Anyone designing a metal roof or facade today faces a problem that, until a few decades ago, wasn't even part of the technical considerations: copper, precisely because of its high value as recyclable scrap, has become a recurring target for theft from building sites, churches and public buildings — a phenomenon repeatedly flagged by insurance companies, dioceses and heritage protection associations, which intensifies during periods when the price of copper is particularly high on international commodity markets. Added to this is a second, more predictable but equally concrete factor: the cost of laying copper (€120–200/m² by current estimates) is markedly higher than zinc-titanium (€80–130/m²) and, above all, aluminium, making non-ferrous alternatives an increasingly frequent choice — not for technical superiority, but for a calculation of risk and budget the designer can't ignore.
Copper theft: a problem of value, not of building security
The paradox of architectural copper theft is that it almost always involves buildings that, by definition, shouldn't be easy targets: churches, historic buildings, public structures often fitted with surveillance systems. But roofing copper, once stripped and taken to a scrapyard, is almost impossible to trace back to its origin — unlike an identifiable artwork or architectural element, copper that's melted down or simply accumulated as undifferentiated sheet loses any connection to the building it came from. This makes roof copper a low-risk, high-return target for thieves, a criminal calculation that intensifies precisely when copper prices rise on international markets — a correlation documented by multiple insurance and heritage-protection sources over the past two decades.
Zinc-titanium: the performance closest to copper, at a lower cost
Among the alternatives available, zinc-titanium (the VMZINC and Rheinzink brands) is the one closest to copper in physical behaviour: it too develops a protective patina (basic zinc carbonate) that drastically slows corrosion, it's laid with the same standing-seam techniques, and it has a comparable lifespan in non-aggressive environments (80-100 years against over 100 for copper). The economic advantage is real but not enormous — around 30-40% less than copper — and zinc's scrap value, while significant, is markedly lower than copper's, making it a much less attractive target for theft. The main performance limit concerns marine environments with a strong presence of chlorides, where zinc-titanium is less resistant than copper and requires specific checks before it's specified for a project.
Anodised aluminium: the most economical compromise
Anodised aluminium represents the sharpest jump in terms of cost and theft risk: its scrap value per kilogram is a fraction of copper's, its lightness (2,700 kg/m³ against copper's 8,900) also reduces the cost of supporting structure, and its corrosion resistance — provided by the alumina oxide film that forms spontaneously at the surface, reinforced by anodising — is more than enough for most non-marine urban environments. The trade-off is in appearance: anodised aluminium doesn't develop a patina that changes over time the way copper or zinc do — it stays substantially identical from installation to the end of its service life, an advantage in predictability for anyone who wants a constant appearance, but a clear sacrifice for anyone who was looking, precisely in copper, for that quality of a material that "visibly ages".
A choice that's no longer just aesthetic
The result of these economic and security factors is that, in many contemporary projects — especially public buildings in high-theft-risk areas, or projects on tight budgets — the decision between copper and its non-ferrous alternatives gets made before it even reaches the table of aesthetic discussion. This isn't a decline of copper as a material: it remains the reference choice for high-profile projects where budget allows and risk is managed with adequate security measures. But for a growing slice of public construction and routine maintenance of historic heritage, zinc-titanium and aluminium have stopped being a technical fallback and have simply become the more rational choice.