A long running legal dispute about the design of an umbrella shaped to withstand strong winds took another short step towards completion on Thursday when judges in The Hague ruled that basic technical requirements cannot be considered part of the design.

The court said that umbrellas developed by Dutch company Impliva do not encroach on the rights of design group Senz, which claims to have developed the first storm umbrella in 2006 and had taken Impliva to court.

The court said the shape of the umbrellas is partly determined by technical requirements [for coping with strong wind]. ‘This means relatively small differences are sufficient,’ the court said. ‘Viewed from above or below, there are clear differences [between the two designs].’

Senz, founded by former Delft University students, said it was disappointed in the ruling, which shows that design rights in the Netherlands are ‘extremely fragile’. The company is planning to appeal.

The case dates back to 2007 when a court in The Hague first found in favour of Senz. That ruling was overturned by the EU’s intellectual property office (EUIPO) and then turned back again by the European court of justice in Luxembourg last year.