Doragno Castle - Rigid polyurethane foam insulation panels - 100 mm

The roof intervention at foragno Castle combined energy efficiency improvements with the integration of renewable energy systems, while respecting the building’s historical character. The west wing roof remained unchanged, whereas the east wing, which originally had a single sloping pitch facing north, was redesigned with a double-pitched configuration to improve functionality and architectural integration. The new roof build-up includes a photovoltaic glass panel (8 mm), two layers of insulation (100 mm Isotec and 75 mm Celenit), and a final wooden layer (27 mm). This composition significantly improved the thermal performance of the roof, reducing the U-value from 1.0 W/m²K to 0.2 W/m²K. Photovoltaic panels (100 m², 16.4 kW) were installed on the southeast and southwest slopes, together with solar thermal collectors (5 m²) for domestic hot water. All solar components were carefully integrated into the roof, with similar geometry and appearance, to ensure a uniform surface and minimize visual impact from the surroundings. This renovation approach allowed the roof to support a reversible air-to-water heat pump system and a mechanical ventilation system with heat recovery, ensuring modern comfort standards without compromising the historical value of the castle.

The 20th century works were demolished and the new parts were made of steel and glass, keeping the lines of the new volumes as simple as possible.