The façade is the largest surface area of the house and the biggest lever for heat loss. Façade contractors render, insulate, paint and repair cracks and moisture damage. Because scaffolding is the most expensive part, it is almost always worth planning insulation, painting and window replacement in one go rather than spreading them over years.
It installs rendered external wall insulation systems, refurbishes existing rendered façades, treats cracks, renews paint finishes and installs ventilated cladding. This also includes plinth areas, window junctions and the detailing at roof edges, balconies and penetrations. In many companies, painting work is part of the same business.
External wall insulation noticeably reduces heating demand, but it is the most expensive single measure on the building envelope. It makes most sense when the façade needs refurbishing anyway, because scaffolding and rendering are then only needed once. There are funding programmes from the Confederation and the cantons for energy-efficiency measures, with different conditions; as a rule, they must be applied for before work begins.
If the façade is insulated, the reveal depth of the windows changes. If the windows are replaced later, the insulation has to be opened up again around every opening. Conversely, a new window in an uninsulated wall is often positioned at the wrong depth within the wall. Plan both trades together, even if you phase them over time.
External wall insulation changes the volume of the building, and the colour often changes its appearance. Both may require a permit; stricter rules apply in core, townscape and protected zones, up to and including a ban on external insulation. The rules vary by canton and municipality; clarify them before finalising materials and colours.
Ask for the area in square metres minus openings, the complete system build-up including insulation material, thickness and finish render, and a separate breakdown for plinths, reveals, window sills and junctions. Scaffolding, substrate preparation and disposal should also be included. Details at reveals and plinths are where quotations differ in price.
If a damp wall is insulated, the problem does not disappear; it moves indoors and shows up as mould. If there are damp patches, rising damp at the plinth or flaking render, the cause must be clarified before insulating. This falls under building waterproofing, not the façade contractor. Keeping to this sequence is the most cost-effective measure in the entire project.