ARTIFICIAL LIGHT
The selection of appropriate light sources is determined by a wide range of qualities and characteristics such as color representation, efficiency, lifespan of the light source, and maintenance costs.
To arrive at a reference point for what can be expected in terms of efficiency, we compared various lighting technologies offering the same light intensity and a constant output in Watts per surface. If a heat flow density of 25 W/m² is released into a gallery space of 100 square meters with a ceiling height of 5 metres, the illumination level of the wall surfaces with artificial light amounts to between 35% and 100%. This is solely dependent on the lighting technology. A combination of fluorescent lights with high colour quality and metal halide lamps facilitates an lighting level of 50% on the wall surfaces. A solution using only metal vapour lamps would reach 100%.
The value of 25 W/m² given above indicates the maximum consumption, whereas the value when installed can be much higher. The amount of light can vary according to needs, and also according to the demands of conservation.

ENERGY SUPPLY
The energy supply is guaranteed by a geothermal probe and heat pump or, for cooling purposes, using direct cooling via the geothermal probe.
The number of geothermal probes is determined by the total cooling requirements. The heat provided by the geothermal probes is available all-year-round, either for extracting geothermal heat or returning excess heat.
To obtain an optimum coefficient of performance when operating the heat pumps, they are operated at low system temperatures (30–36 °C). The compressors used are turbocompressors with magnetic bearings. The target annual COP for heat pump operation is over 6.5. With two heat pumps, each providing 67% of total output, optimum operational security is guaranteed.
For domestic hot water provision, district heating from the university’s district heating grid is used.
This straightforward concept forms the foundation of simple, secure operation.
The 1000 m² photovoltaic system installed above the light shaft on the roof supplies part of the electricity requirement.

PASSIVE REGULATION OF INTERIOR SPACE
It is intended that the storage mass of the building should be as large as possible. A self-regulating effect, among other things, is achieved by means of an underfloor heating system at a low temperature level (20–30°C) and a ceiling cooling system at a level of 18–20 °C. However, the flow rate in these systems is mechanically regulated.

STRUCTURAL CONCEPT
The structural concept for the extension to the Art Museum in Zurich consists of a three-dimensional structure, consisting of direct and excentric bearing walls and floors. The lateral forces generated by the excentricity are transferred into the floors and walls. The dimensions of the bearing walls are based on the theory of stress fields.
The stresses on the floors are dissipated directly downwards or, if suspended from above, through the bearing walls. The floors are partly prestressed and the foundation is tied to the ground with bolts.