In Freiburg Dietenbach, a new district is being built for about 16,000 people. The heat will be supplied via a district heating network from a central heat generation plant. Large-scale heat pumps will be used, which will use groundwater and wastewater as a heat source, and in addition, the new development cooperation will be integrated into the WV West. 6 low-temperature heat pumps and 3 high-temperature heat pumps with the refrigerant ammonia are planned. In addition to the heat pumps, the groundwater heat exchangers, waste water heat exchangers, pressure maintenance, pumps, control cabinets, transformer stations and also small ancillary rooms such as storage, toilets and social rooms are also accommodated in the development cooperation. The media district heating, groundwater, sewage and electricity must be introduced into the building in development cooperation.

The building should be completed in mid-2025 so that plant construction can then begin, which will take about 1 year. The supply of heat from the new development cooperation is scheduled to begin in mid-2026.

The energy center is designed as a large machine hall. The heat pumps are installed in a separate room within the hall due to the toxic refrigerant ammonia. This room must also be equipped with storm ventilation in case of refrigerant leakage. For the installation of the pipelines within the hall, a second level is partly built on a second level in steel construction. The floor area for the building is 60 m x 30 m. The height of the building is 8 m. In the outdoor area, three buffer storage tanks with a volume of 150 m³ will be built next to the building, for which appropriate foundations will have to be built.

The façade is to be clad with wood. If necessary, there should be a photovoltaic system on the roof or partly also on the façade.

The scope of this call for proposals includes service phases 1-8 for, among other things:

•Civil engineering

• Shell construction, interior fittings and roof

• Painting and floor coating

• Windows and doors

• Building electrics (lights, sockets and emergency lighting, etc.)

• Drainage, water and sewage pipes

• Sanitary installation (toilet, sink, sink)

• Foundations of the energy center and buffer storage tank

• Steel construction in the energy center

• Lightning protection and grounding

•Fire protection

•Outdoor installation

• Access and parking spaces in front of the building

Optionally, other services can be offered in addition to this tender, e.g.

• Structural engineering / structural analysis

• surveying

• Geotechnical survey

• Schallschutzkonzept

• Fire protection concept

• Health and Safety Coordinator

This tender includes:

• Adoption of previous designs, also from the urban planning department of the city of Freiburg

• Coordination with the other trades and planning according to the service phases of the HOAI, basic determination up to object monitoring (HOAI service phases 1 to 8)