A new report confirms that Passive House design is delivering promised energy performance in the Bahnstadt district of Heidelberg, Germany. Proponents are particularly heartened with the average energy use intensity of 14.9 kilowatt-hours per square metre across 1,260 housing units given the number of different architects and developers involved in the project.

“The evaluation of the consumption data proves that the efforts made by the City of Heidelberg to design an entire city district to a high standard in terms of energy efficiency based on future-oriented specifications and corresponding quality assurance has been tremendously successful,” says Søren Peper of the Passive House Institute.

The 116-hectare Bahnstadt district is expected to ultimately accommodate 12,000 residents in a mixed-use infill community that was previously the site of a freight railway station and yard. With approximately 75,000 square metres (800,000 square feet) of housing now built and recently occupied, energy management specialists suggest average consumption could drop still further once tenants are well settled and the usual adjustments are made to operations.

In the meantime, they applaud the Passive House Standard and the accuracy of mathematically calculated energy demand projections using the Passing House Planning Package (PHPP).

“The much heard of ‘performance gap’ — a divergence between expectations and reality — does not exist with the Passive House Standard,” asserts Wolfgang Feist, director of the Passive House Institute.

Photo courtesy of Passive House Institute.