Main content:
Refurbishment of old indoor baths in Heidelberg, Germany
Project participants:
Client: Kraus Immobilien
Architect: [ssv] architekten
Energy planner: solares bauen GmbH
Building data:
Building type: Bath
Location: Bergheimerstraße 45, 66115 Heidelberg
Gross floor area: 7.010 m²
Jury evaluation
"The municipal baths in the centre of Heidelberg, which had been in disuse for many years, were revived in a quality manner with a sophisticated utilisation concept. The baths now have the potential to become a popular amenity in the neighbourhood in the long-term. Thanks to well-designed additional structures, the existing structure with an NFA of 6,000 m² has taken on a contemporary raison d’être. The high-quality internal insulation in this old building works together well with the energy-efficient ventilation system. The heating uses wood and is CO2-neutral, while cooling is based on the local ground water and a gas-motor-driven absorption heat pump. Waste heat and the heat from food refrigeration are fed into the heating circuit. The high-class architecture harmonises well with the ambitious energy technology."
Project_characterisation
Building concept
The plans for this building foresaw the development of a market hall as an attractive, public mall which would be a meeting point and a place of interaction offering a wide variety of uses. Public entrances from the northern side from Bergheimer Strasse and from the square to the south will be provided.
A particular feature is the split-level arrangement of the main floors. The main pool level is around 2.40 m above ground level, while the basement area below is only 1.50 m below ground level. However, there are some very impressive rooms with large ceiling heights on this level, including the centrepiece, the boiler house, which is covered by a steel-and-glass structure.
The most important and, from the outside, most noticeable change is the integration of the southerly square as part of the entrance design. On the forecourt, which is currently used as a car park, an inviting area covered by an airy umbrella roof is to be created, which will provide the missing link between the public space and the very self-contained pool facilities.
Energy concept
For a start, the building fabric will be refurbished to a high standard. Triple glazing will be used in all areas with the exception of overhead glazing. External insulation with an insulation thickness of around 20 cm will be fitted to the exterior walls. The historical southerly facade will be insulated only on the inside to a thickness of 8 cm. The foundation slab will be extended and fitted with 16 cm of thermal insulation. Insulation thicknesses of 30 cm will be provided for the main roof.
The variety of uses of this building project offers a number of synergy effects from an energy-supply point of view. The large number of cooking areas (market stands and gastronomy kitchens) leads to a high demand for hot water. At the same time, the many internal heat sources mean that air-conditioning is also necessary for the gastronomy areas.
A gas-absorption heat pump provides hot water at temperatures of up to 65 °C as well as cold water at around 6 °C at the same time. The system achieves very high overall efficiencies due to the simultaneous use of heating and cooling. The remaining heating requirement is fully supplied from regenerative sources using a wood-burning system which can be run either with pellets or with woodchips.