modern seaweed house main image

On an island where trees were scarce, crafty locals made use of an abundant, yet highly unusual building material: seaweed. Naturally insulating, seaweed requires very little effort to harvest. While it was once the traditional construction method of Læsø, it has become less popular over time, with only about twenty seaweed-clad homes remaining on the island. Architects Realdania Byg have revived it with The Modern Seaweed House, demonstrating how seaweed cladding can be harmonious with contemporary structures.

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modern seaweed house front
modern seaweed house facade

Rather than creating a replica of the historic seaweed houses that once populated the island, Realdania Byg created a contemporary home that takes its cues from the older structures. The seaweed may once have been used simply because it was available, but the architects explain that it fills 21st century demands as well as any other material.

modern seaweed house gabled detail
modern seaweed house in field

Non-toxic and fireproof, with a life expectancy of more than 150 years, seaweed is the ideal environmentally friendly material to use on the island, where it dries naturally in the sun and wind. The architects filled mesh bags with it and attached them to the roof and exterior walls of the house.

modern seaweed living room

Wooden cases of seaweed fill the walls and the space beneath the floor, as well. The architects report that they’re remarkably acoustic, and also absorb and give of moisture to regulate the indoor climate naturally.  They hope the project will inspire other builders to create similar houses.

“Seaweed is at the same time very old and very ‘just-in-time’, because it is in many ways the ultimate sustainable material,” Realdania Byg’s Jørgen Søndermark told Dezeen.

“It reproduces itself every year in the sea, it comes ashore without any effort from humans, and it is dried on nearby fields by sun and wind,” he continued. “It insulates just as well as mineral insulation, it is non-toxic and fireproof, and it has an expected life of more than 150 years!”

“By using seaweed in the construction, we not only secure the continued supply of seaweed for use on the historic houses, we also reintroduce a material to the modern building industry which is CO2-reducing, environmentally friendly and sustainable in a broader sense,” said Søndermark.