Between integration and expression: BIPV façades in Basel – a comparative study

The global energy transition necessitates integrating sustainable technologies into the urban environment, positioning Building-Integrated Photovoltaics (BIPV) as a key element of contemporary façade design. Although the evolution of photovoltaic technologies has broadened architects’ vocabulary, implementing BIPV in European cities remains challenging due to contextual constraints, heritage protection, and the need for public acceptance. This study examines how distinct photovoltaic technologies influence the formal, material, and symbolic dimensions of façade design. A comparative case study was conducted on two public buildings in Basel, Switzerland: the Office for Environment and Energy and the Novartis Pavillon. Primary data were collected from on-site observations and photographic surveys (2025) and complemented by scientific and technical sources. Results show that BIPV façades can function simultaneously as energy systems and distinctly expressive architectural media. Sharing a focus on sustainability and innovation, the analysed cases represent contrasting approaches to BIPV design – one defined by architectural restraint and contextual harmony, the other by an expressive and interactive character. By juxtaposing these approaches, the paper highlights the expanding spectrum of solar architecture – from camouflage to expression, from integration to performativity – demonstrating how technological progress shapes both aesthetic meaning and symbolic communication.