The former mill of the 13th century in Sissach near Basel was comprehensively renovated in the years of 2012 to 2014 under the supervision of the corresponding office of monument preservation . The status analysis showed that the largest part of the thermal losses was due to the façade with approximately 48%. Another 23% of the energy was transmitted via the roof and the attic, respectively. Before the renovation, the façade consisted of a 60 to 70 cm thick quarry stone brickwork made of limestone, which narrows down to 40 cm on the 3rd floor. The walls carried a non-historic exterior plaster. The u-value of this wall was about 1.1 W/(m²·K). In addition to other measures, the windows were replaced during the renovation, the attic floor was insulated and an external thermal insulation was realized with the Fixit 222 aerogel insulating plaster. For that, the existing plaster was removed and replaced by an insulating render of average thickness of 50 mm. In this way, approximately 440 m² of façade were renovated. The u-value after the energetic upgrade is about 0.4 W/(m²·K). Overall, the renovation measures led to a reduction of primary energy consumption of approximately 60%. The renovation was certified according to Minergie. All information according to  and personal communication Emil Franov, Carbotech AG. Also this renovation would not have been possible to be realized with conventional insulation materials, because either the window details would have disappeared under a thicker insulation or the thermal envelope could have been improved only slightly, e.g. with a conventional insulating render.