Back in the Middle Ages, the Danish island of Læsø found itself with sparse building materials, leading the industrious population to start building with whatever natural materials they could find. Among these materials? Eelgrass, which they used to create extremely durable roofs that have lasted centuries. Today, the island is home to 19 original seaweed homes and one of them has just been put up for sale – a six-room cottage recently renovated with a whopping 35 tons of locally harvested eelgrass.

white home with large seaweed roof
white home with large seaweed roof

By the late 18th century, the island had 250 remaining homes with eelgrass roofs, which are credited for the long-lasting nature of the buildings. The roofs were typically layered on in thick piles, often reaching three feet of thickness. The technique created an impressively durable insulative envelope for the homes that has helped the buildings withstand the test of time.

living area with loveseat
dining table with chairs in large white room

Related: Seaweed-Clad House in Denmark Combines Natural Materials With 21st Century Building Techniques

For those doubting the logic of building with sea greenery, the natural resource is incredibly sustainable, as well as non-toxic and fireproof. It can be harvested by hand and cured by the sun and wind. And, as the Danish cottages have proven, its insulative properties are as durable as any contemporary insulation.

bedroom with large bed and white walls
dining room with long wooden table

The cottage, which is currently listed for $414,000, is a six-room home with an area of 1,076 square feet. Dating back to the 18th century, the home has been painstakingly restored to enhance its historic character. The original seaweed roof was replaced with 35 tons of seaweed locally harvested at the island’s “seaweed bank,” an initiative begun by the island for the sole purpose of restoring the remaining historic homes.

interior window with seaweed hanging down
white home with large seaweed roof

The extended farmhouse has six rooms tucked into the cottage’s traditional framework. The kitchen and living spaces receive an abundance of natural light. Rustic touches such as colorful farmhouse doors and exposed ceiling beams add an old-world charm to the interior. The cottage is located on large lot of land filled with ancient apple trees, and is just minutes away from a beautiful beach.

+ Adam Schnack

Via Treehugger

Photography by Per Nielsen via Adam Schnack

white home with large seaweed roof
white home with large seaweed roof
white home with large seaweed roof
white home with large seaweed roof
large living space with wooden flooring and white walls
kitchen with iron stove