Provide natural light to the Edison trading room, situated in an historic building in the centre of Milan in Foro Buonaparte. This was Zumtobel’s challenge as the company worked alongside architect Cristiana Cutrona of Revalue, together with lighting designer Consuline and electrical designer BRE Engineering.

The particular location and the objective to guarantee as constant and homogeneous a light throughout the day as possible were the driving force behind the company’s search for an innovative solution, while also taking into consideration the very structure of the building where the project was carried out.

The Edison trading room is open 24 hours a day, 365 days a year. It is located inside a historic building in Foro Buonaparte dominated by a beautiful glass dome in full art nouveau style. The aim of the project was to ensure that the offices would be illuminated after sunset, in a similar way to the sunlight that filters through during the day.

This was made possible by tunableWhite technology that enables to change the colour temperature of the light and the luminous intensity: Zumtobel's solution guarantees the 24-hour circadian rhythm imposed by natural light on our biological clock in offices. In the morning the light is warm, then becomes white and more intense, and finally returns to the tones of the beginning of the day.

A study of the particular structure of the building, dominated by the glass and iron dome, led to the use of two products by Zumtobel: TECTON and CRAFT. These industrial lights are usually for office use but their special versatility was crucial. The large window is supported by a metal structure on which it was not possible to carry out any operation or installation, and is also covered by another glass dome that protects it.

Centrally, the metal structure was used as a load-bearing structure in which the pre-electrified TECTON channel was housed, to which the TECTON C lamp was then attached with tunableWhite sources to provide variation in the white tone. In addition, the indirect light perimeter light groove was used to house the TECTON channel with the same lamp. TECTON is an extremely versatile product, with split technology lenses in a continuous row without optical interruptions. Its efficiency reaches 149 lm/W, with colour rendering of Ra 80. The split lens cuts the light in half and concentrates it in the two side parts. This reduces the central intensity. The luminaire is less dazzling, but does not sacrifice the photometric curve.

The other product used is CRAFT. The CRAFT with tunableWhite sources were placed within the two domes to illuminate the coloured dome and give the effect of natural light. Thanks to the coloured glass, this solution also creates the effect of particular plays of light that arise not only with natural light but also with artificial light.

The result of this operation was the fruit of rigorous and precise calculation and field tests to achieve the objective of providing the sensation that a light capable of replicating the natural sun would filter through the coloured dome in the evening and also in winter.