Old buildings radiate a special charm and shape the cityscape of Hamburg in large parts. For their buyers, however, the pieces of jewellery often entail an energetic redevelopment. Efficiency and aesthetics have to be considered equally. The need for renovation of Germany's residential buildings is still massive. All the more so if the relevant energy and climate targets of the federal government are to be achieved: By 2050, the primary energy requirement in this area is to be reduced by 80%, and the renovation rate is to be doubled accordingly. This is a major task, as around 12 million of the 19 million residential buildings in the state were built before the first Heat Insulation Ordinance came into force at the end of the 1970s. Compared to new buildings, energy consumption per square metre is significantly higher here, 75% of which is accounted for by space heating. Conversely, this means great savings potential, which can be exploited by energetic refurbishment with a focus on thermal insulation.
Especially if the historical character of an old building is to be preserved, there is currently no more efficient product than Slentite.
In addition to the overriding environmental policy goals, the desire of owners and residents for a home with a feel-good climate that also satisfies their own aesthetic requirements is equally important. This was also the case for the new owner of a classic Hamburg red brick villa from the 1930s. It was clear from the start: When the house was purchased, it was an energy waster, and appropriate renovation measures were unavoidable. However, the regulations for the protection of historical monuments have considerably restricted the room for manoeuvre. Two areas in particular were critical - the basement, which was to be used in future not as a cellar but as a work and wellness floor, and the typical heating niches, which offered little space for insulation.
Since the familiar standard materials are relatively thick when applied with the appropriate thermal conductivity, the search for an alternative began. It was found in SLENTITE, BASF's new high-performance insulating material, which was used here for the first time in a pilot project. The aerogel panels based on polyurethane make it possible to insulate 25 to 50% thinner than the materials currently available on the market. This has paid off especially in the radiator niches. They shape the character of the house, which is why the classic ribbed radiators should neither be changed in position nor replaced by new ones. At the same time, insulation was most necessary at this point, as the masonry cross-section here was reduced from around 40 cm to just 11 cm - which ultimately meant heating to the outside. Only a maximum of 3 centimetres were available between the wall and the heating. Adhesive, slentite and plaster brought it together to just 2 centimetres, because the new high-performance material is used in slim 15 millimetres.
In the basement, the primary objective was to create a pleasant room climate in which people enjoy spending time - in addition to offices, there is also a small sports and wellness area. The requirements were easily formulated: Keep moisture out, heat in. Since SLENTITE not only has above-average insulation performance, but is also open to diffusion, the panels can both absorb and release moisture - the key to a good room atmosphere. The low material thickness was also convincing again here: Thanks to the slim application, the connection to the window reveals could be retained, so that the original character of the rooms was retained. The result convinces the owner: "It's obvious that the rooms have been given a completely different climate - without us having to compromise on space or design". After this initial success, further pilot projects with SLENTITE are currently in progress.
Photos: Jörg Autermann