An whole area designed to the Passive House standard in the German city of Heidelberg has shown its energy efficiency performance with flying colours, according to a recent assessment.
Bahnstadt is recognised as one of the most significant continuing Passive Projects, considering the scope of the project, that’s hardly unexpected; the scale of the regeneration is undoubtedly ambitious, even without the Passive House energy efficiency element.
Instead than focusing on a single structure, this effort aims to design an entire metropolitan district around energy efficiency. 116 hectares of land formerly used to house a freight train station now houses a mix of residential and business structures.
Several business buildings and institutes have opened in the region, as well as a kindergarten; a school, stores, a community centre, and a cinema complex are now being developed. There will be up to 12,000 people living and working in Bahnstadt if it is fully finished.
Recent measurements, according to the study, showed that the energy efficiency goals had been fully achieved. 14.9 kWh/(m2a) was the average consumption rate in 2014 for 1,260 housing units with a combined living space of more than 75,000m2.
Savings of up to 80% compared to traditional new building methods were realised. The statistically high number of residential projects developed by different property developers and architects strongly proves that a successful large-scale implementation of the Passive House Standard is conceivable, according to the entire report, which is now available online.
“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 have been tremendously successful,” said Søren Peper of the Passive House Institute (PHI), based in Darmstadt, Germany.
The project’s monitoring was overseen by Peper. Several apartment buildings, each with over a hundred units, were studied using monthly heat consumption metre readings as the foundation for the research. In the process, an average heating energy consumption of less than 15 kWh/(m2a) was measured.
A building’s heating demand is mathematically determined. There are other more variables that influence real consumption, including user behaviour and the weather. In the case of the present study, the PHI said it must be borne in mind that these measurements were largely made during the first year of operation, in which consumption is normally higher than in following years, due to labour linked to tenants moving in and necessary changes. Bahnstadt’s Passive House structures, on the other hand, are already “functioning faultlessly” despite these negative influences. Passive House Planning Package usage statistics indicated a high degree of consistency with demand (PHPP).
PHI director Dr. Wolfgang Feist adds, “The monitoring carried out in Heidelberg doesn’t just prove the reliability of calculations using the PHPP planning tool,” “When comparing the calculated and measured results, it’s clear that the Passive House Standard saves a significant amount of heating energy, and with it, costs as well. When it comes to Passive Houses, there is no so-called “performance gap” between expectations and reality.”