Wohnungsgenossenschaft Schwarzenberg eG is constructing an innovative building project in the Erzgebirge region. Despite existing vacancy rates in the Schwarzenberg area, south of Chemnitz, three apartment buildings are being developed which will boast a high degree of self-sufficiency thanks to a novel energy concept. This endeavour aims to generate benefits for tenants, the cooperative as landlord, and for the ecological balance.
The underlying energy concept is fully electric and solar-based. It integrates photovoltaic systems on the roofs and facades of the buildings, battery storage units, and highly efficient infrared heating. The planning and design of this specific solar architecture and energy concept were developed by Professor Dipl.-Ing. Timo Leukefeld from Freiberg and his Autarkie-Team.
Enrico Schaarschmidt, CEO of Wohnungsgenossenschaft Schwarzenberg eG, expressed a positive view of the approach after he and his fellow board member Michael Förster learned about the concept from energy expert Leukefeld. The conviction in this climate-friendly, fully electric, and de-technologised system led to the decision to construct three apartment buildings, each with seven residential units, based on this principle. These are the first apartment buildings in the Erzgebirge where the energy demand for heating, hot water preparation, and household electricity will be covered by approximately 60 per cent through self-generated solar power. The buildings are considered an addition to the Sonnenleithe residential area, aiming to make this district future-proof and more attractive.
All-inclusive rent and energy efficiency
A key feature of the new housing offering is the all-inclusive rent, which includes an energy flat rate guaranteed for an initial five years. This all-inclusive rate covers all residential and ancillary costs and aims to protect tenants from unpredictable expenses. The realisation of the all-inclusive rent is made possible by the anticipated high solar yield. Each building will be equipped with solar modules boasting a capacity of almost 80 kilowatts. Surplus electricity will be temporarily stored in battery storage units. The self-generated solar power is not only more cost-effective than externally sourced electricity but is also intended to ensure long-term predictable energy costs.
Professor Leukefeld and his team calculated the total energy costs for heating, hot water, household, and general electricity to be approximately 95 cents per rentable square metre per month. In comparison, these costs for similar, non-highly energy-self-sufficient new-build apartments typically range between 2.50 EUR and 4.00 EUR per square metre per month. The advantages of the all-inclusive rent also include the elimination of heating cost billing expenses and basic fees for electricity meters.
History and future direction of the cooperative
Wohnungsgenossenschaft Schwarzenberg eG looks back on a history that began with the founding of its original company in 1954. At that time, citizens contributed to reconstruction efforts. After its transformation in 1990, the company adapted to new requirements, refurbished apartments, and reduced vacancy rates from a former 27 per cent to currently about 12 to 14 per cent. The number of apartments decreased from almost 2,600 to around 1,800 units. Enrico Schaarschmidt highlighted that requirements have changed significantly and that the cooperative is intensively engaged in implementing climate goals by 2045. The de-technologisation approach of the Autarkie-Team is considered particularly effective in this regard, especially through the use of infrared heating instead of complex water-based systems. These maintenance-free units with a guaranteed lifespan of 30 years will be installed on the ceilings.
