The Challenge:
Two residential buildings in Berlin, built in 1954 and comprising 21 apartments (1,043 m²), display the typical challenges of their era: high energy losses (originally rated Energy Efficiency Class F), an aging building fabric, and rising utility costs. A scenario that affects many post-war neighborhoods. The goal is to significantly improve energy performance—from Class F to Class B—through serial renovation, while also enhancing living comfort and ensuring the buildings’ long-term resilience.

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The Approach:
At the core of the project is a serial renovation, beginning with the creation of a new, highly insulated building envelope. This includes prefabricated facade elements with modern windows, as well as extensive insulation of the roof and basement ceiling. A photovoltaic system is being installed to enable on-site electricity generation. The energy concept is further strengthened by decentralized ventilation units with heat recovery and the replacement of all radiator valves to optimize heating. Existing district heating and centralized hot water supply are retained as an efficient foundation.

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The Result:
Once completed, the project is set to achieve a substantial improvement in energy efficiency—from Class F to Class B—reducing final energy consumption by more than 63%. CO₂ emissions will be significantly lowered through the combination of district heating and photovoltaics. The serial renovation approach ensures fast, cost-efficient implementation with minimal disruption for residents. The outcome will be a modern, energy-efficient living environment that creates lasting value for tenants, property owners, and the environment alike.