Fire experts have warned that developers need to rethink the practice of covering the roofs of renovated homes in solar panels following this week’s fire in Arnhem, which was difficult to put out because water could not reach the flames.

Five homes were completely destroyed in the blaze and three suffered serious smoke and water damage after the fire ripped across the roof of the terraced housing. The fire broke out in the kitchen of one of the units but quickly spread to neighbouring homes via the roof.

The terrace was renovated about seven years ago to meet new sustainability standards, with solar panel roofs and an extra layer of insulation on the façade and the roof. Thousands of social housing units have been updated in this way across the country.

Eindhoven University professor and fire expert Ruud van Herpen told Dutch News it is lucky that no-one has yet been killed. “I think we need to go look at what we want to achieve in fire safety instead of applying rules and regulations according to the building code,” he said.

“The building code is for traditional buildings built with traditional materials. It does not anticipate innovative solutions. We have to think about the risks and what can be done to prevent fire spread. I don’t think anyone thought about the risks of fire spread when they came up with this type of construction.”

“Many large companies use more or less the same renovation concept – a new shell on the outside of existing building – and there is the problem,” he said.

“You don’t need to inspect every renovated residential building but checking the drawings and seeing if the roof bypasses the fire safety compartments would make sense.”

There are currently no building regulations about the use of solar panels on roofs. Nor is there a standard certification system for technicians who install them.