The Brief

The Police and Justice Centre (PJZ) in the centre of Zurich is a prison for temporarily detained persons as well as for pre-trial and security detainees. The impressive centre, consisting of the administration and prison sections and providing over 2,030 workstations, officially began operations in 2022.

The main contractor for the project HRS Real Estate AG, was briefed with making lighting control more efficient and integrating presence detectors throughout the building. Energy optimisation was an important criteria of the project, as was the quality of the products used. Tom Jakob, project manager at HRS, makes a simple calculation: “We will also be responsible for maintenance in the future. And if we use inexpensive or even cheap material here, it will fall back on us in the years to come.”

The Solution

In no other area can electricity be saved as much and as easily as in lighting. With efficient LED light sources, effective sensors and optimal daylighting, electricity consumption for lighting can be reduced by at least 50 percent – often with a gain in quality and comfort.

6,800 KNX components were installed and parameterised in the building, including LED luminaries and around 2,800 KNX presence detectors all supplied by Theben.

Because the selected devices have a square detection area despite their round shape, relatively few of them were needed, which also had an effect on the price quoted in the tender. An approximately 60-metre-long connecting corridor in the basement, contained just three detectors, which is very modest for this size area and achievable because of the large 360° square detection area of the Theben KNX presence detectors.


The PJZ building contains a gymnasium, large underground garages, kitchens, training rooms, meeting and cloakroom rooms, offices and much more. There is even a shooting cellar.  The complexity of tying all these areas together using devices that would exchange information across the KNX protocol presented a challenge for the contractors.

Construction quality and aesthetics presented a challenge for Theben. The brief stipulated that all elements on the ceilings were to be round, including the motion and presence detectors. Theben therefore produced many of the detectors especially for this project in the corresponding RAL colour for harmonious interior design.

The result

The Canton of Zurich has invested a lot of money in this sustainable project, which represents an excellent example of achieving building efficiency using KNX technology.

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