Seaweed pillows were used as cladding for this holiday house on the Danish island of Læsø by architecture studio Vandkunsten and non-profit organisation Realdania Byg. The Modern Seaweed House revisits the traditional construction method in Læsø, where for many centuries trees were scarce but seaweed has always been abundant on the beaches. At one stage there were hundreds of seaweed-clad houses on the island but now only around 20 remain, which prompted Realdania Byg to initiate a preservation project. The team enlisted Vandkunsten to design a new house that combines the traditional material with twenty-first century construction techniques. Seaweed is at the same time very old and 'present', because it is a very sustainable material. 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. It insulates as well as mineral insulation and is non-toxic and fireproof. It can last for up to 150 years.