Prefabricated Seaweed Thatch Panels

Imagine a building material that is rot resistant, fire resistant, non-toxic, insulates comparably with mineral wool, and can be used to create carbon negative buildings. Sounds amazing, right? Actually, this material has been used for centuries already around the world- until we forgot how to use it. It’s called eelgrass, and is a type of seagrass.

By combining the traditional seaweed thatching technique from Læsø, with prefabrication, these convenient panels install easily on roofs and facades. In theory, they can provide supplementary insulation and act as a type of green roofing material by supporting local plant life. In 2019, the Seaweed Pavilion was built with these panels to test them, and to encourage the general public to experience eelgrass as a building material.


Eelgrass, seaweed, seagrass.


Kathryn Larsen


Viking-style seaweed thatch updated into prefab panelling (Article)
The Seaweed Pavilion: A Building Experiment (Video)


Boligfondens Kuben Spirekasse

Photo credits

Kel Hudson