The detached house from 1926 shown in image 2 was energetically upgraded in 2011. In addition, a gentle façade renovation was implemented. By blowing aerogel granulate into the 9 cm wide cavity in the cavity wall the u-value was reduced from about 1.1 W/(m·K) to about 0.17 W/(m²·K) (communication AGITEC and ). For this, injection holes were drilled in the façade. No other material suitable for blowing in would have allowed a similarly strong improvement of the thermal envelope, which is why aerogel granules are excellently suited for this application. One disadvantage is that the granules are partly broken by the blow-in process and can pass through fine cracks out of the cavity wall into the interior. This means that such a renovation cannot be implemented while the building is in use and it requires a final cleaning. The presented renovation was planned by AGITEC AG and executed by AGI Solothurn AG.