Neighbourhood with old buildings with passive house standard
(Baden-Württemberg)

Source: solares bauen GmbH
The residential neighbourhood Blaue Heimat is located in the Handschuhsheim urban district in Heidelberg (pop. approx. 145,000). A total of 155 apartments and ten semi-detached houses were built between 1927 and 1951. Over time, the entire building stock, notably the building services, became obsolete. The insufficient heat insulation led to high running costs, the insufficient fire and noise insulation led to further limits in the housing quality. Because of the partial lack of bathrooms and the distribution of space, the layout of the apartments no longer corresponded to today's needs.

Source: solares bauen GmbH
The aims of the redevelopment, which started in August 2004, were to remove the structural and space-related drawbacks and the creation of a climate-neutral building complex without use-related (CO2) emissions. The focus of the energetic redevelopment was the toughening of the building shell, replacement of the building technology with energy-saving components and the installation of a ventilation system with heat recovery. Layouts were changed in the buildings, and the living space was expanded with comfort-forming elements (e.g. balcony). The building section (55 units) was completed in October 2005.
For the redevelopment, the partly empty buildings were completely vacated by the landlords’ relocation management. The tenants had the opportunity to return to the complex's apartments after the redevelopment. After redevelopment, the gross rent was based on the rent level for the urban district. The basic rent is higher than for comparable living space, but the lower running costs have a permanent, cost-reducing effect. Since the redevelopment, there is a great demand for living space in the Blaue Heimat according to the housing company. The tenants assess the quality of life there very positively.
The planned energy savings were achieved in the first two years after the modernisation of the building. The primary energy use (heating and electricity) fell from 438 kWh/m² per year to just 100 kWh/m² per year. The annual heating requirement, in particular, was reduced as a result of the measures taken by 87% to around 21 kWh/m² per year. However, excessive ventilation heating loss has been identified because tenants continue to open the windows despite the technical ventilation system. This is why the housing company offers training and events regarding the building technology. This provides the tenants with information about the features of their apartments and the consequences of their actions. Heat loss has been restricted as a result. Apart from the behaviour regarding apartment ventilation, the building technology does not place any particular requirements on the residents.
The entire building complex has been certified as a "ZeroHaus" (Zero Building) in a multi-stage certification process. The process is based on the evaluation of the overall consideration of the energy saving directive. Based on this, it demands even more challenging limits. Apart from observing the energy limits, the certification includes monitoring the planning and redevelopment measures.
| Year | Event |
|---|---|
| 2003/04 | Planning for the redevelopment measures |
| 2004 | Start of comprehensive modernisation work |
| 2005 | Completion of the modernisation work |
| 2005 | Provisional certification as a ZeroHAUS |
| 2006 | Interim audit for ZeroHAUS certification |
| 2007 | Final certification as a ZeroHAUS |

Source: GGH Heidelberg

Source: solares bauen GmbH

Source: solares bauen GmbH
As a result of the interaction of building insulation, innovative building technology and other energy-saving possibilities, the annual heating energy requirement fell to just approx. 21 kwh/m². This is considerably below the threshold for new buildings according to the energy saving directive. Moreover, the need for (system-related) electricity has been reduced by around 60% to approx. 50 kWh/m² per year. The remaining energy required is provided by a wind power provider from regenerative sources. Overall, there is CO2 neutrality Overall, a groundbreaking project for saving energy and reducing CO2 for multi-storey old buildings has been realised.
The project location can be directly translated into Google-maps. Project in Google-Maps
The projekt site ist to be found at postal code: 69121 - town: Heidelberg - street: Karl-Philipp-Fohr-Straße 4-10.
Record inserted on 24.06.2009 by the Federal Institute for Research on Building, Urban Affairs and Spatial Development (BBSR) within the Federal Office for Building and Regional Planning (BBR).
Last update: 29.10.2009