Recycling House in Hanover
- Barbara Zettel
The single family home in a new development in Hanover is a striking sight: Between the uniformly rendered neighbouring houses, the compact building volume surprises observers most of all due to its facade. It is structured into dark horizontal bands consisting of black fibre cement panels and profiled glass. The origin of these components the three-storey solid timber structure is clad in could hardly be more unusual: 90 % of them belonged to other completed projects. The architects of cityförster and the client, a real estate and construction firm, jointly developed the experimental dwelling in order to test different aspects of circular economy in a real-life, living lab scenario. The influence of recycling architecture becomes most apparent within the climate balance. The building sector consumes more than half of globally available resources and is responsible for more than 50 % of global waste generation. With an assumed life cycle of 50 years the share of embodied energy that is necessary to create building materials, erect a building, maintain it and demolish it is between 40 % and 60 % of the total energy demand. The use of recycled construction materials conserves resources and energy. Yet the planners set their goals even higher. Instead of merely using off-the-shelf recycling products in a cyclical manner, they also employed pre-used construction components. It took three years to plan this unusual project, requiring a high degree of flexibility. And it was often necessary to respond spontaneously as soon as a component became available. As a result, detail planning took place while construction was under way. The challenge was that no norms or permits for pre-used components existed. The original idea was to assemble pre-used steel parts of a storage hall to build the shell. The planners abandoned this idea since every component would have required an individual permit based on its actual load-bearing capacity. Instead, they opted for a solid timber construction. The stacked elements contain no glue and are connected by beech dowels. The components permit disassembly and can be returned to the material cycle after use has expired without any loss in quality. The recessed entrance area is clad in larch wood slats reclaimed from the former sauna benches of a sports centre. The ground floor features a living and kitchen area, where the mix of different materials creates a cozy atmosphere. The terrazzo floor was cast in one piece. It contains brick chips and brick fragments that harmonize with the exposed masonry brick of the partition walls. The bricks were reclaimed from an old barn. Made of historic oak beams, the stacked timber wall that borders the staircase attracts attention. It contrasts with the new solid timber ceilings. Their surfaces were left exposed. On the top floor a bright corridor leads to the bedrooms. Decorative particle board provided by a trade fair construction company was used for built-in closets and as cladding of the lightweight partition walls. In order to meet current standards, the building services, sanitary, heating and ventilation equipment are completely new. Most service lines remain unconcealed to make sure that they can be easily reclaimed.
