tanghus for Realdania | Vandkunsten

The Modern Seaweed House is built from prefabricated wooden cassettes that comprise the floor, façades and roof. Seaweed is featured as insulation within the cassettes themselves, as padding inside the acoustic ceiling draped in flax as well as for cladding both the façade and the roof. In contrast to the historic houses, on which the seaweed is stacked high on the roof in a tall, swelling, mushroom-like fashion, the Modern Seaweed House is more contemporary and tight in its expression. The visible seaweed has been stuffed into bolsters made of net knitted in strong wool. The bolsters are attached to the roof in overlapping runs and, in smaller scale, mounted on the façades using the same method. The house is designed by Vandkunsten firm of architects and erected 2012-2013. The prefabricated elements have been made at Green House in Kongerslev who have also been lead contractor on the construction and assembly of the house on Læsø. The padded ceiling elements have been made at Brian Liebeck in Frederiksberg on frames by Fab Lab in Næstved, while Praktisk Service in Stege along with trained thatcher Helle Raknes have been in charge of the production of the seaweed cladding. The seaweed comes from the two manufacturers on Bogø and Møn, respectively, who can provide the crucial seaweed of a decent quality after the seaweed plague destroyed most of the larger natural occurrences, including those south of Læsø, back in the 30s. The house is 100 square metres and is built for two families: Centrally located is a large family room with a kitchen, which is bounded to each side by a core containing technical installations as well as bathroom and toilet. Behind these cores, in each end of the house, there is a very large room that can be divided into two reasonable rooms – and above this, a bed loft is located allowing for more sleeping places. The house is heated via a high-efficiency heat pump placed in an adjacent shed that can also be used for storing the families' bikes, summer gear as well as a washing machine and a tumble dryer. The house is tight and effectively insulated and fitted with an efficient ventilation system with heat recovery. The effective insulation makes it possible in effect to live in the house year-round, or for instance maintain a constant temperature of minimum 10 degrees throughout the winter, making the house frost-free. The Modern Seaweed House is situated on the northern part of Læsø at 6 Tangborgvej next to two other significant houses: Realdania Byg's listed seaweed house, 'Kaline's House', which was restored and refurbished prior to its inauguration in 2012, and today rented as a summer house, and Hanne Kjærholm's summer house for the Rude family erected 1985-1987. The house is now to be sold at market price. Seaweed houses on Læsø The seaweed houses on Læsø are an exceptional part of the cultural heritage, domestically and globally. Only very few seaweed houses still exist: approximately twenty in total, out of which eleven are listed. One of these houses is 'Kaline's House', which Realdania Byg purchased and restored in 2012. At the time of acquisition, the house still had its original seaweed roof. The house was built more than 150 years ago and has 80 square metres of floor space. Kaline is a contraction of Karoline, which was the name of a previous inhabitant of the house. The house has now been carefully restored for posterity and remains as one of the few physical testimonies to the culture and the life, which have characterised the development on this beautiful island in northern Kattegat since the 1200s. 'Kaline's House' was the first leg of the Realdania Byg project 'Seaweed Houses on Læsø', while The Modern Seaweed House makes up the second. Since the first registration in the 70s, inhabitants of Læsø and friends of Læsø's unique building style have fought to save the last remaining seaweed houses. With support from the Danish Nature Agency, a pilot project in the middle of the 90s revived the old techniques at an old seaweed farm, but it suffered from a lack of proper local seaweed. Within the past years, however, good and healthy eelgrass has surfaced in the Baltic Sea. This has coincided with people of Læsø resuming the struggle to attract outside attention to the cause, and, in 2008, support from several foundations has ensured that two local farmers on the coasts of Møn and Bogø have been able to take up the trade of their ancestors with systematic collection and drying of eelgrass. Previously, eelgrass from this area was – among other usages – used in mattresses, in Denmark branded as Getama – an acronym for Gedsted Tang Madrasser (Gedsted Seaweed Mattresses). At the same time, support was given to another pilot project, this time with good seaweed laid on an entire roof of a smaller building. Thus, the work to retrieve skills and methods took a step further. As the first half of the third pilot project, the Danish Culture Agency has bought and restored one of the listed seaweed houses, 'Andrine's House' on 1 Alleen. The second half of pilot project number three is Realdania Byg's old seaweed house, 'Kaline's House', which was completed in the summer of 2012 following the full restoration and refurbishment. The Modern Seaweed House constitutes the fourth leg of the course.