Refurbishing an occupied building is a different problem from building a new wall. The existing wall may be structurally sound but out of plumb, the services are buried in it, and the finish is failing. Demolishing it means dust, noise, temporary works and a long programme in a space that has to keep operating.
The dry-hung solution leaves the old wall in place and builds a new plane in front of it. The build-up is a 33 mm integrated decorative module, a 5 mm clip assembly, levelling bolts and a 5 mm metal skirting: a minimum wall thickness of 38 mm, about 17 kg/m2. The levelling bolts correct the out-of-plumb of the original wall, so the new face is flat even though the old one is not.
The gap between the two planes becomes the service zone. Cables and small pipes are rerouted into it, which separates them from the structure and from the acoustic layer, and makes them accessible later. The original wall keeps its mass and its contribution to the acoustic separation, and the new layer adds absorption and decoupling.
The magnetic variant does the same job with a magnetic fixing instead of a clip, for positions that need frequent access — risers, service cupboards, access panels. Both variants are removable, which matters on a refurbishment where the next change is likely within a few years rather than decades.