Amt für Umwelt und Energie, Basel (Switzerland)
The new building for the Amt für Umwelt und Energie (Office for Environment and Energy) in Basel was completed in 2021 not far from the market square with its historic town hall. Right from the beginning, the client’s goal was to realise a “flagship project for sustainable construction” and a multiplier for other building schemes.
The slender and rectangular eight-storey building fits snugly between existing neighbouring buildings as a freestanding structure that responds in height to the surrounding context. The two upper storeys are set back to prevent overshadowing.
The energy concept for the building, which is constructed using a hybrid timber-concrete frame structure, is based on providing district heating and natural night-time cooling with thermal component activation as well as mechanical hygiene ventilation with closed-cavity windows. Combined with the photovoltaics integrated in the façade and the utilization of grey water, this has enabled the building to meet the requirements of the MINERGIE-A-ECO label.
The façade is characterised by a clearly defined grid with large-format window openings and narrow vertical ventilation sashes, which are also designed as corner windows in the southwest. More than two thirds of the opaque surfaces are designed as PV façades.
The façade concept ultimately realised underwent multiple design iterations. An approach using visible amber-coloured polycrystalline photovoltaic cells was initially pursued. Not yet satisfied with the result as an “urban solar dress”, the architectural practice further developed the concept by using 3D fused glass as the front panel. After experimenting
with different textures, they decided on a structure with a square grid and circular depressions in the surface. In order to accentuate the slightly translucent effect, especially when viewed from a distance, a PVB film with metallic reflected dots was additionally inserted between the fused glass and the PV cells. These dots are arranged in the surface
in three different degrees of density, graded between 5, 7.2 and 9 per cent, which rise from the first floor, initially each time over two storeys, to the seventh floor.
The result fascinates with its innovative reinterpretation of a glass/photovoltaic façade, in which historical architectural references are also recognisable. The chosen texture with its “deliberate unevenness” is reminiscent of Pierre Chareau’s façade with glass blocks at the Maison de Verre (1931) in Paris.
PV modules with an output of 167 kW are installed across a 1,141 m2 area using concealed fixings. This enables the building’s annual electricity requirement (approx. 45,000 kWh) to be covered, with surplus electricity fed into the grid.
In teamwork with specialist designers and manufacturers, the architects have succeeded in creating an extraordinary solution with this façade. In conjunction with a coherent building concept, their aesthetic and technical ambition has enabled the photovoltaics to present a completely new expression of solar technology – especially in close-up view – that also
succeeds in integrating the building into the urban context.
This project is the winner of the “Architecture Award Building-Integrated Solar Technology 2022“.
Project partners
Architect: jessenvollenweider architektur
Operator: Amt für Umwelt und Energie (AUE)
Owner: Einwohnergemeinde der Stadt Basel
Representant of the client: Bau- und Verkehrsdepartement des Kanton Basel Stadt
PV modules: Megasol Energie AG
Get an Overview of the series "Solar architecture at its best – Excellent projects from the Architecture Award Building Integrated Solar Technology 2022 introduced briefly“
About the Architecture Award Building Integrated Solar Technology
The “Architecture Award Building-Integrated Solar Technology“ was started in the year 2000 by the Solarenergieförderverein Bayern (Bavarian Association for the Promotion of Solar Energy) and held since then for the 9th time. The award is established as an international competition concerning the interface between architecture and solar energy. The prize honors exemplary contributions of planning and designing building-integrated solar systems.
In the last edition of the competition the jury singled out 15 projects from 121 entries, which we want to present in a series. The jury was unanimous in its positive assessment that even with very different building tasks, and in different environments, these projects show that photovoltaic modules and solar thermal collectors can be successfully integrated with equal ambition in terms of design and technology.