Nienburg – Hans-Böckler-Straße
In Hans-Böckler-Straße in Nienburg/Weser, the future of living is taking shape. On behalf of GBN Wohnungsunternehmen GmbH, three uninsulated multi-family buildings from 1951 are being transformed into modern, climate-neutral living spaces through serial renovation. Fifty-four residential units, previously classified under building regulations as "Worst Performing Buildings," are becoming highly efficient KfW 55 energy-efficient houses with a NetZero balance in building operations. Minimally invasive, forward-looking, and offering a significant upgrade for the tenants.
Overview
Serial Renovation Using Prefabricated Facade Elements
To make the buildings future-proof, the project relies on the principle of serial renovation. The new building envelope consists of 35 cm thick, industrially prefabricated timber-frame modules. These factory-built modules already include highly efficient mineral fiber insulation, new sound insulation class 5 windows, and decentralized ventilation elements. The cladding, made of durable fiber cement with a light wood look, provides a modern appearance.
Roof & Photovoltaics
The pitched roof receives a new covering of anthracite-gray steel trapezoidal profiles. In addition to the installation of new skylights, the thermal envelope is completed by insulating the uppermost floor ceiling. Furthermore, a new PV system on the roof surfaces ensures sustainable, on-site power generation.
Basement & Building Services
Basement ceiling insulation, including perimeter insulation, ensures the thermal separation of the floors. Old exterior access points are solidly sealed and supplemented by new humidity-controlled exhaust fans for regulated ventilation. While heat continues to be supplied via the existing local district heating network, a new hydronic balancing optimizes the efficiency of the heating system.
Renovation Goals
- Energy Demand (-73%): The average final energy demand drops from approx. 168 kWh/m²a to around 45.5 kWh/m²a.
- NetZero Emissions: By drastically reducing demand and generating on-site green electricity, the buildings achieve the NetZero standard in operation.
- CO₂ Balance: Emissions drop from a previous approx. 79 tons per year to a negative balance of -20.9 tons CO₂eq/a.
D-G ➔ A
Energy Efficiency Class
Upgrading to KfW Efficiency House 55 standard
99.9 t
CO₂ Emissions Savings
Emissions reduction and PV credit lower CO2-Balance from 79 t to -20.9 t CO2eq/a
- 73 %
Energy Demand
Improvement of energy demand from 168 kWh/m²a to 45.5 kWh/m²a
“We were convinced by ecoworks’ holistic approach and the opportunity to save energy and reduce CO₂ emissions. Besides the significant energy savings, the economic advantages make serial energy retrofitting with ecoworks the clear choice. Thanks to available subsidies, the renovation costs are comparable to those of conventional renovations—despite achieving a higher energy efficiency standard and much shorter construction times.”
Maßnahmen im Überblick
Fassaden
Dach
Fenster
Balkone
Keller
Heizung
Hauseingänge
Energieversorgung
Leitungen
Gallery
