Rapperswil Castle

At a glance

Project facts

Client

Municipality of Rapperswil-Jona

Project location

Rapperswil-Jona, Switzerland

Business area

BKW Building Solutions

BKW company involved

Werner Electro AG

Project status

completed

Year of construction

2024

Project type

Renovation

Technology area

Building technology

Service provider

Winter Electrical

Elektro Winter AG, part of the BKW Building Solutions network, specialises in electrical installations, building automation, communication technology and planning.

It plans and implements customised electrical engineering solutions for a wide range of requirements and supports its customers with comprehensive expertise from planning through to implementation.

Cable

Pipes

Working hours

Rapperswil Castle has been an important cultural site above the town of Rapperswil-Jona for around 800 years. As a landmark and cultural monument of the Lake Zurich region, the ancient castle attracts countless visitors and tourists every year. Elektro Winter, part of the BKW Building Solutions network, was responsible for renewing the electrical installations in the listed building. It was a project that Peter Baumgartner, Co-Managing Director of Elektro Winter, describes as “once in a lifetime”. “It is an honour to contribute to such an important building in our home town,” says Baumgartner proudly. In more than 10,000 working hours, he and his team succeeded in mastering the balancing act between progress and preservation within these historic walls. As part of the project “Conversion and restaging of the castle” the Rapperswil-based company carried out the complete modernisation of the electrical installations in the listed building over the course of around a year.

Electrician in yellow safety gear kneeling on a floor while working with cables in an unfinished interior

Challenge of heritage conservation

Throughout the entire construction process, the team placed the utmost importance on not altering the fabric of the building. In total, 450 lights and 325 sockets were installed, and more than 23,000 metres of cable and 7,500 metres of conduits were laid. Despite these impressive figures, many of the new installations are well hidden — the result of precise planning and creative solutions developed to preserve the building’s historic charm. For example, existing cable ducts were used and extended accordingly — no easy task when the number of cables increases but the space remains the same. Another challenge was dealing with historically valuable rooms such as the great Knights’ Hall or the bel étage. No new drilling was permitted here; only existing openings and cable routes could be used. “Working in a 13th-century building places special demands on planners and installers. Every single step has to be carefully thought through,” explains Roman Weber, project manager at Elektro Winter. Successful implementation is only possible through the highest level of precision and the ability to adapt specialist expertise to such an exceptional environment.

Customised solutions and energy efficiency

To meet the requirements of heritage protection, the team developed customised solutions. For example, battery-powered lights were installed for the emergency lighting in the exhibition area in order to avoid additional cable installations. Great care was also taken on the exterior façade. To lay the new cable ducts for the exterior lighting, small trenches were cut into the wall, which stonemasons then carefully restored. For sustainable and energy-efficient interior fittings, the team installed energy-saving LED lights and motion detectors that minimise electricity consumption. In addition, the new building automation system now enables flexible control of the lighting, further reducing energy consumption. These measures ensure sustainable use of the facilities and also increase comfort for visitors and staff. “With the restoration of the castle, we are contributing to the preservation of this important cultural asset and improving the energy efficiency of the infrastructure,” says Peter Baumgartner.

Team spirit as a success factor

The successful implementation of the project was only possible thanks to the well-coordinated collaboration of everyone involved. “It was a strong team effort. Everyone worked hand in hand to preserve this historic building for future generations,” says Roman Weber. Close and continuous coordination with Ghisleni Partner AG as the client’s representative was also important for the smooth progress of the project. As the client, the local municipality of Rapperswil-Jona was also significantly involved in the entire process.

A milestone for the region

The project shows how craftsmanship, heritage conservation, fire safety requirements and modern technology can be successfully combined to make historic buildings fit for the future. Through careful planning, we ensure the optimal functioning of the installed technology and thus actively contribute to a modern building infrastructure. In November 2024, the castle, which has been converted and newly staged at a cost of 17.5 million Swiss francs, will reopen – a flagship project for the Elektro Winter team and a milestone for the local municipality of Rapperswil.

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