Killwangen is an up-and-coming municipality in the canton of Aargau, located in the middle of the Limmat valley between Baden and Zurich. Baloise was able to acquire a 6,700 m2 building plot in Killwangen to build the MühliHof residential development, which features 89 apartments. In the middle of the plot is a listed farmhouse, which had to be preserved as well as being converted.
This presented the planners with the challenge of striking a good balance between preserving the existing listed structure and creating new apartments on the site. The aim was to emphasise the charm of the listed building while creating a harmonious overall feel in combination with the new residential buildings. In order to achieve the best possible outcome, Baloise conducted an architecture competition on a private basis with a project developer.
The winning project referenced the existing timber frame of the listed farmhouse with an open mullion-and-transom façade, generating a symbiosis that ensured the three new apartment buildings were perfectly designed and integrated from an architectural perspective.
Heating is currently one of the key considerations when planning a residential development. Extensive heating simulations were carried out when planning the MühliHof. At the preliminary project stage, a fossil gas heating system with an additional solar system as an energy source was the first choice. However, after reviewing the sustainability aspects and clarifying various issues, geothermal probes with a heat pump were chosen.
It is important to note that the investment costs for the heat-pump solution are significantly higher than for a gas heating system. The original calculation in 2020 foresaw an amortisation period of 21 years. Despite this, Baloise opted for the variant with geothermal probes and heat pumps for environmental reasons. In retrospect, this decision proved to be the correct one from both an environmental and economic perspective, as the price of gas doubled following the Russian invasion of Ukraine. The additional photovoltaic system on the roofs supports the operation of the heat pump and the charging stations in the underground garage. The Minergie certificate provides independent confirmation of the minimised environmental impact of the renovated farmhouse and the new buildings.
Meeting sustainability criteria was not just limited to insulation and heating – ensuring that the residential development is well served by public transport also makes an important contribution. The apartments are within a few minutes’ walk of the train station, which is served by the new Limmattalbahn (Zurich-Altstetten to Killwangen). Charging stations for private vehicles are also available in the underground garage, making it easier to switch to e-mobility.
The outstanding architectural design of the MühliHof development, its excellent transport connections, the commitment to sustainability and the affordable rents have proven to be a very attractive combination: all 89 flats were let within three to four months. This is also welcome news for Baloise policyholders, whose money has been invested in a worthwhile and forward-looking way so that insured benefits such as pensions can continue to be paid out in the future.