External insulation with curtain walls and cavity wall insulation

Curtain walls consist of an insulation layer mounted on the outer face of the load-bearing external wall, and façade panels mounted externally, usually with an air space behind.

A video on building a curtain wall:
https://youtu.be/23zRoOuszxo

Structure of a façade with air space behind (source: www.FVHF.de, adapted)

The great advantage of curtain walls is the free choice of materials.

Disadvantages arise because the fastening system involves thermal bridges

If the existing external wall is double, cavity wall insulation can be fitted in the space between the two walls.

It is important that the cavity is at least 5 cm wide everywhere and can be filled up with insulation material completely, in order to avoid thermal bridges as much as possible.