Whether it is illegal to build a light - steel villa in France depends on various policies and regulations. Here is an interpretation of the relevant 2025 policies:

　　Building regulatory framework and compliance requirements

　　- Structural safety standards: According to the latest revised "Code de la construction et de l'habitation" in 2025, light - steel villas must comply with the NF EN 1993 - 1 - 3 standard, which is the design specification for cold - formed thin - walled steel structures. In terms of earthquake resistance, areas like Paris require compliance with the PS92 standard, meaning the building should be able to withstand a magnitude 6 earthquake to ensure its safety during natural disasters such as earthquakes.

　　- Energy efficiency indicators: Light - steel villas need to meet the RE2020 environmental protection standard. The overall building energy consumption should be controlled at ≤50 kWh/m²/year, and the carbon emissions should be ≤4 kgCO₂/m². This reflects France's emphasis on environmental protection and energy efficiency in the construction field. Appropriate materials and technologies need to be adopted in the design and construction process of light - steel villas to meet these indicators.

　　- Fire - resistance performance requirements: The wall system should reach the EI60 fire - resistance rating, that is, it should have a fire - resistance time of 60 minutes to provide time for personnel evacuation and fire rescue in case of a fire.

French client visits Ruijie Light Steel Villa Company for inspection

　　Regional planning restrictions

　　The local urban planning documents (PLU) of each municipality in France have different control requirements for buildings in different areas:

　　- City center areas (Zone UA): For example, in the 1st - 6th arrondissements of Paris, to maintain the overall urban style and historical and cultural characteristics, light - steel villas need to have at least 70% facade similarity with the surrounding traditional buildings.

　　- Rural expansion areas (Zone AU): Such as rural areas in Provence, although the construction of light - steel villas is allowed, the building height is restricted, generally requiring ≤2 floors to avoid excessive impact on the rural landscape.

　　- Heritage protection areas (Zone PP): Like the Loire Valley castle area, due to the protection of historical and cultural heritage, the use of non - traditional building materials is completely prohibited. Therefore, it is not allowed to build light - steel villas in such areas. However, in ecological innovation demonstration areas (such as Lyon's EcoVallée), to encourage architectural innovation and ecological development, light - steel buildings can get a floor area ratio bonus (+15%).

Ruijie Light Steel Villa Construction Team

　　Legal regulations in the construction process

　　- Permit application system: Different approval paths need to be selected according to the building scale. If the building area is less than 20㎡, only a prior declaration (Déclaration préalable) needs to be submitted; if the building scale is between 20 - 150㎡, a simplified building permit (Permis de construire simplifié) should be applied for; if it exceeds 150㎡, a full building permit (Permis de construire) is required, and an environmental impact assessment may be necessary. The municipal government is required to complete the approval within 2 months. According to the new clause in the 2024 "Housing Acceleration Act", if the approval is overdue, it will be regarded as a default permit.

　　- Professional qualification requirements: All parties involved in the construction must have the corresponding professional qualifications. The design party should be an architectural firm certified by OPQIBI, the construction party should have the Qualibat 2312 special qualification for steel structures, and the supervision party should be a quality control institution certified by CQPA. Since 2025, all light - steel component suppliers must pass the Batiment Biosourcé 3 - level certification.

　　Market - related policies and impacts

　　- Supportive policies: The 2025 white paper of the French Ministry of Ecological Transition shows that projects of light - steel villas that obtain the BBCA low - carbon certification can get a tax credit of up to 15%, which encourages builders to use more environmentally friendly light - steel materials and construction technologies.

　　- Restrictive policies: It is proposed to levy an ecological surcharge of 8€/kg on non - recycled steel (to take effect in 2026), which may affect the construction cost of light - steel villas and prompt builders to use more recycled steel.

　　In conclusion, building a light - steel villa in France is not necessarily illegal, but it is necessary to strictly comply with relevant building regulations, regional planning requirements, and construction process regulations. Before starting the construction, it is recommended to understand the specific local policies in detail and consult professional architectural and legal personnel.
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