Swiss architect and renovation specialist Barbara Buser advises homeowners to prioritise invisible infrastructure over visible upgrades when renovating older properties, arguing that structural soundness and energy efficiency should come first.
Buser, who conducted a detailed inspection of a property from cellar to roof, looks for cracks, moisture traces and insect damage — particularly in the basement and floor screed, where the air should smell dry and clean. Surface wear such as worn stair treads or flooring, she says, is irrelevant to the building's structural quality.
She advocates salvaging what can be reused rather than demolishing. Components that can be dismantled without damage — solid timber floors, doors, windows, kitchen units and sanitary fittings — are frequently candidates for reuse. Sanitary pipes can often remain in place if they pass inspection, though electrical installations commonly require replacement to meet current regulations; sometimes only a new circuit breaker is needed. Radiators may also be retained, but Buser recommends replacing the heat source — the boiler — with a more environmentally friendly option.
Windows do not always need full replacement, she notes. Many can be upgraded to comply with modern standards. Interior doors, however, generally must be strengthened or replaced to satisfy new fire-protection norms.
Buser warns that demolition is often the costliest mistake. Beyond theCO2 emissions and waste generated by tearing down, she argues that older materials frequently exceed new ones in quality — citing century-old solid oak parquet as an example. "Old materials bear traces of use; they have a history you can feel," she said. "Once you start ripping things out, you don't know when to stop, and suddenly the entire atmosphere is destroyed."
Along with her daughter, Buser rescues high-quality Forster steel kitchens that could technically last a hundred years but are routinely discarded after twenty. The cabinets, built from standardised elements, can be reconfigured into any layout. They are paired with refurbished, factory-tested appliances — hobs, ovens, refrigerators — or brand-new units, and repainted in a colour chosen by the owner.
When asked about the order of renovations, Buser was blunt: "Unfortunately, you must deal with the invisible first — the structure, insulation, and electrical, water and wastewater lines." She acknowledged the frustration: these upgrades are expensive and unseen, yet they should provide decades of trouble-free living. Visible improvements — kitchens, bathrooms, wall colours — come afterwards.
On whether to extend upward or outward, Buser pointed to her firm's K.118 project in Winterthur, which added floors to an existing building. Roof extensions are worthwhile when the roof already needs remediation and insulation, yielding more living space per franc than a ground-level extension, which requires new foundations and a new roof envelope. Ultimately, cantonal building laws determine what is permissible.
On energy efficiency, Buser cautioned that the embodied energy and CO2 required to manufacture new windows is often never recovered through reduced heating consumption. Keeping original window profiles — by doubling them, upgrading existing units, or replacing only the glass — can preserve a building's character while improving performance.
Swiss cantonal subsidies for insulation and boiler replacement exist, but Buser said the amounts are too small to drive major decisions; psychological factors carry more weight.
Among the most underestimated hurdles, she cited lengthy building-permit approval times across many cantons, which increase costs, and the need to obtain neighbour consent for boundary-adjacent work to avoid delays from objections. Early consultation with heritage and townscape authorities, she added, typically leads to workable solutions.
Cost overruns, Buser warned, rise with each structural change required to adapt a building to a new use. The closer the new use matches the old one, the fewer modifications are needed and the lower the cost. Finally, she stressed that choosing contractors on price alone is risky: "The cheapest can quickly become the most expensive."
