This four storey building is built using a very light and acoustically efficient building technique comprising structural components made of lightweight I-beams. The acoustical part of the building system is developed by Acouwood, together with Masonite Beams (www.masonitebeams.se) and Grönbo (www.gronbo.com) over a long period of time. The structural elements are composed to perform far better than average, and they are connected by specific predefined junctions isolating the floors and the walls between the residential units. The building is a proof (amongst some similar buildings) that it is possible to build environmentally friendly with very light components arriving in high sound insulation. It fulfils L´nT,w+CI,50-2500 ≤ 48 dB and DnT,w+C50-3150 ≥ 56 dB.