In December 2019, the excavators drove into the former industrial site in Burgdorf and the new Fischermätteli district should soon come to life: the first apartments will be ready for occupancy in summer 2021. By 2024, ten apartment buildings with 169 inexpensive 2.5 to 5.5 room apartments and living spaces between 52 and 140 square meters are to be built in a total of three construction phases. Located in an idyllic location in the immediate vicinity of the forest, the buildings are grouped around a central meeting zone with five differently designed outdoor spaces.
Largest Minergie-A-Eco quarter made with Swiss wood
The Fischermätteli settlement will one day be the largest development in Switzerland that will not only be built with Swiss wood, but also meet the Minergie-A-Eco standard. This requires a positive energy balance and the expenditure for space and water heating, air renewal as well as for all electrical devices and lighting must be covered by renewable energies. The addition Eco focuses on the issues of health and building ecology and ensures a high level of living comfort. "Based on the positive experiences we have made so far, it was the only right decision for us in terms of ecology and sustainability to build the Fischermätteli in the Minergie-A-Eco standard," explains Bruno Kälin. He is Head of Marketing and a member of the management team at Strüby Konzept AG. The Strüby companies act both as builders and as full service providers (project development, architecture, engineering, production, implementation, customer service, customer service) and are also responsible for sales.
For the Fischermätteli, the client relies on spruce and silver fir from Swiss forests: “There is no better building material than wood. It is available locally, is growing steadily, is CO 2 -neutral, creates jobs in the region and ensures a good and healthy indoor climate, ”explains Kälin. The wood required for construction is bought directly from the forest owners, sawn, glued and processed in the region. Long transport routes are eliminated, which means that the embodied energy is very low.
Sophisticated energy concept
The client had put out a tender for the energy concept, which ewz won. The energy service company is responsible for planning, financing, realizing and operating the energy supply. The contracts run until December 2044 and begin in stages according to construction stages. The ewz Energy Solutions division has developed an integral concept for the Fischermätteli district, which, in addition to a sophisticated heat and power supply, also includes ancillary costs accounting that covers all media.
All buildings on the site are connected to an area heating network. The heart of the heat supply is the heating center with an output of 550 kW. Wood pellets from the region are used as energy sources. The quality management system of the working group QM wood heating plants ensures efficient heat production. The energy service provider finances and implements the heating center and the lines for heat distribution to the house. The client, on the other hand, builds the installations for the domestic hot water and for the fine distribution of heat in the houses. A heat pump instead of wood heating could not be considered due to the geological conditions at the site.
100 percent renewable solar power
In addition to the heat supply contracts, ewz agrees electricity supply contracts with the owners. These regulate the supply of electricity to a total of seven floor and site owners. Since the Minergie-A building standard requires 100 percent coverage with renewable electricity, a photovoltaic system is installed on every house roof. The ten plants in the final stage will have an output of 722 kWp. According to project manager Christian Rolli from ewz Energielösungen, the challenge was to achieve the required solar power yield and still have enough space on the roofs for maintenance and servicing of the photovoltaic modules. The solution was to choose monocrystalline high-performance modules with a higher degree of efficiency, which produce more yield in less space, but this is reflected in a higher price. Around 3200 m 2 of photovoltaic modules are installed on the site. If, for example, there is such a high overproduction during the summer holidays that not all of the electricity can be fed into the grid, production can be reduced.
The overall concept worked out by ewz Energielösungen convinced the client: "Our specifications for an ecological and economical solution that can be implemented and maintained holistically by one partner were implemented very well by ewz," says Bruno Kälin.
