When does design become art?

Furniture and chairs such as the famous Le Corbusier chairs and sofas, the USM Haller office furniture programme or the design of the Vespa motor scooter are predestined for design protection. But what happens if the design protection has expired after 25 years at the latest or if it was even missed, for example because the furniture was marketed too early or the application for design protection was filed too late with the responsible office, so that the design law protection criterion of "novelty" was no longer fulfilled?

Outstanding designs can be legally judged as art. If they qualify as works in the sense of copyright law, they fall under copyright protection with a much longer term of protection (70 years after the death of the author/creator).