonstrates a significantly lower environmental footprint over its lifecycle. In this sense, passive fire protection is directly linked to resilience, sustainability, and the long-term energy performance of the built environment.