Revisiting Potsdamer Platz for Earth Day

With its pioneering low-energy design dating back to 1993, the Potsdamer Platz office buildings B4, B6 and residential building B8 for Daimler Benz AG set new sustainability benchmarks for the city of Berlin and beyond with predicted energy use intensity - if assessed according to the RIBA 2030 Climate Challenge, the buildings would meet the energy efficiency targets set for 2025.

The key objective was to design 3 buildings which could form a new European standard for the integration of a low energy design approach into a dense urban environment.

To achieve this, several passive design strategies were adopted such as opening up the courtyard to optimise daylight, improve passive solar gain in winter and enhance views to the park; using the 600m2 atrium to act as a thermal buffer, inducing natural ventilation and fine-tuning high performance facades to minimise conflicts between solar gain and daylight. Additionally, active systems and renewables such as PV panels which supply 60% of the energy required for domestic hot water for the top floors, and a district heating and cooling system, electricity by CHP plant and absorption chillers.

The modelled results of this project were impressive, with a predicted energy use intensity of 75 kWh/m2, estimated 50% lower energy consumption in the office buildings against benchmark, heating and cooling energy consumption 70% less than typical and embodied energy and CO2 emissions approximately 30% less than for a typical office building. To top it off, rainwater is collected across the overall Potsdamer Platz development roofs, saving approximately 20 million litres of drinking water each year and partially supplying the water areas in the public realm.