Renovation of a chalet in a protected heritage area
A Biarritz chalet, thoroughly renovated.
This large chalet, divided into six flats, has undergone a complete energy renovation under the French MaPrimeRénov’ Copropriété scheme. Located in a protected heritage area, it was transformed with respect for its architecture while residents remained in place. Under the roof, B+L also designed an apartment suspended from the timber structure.
Built in the early twentieth century, less than 500 metres from the ocean, the chalet was barely insulated: bare walls and ground floor, a poorly insulated attic, gas boilers, no mechanical ventilation. External insulation is added on three façades, then the renders, mouldings, shutters and timber windows are remade identically; the main west façade is left as it was. From the street, the chalet keeps its original appearance.
Inside, the roof slopes and the ground floor are insulated, the windows replaced with double-glazed timber units, humidity-controlled ventilation installed, and the boilers replaced by radiant panels and a heat-pump water heater. The energy audit forecasts a 35% cut in primary energy use and a 90% cut in greenhouse gas emissions. A sixth flat is created on the ground floor, in the former garage.
This large chalet, divided into six flats, has undergone a complete energy renovation under the French MaPrimeRénov’ Copropriété scheme. Located in a protected heritage area, it was transformed with respect for its architecture while residents remained in place. Under the roof, B+L also designed an apartment suspended from the timber structure.
Built in the early twentieth century, less than 500 metres from the ocean, the chalet was barely insulated: bare walls and ground floor, a poorly insulated attic, gas boilers, no mechanical ventilation. External insulation is added on three façades, then the renders, mouldings, shutters and timber windows are remade identically; the main west façade is left as it was. From the street, the chalet keeps its original appearance.
Inside, the roof slopes and the ground floor are insulated, the windows replaced with double-glazed timber units, humidity-controlled ventilation installed, and the boilers replaced by radiant panels and a heat-pump water heater. The energy audit forecasts a 35% cut in primary energy use and a 90% cut in greenhouse gas emissions. A sixth flat is created on the ground floor, in the former garage.
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Client ︎︎︎ SOLIHA (co-ownership).Floor area ︎︎︎ 350 m².
Budget ︎︎︎ €450,000 excl. VAT.
Location ︎︎︎ Basque coast.
Specifics ︎︎︎ Energy renovation (MaPrimeRénov’ Copro) / Occupied site / Protected heritage area.
Team ︎︎︎ B+L Architects.
Status ︎︎︎ Completed 2026.
Photographs ︎︎︎ @emmymartens.