The tradition of covering dwellings with dried seaweed has existed in Lesø for over 150 years: the island has always lacked wood, while the seaweed on its beaches has never been transferred. A century ago, there were at least several hundred houses built with algae on Lesio, but today there are no more than 20 such structures. A few years ago, the non-profit organization Realdania Byg drew attention to this, which began a large-scale project to preserve unique buildings and revive technology. the use of algae in private construction. One of the first projects implemented under this program was a two-family country house, the project of which was commissioned by Realdania Byg to the Vandkunsten architectural bureau.
The frame of the house, the total area of which is 100 m2, is made of natural wood, and the floors, walls and roof are assembled from prefabricated wooden cassette modules. From the inside, these cassettes are filled with dried seaweed - a material that has excellent heat and sound insulation properties, is absolutely non-toxic, and is also not afraid of fire, parasites and decay. Algae are also actively used as a facing material: it is with them that facades and a high gable roof are trimmed. In order to give them a more expressive texture, the architects collect the algae in narrow oblong mesh bags and the resulting "rolls" are then fixed horizontally on wooden surfaces.
The central core here is a “family room” common for both apartments with a kitchen flanked by risers with communications and bathrooms. Behind them, at opposite ends of the house, there is a room for a family, which, if desired, can be divided into two parts. Additional sleeping places can be arranged on the mezzanine floor.
A house made of algae can rightfully be called "green" due not only to the environmentally friendly materials from which it is built, but also to the engineering systems used in it. In particular, it uses heat recovery ventilation and heats the house with highly efficient heat pumps located in a small utility shed next door, where residents can also house a laundry or store bicycles.
