Students build sustainable and affordable wooden houses

By: Romy de Weert About a hundred students have worked on sustainable and affordable rental housing over the past six years. The three wooden houses are located in the Helmond district of Brandevoort, the Netherlands. With only the power of an aquarium pump, the house can be heated in the winter by heat generated in the summer. Students from Eindhoven University of Technology completed the first three sustainable wooden houses this week. A project they have been working on for six years. “It took so long because we wanted to make sustainable and, above all, affordable homes,” says Thomas van der Werff, who is involved in the project. “That is exactly the approach of CASA, which stands for comfortable, affordable, sustainable alternative.” Existing techniques Construction is responsible for 40 percent of global CO2 emissions. According to the students, it can be done a lot more sustainably with existing techniques. “We don't have to reinvent the wheel for that,” says Van der Werff. “We have used techniques that already exist, but are not yet widely used.” The concrete-free apartments - made of steel and recyclable wood - have a heat pump that works on direct current. The electricity is generated by solar panels on the roof. “But the real secret is under the house,” says Van der Werff. There is a water basin of 104 cubic meters. The heat that remains in the summer is extracted from the heat pump to heat the basin under the house. The heat stays there for months and can be used to heat the house in the winter months. No lost energy “Saving heat in a water basin is a technique that is used on farms,” says Van der Werff. “Why not try that with houses too?” Because the excess heat is stored in the summer, no energy is lost. This prevents a peak load on the electricity grid. The heating and various techniques come together in the heart of the house: the 'service core'. Team CASA designed the control technology itself to enable all systems to communicate and control each other. “In addition to being sustainable, we also made a smart home. It has demand-driven ventilation: sensors measure the air quality and temperature and ventilate when necessary.” Inside and outside made of sustainable materials It is not only the energy system that makes the CASA houses sustainable. “The houses are made of recyclable wood and the facade is made of bamboo,” says Van der Werff. The latter is CO2-neutral, requires little maintenance and is fire-resistant. “In addition, the house is modularly built,” says Van der Werff. This means that several 'blocks' can be attached to the house, so that you can easily expand and shrink the building. Team manager Antoine Post is himself the first resident of one of the CASA houses. The other two apartments are rented out by housing corporation Woonbedrijf. Antoine is happy with the result. “We experienced some delays, partly because of the longer delivery times of building materials, but our goal was to develop a sustainable, comfortable and affordable house. That worked!” The three CASA homes are intended for social rent, with prices for an area of ​​60 square meters being around 600 euros per month. There seems to be little in the way of rolling out sustainable and affordable homes throughout the Netherlands. “But we have to check whether the homes are suitable for every location,” says Van der Werff. “A water basin like this cannot be placed in every type of soil.” CASA 2.0 in the making According to Van der Werff, upscaling is necessary to keep it affordable. Team leader Post is therefore working with his start-up Integer Technologies on scaling up and commercializing the concept. He hopes to build a next version, the CASA 2.0.