Puzzling: A BREEAM revitalized old office building has got a better energy rating than a German state of the art Passivhaus

A case study shows, that a BREEAM.de certified building is consuming only 28.5 kWh (sqm x a) primary energy, than a state of the art green high tech Passivhaus in Frankfurt Germany with 37 kWh (sqm a).A former German railway headquarter building in the North of Germany, Muenster, has been revitalized with a completely new building services structure to subdivide a former single tenant building in a multi-tenant building with multiple 400 sqm units. All mechanical and electrical services have been replaced and newly laid out, while the building of approx. 32.000 sqm was in full use.Newly implemented district heating ducts with electronically adjustable heating pumps, metered new radiators with individually adjustable thermostat valves led to energy savings.Together with new window frames with special gas filled glass panes led to an energy consumption which is below the primary energy consumption the politically promoted green Passivhaus system.Yet a state of the green art Passivhaus residential building in Frankfurt with 300 mm insulating walls and 800 mm insulating materials on the roof, with triple glazing windows and compulsory ventilation units with highly efficient energy recuperation of 82 % showed a primary energy consumption of 37 kWh (sqm a).The comparative case study will highlight some important facts that green energy does not start with the building technology, but with the technology of areal heating with the local power plant. The paper can get read on Friday or Saturday, since authors in private practice.