Joint project "Building-integrated photovoltaics"


In view of the strategic potential of building-integrated photovoltaics (BIPV) and the significance of the renovation of the existing building stock for the energy turnaround, this project explored technological, spatial and socio-economic solutions to stimulate the integration of BIPV in urban renewal projects.




Background (completed research project)

Building-integrated photovoltaics (BIPV) can potentially provide a crucial response to achieve the Energy Strategy 2050 targets. Functioning both as envelope material and electricity generator, they can simultaneously reduce the use of fossil fuels and greenhouse gas (GHG) emissions, while providing savings in materials and electricity costs.

However, in spite of technological progress (continual efficiency gains, new technologies) and increasingly favourable economic conditions (reduction of costs, incentives), only a small part of this BIPV potential is currently exploited in Swiss urban areas (integration into façades or roofs).


In response to this situation, the project attempted to overcome the current obstacles, such as technological and economic parameters related to production, but also to construction constraints, law conditions, esthetical values and socio-cultural issues. This was done using a holistic approach – from industrial production to local implementation – with a view to the large-scale implementation of building-integrated photovoltaics (BIPV) in the context of urban renewal processes.


Due to the interdisciplinary nature of the joint project, the results cover a wide array of issues. They include:

  • the development of a new generation of photovoltaics (coloured and lightweight PV modules);
  • a set of architectural design strategies – both passive and active, illustrated through real case studies – to promote the integration of BIPV in urban renewal processes;
  • a holistic and robust multi-criteria assessment methodology to compare different intervention scenarios based on a qualitative and quantitative approach;
  • the determination of product-specific, adopter-specific and institutional facilitators, as well as financial and non-financial drivers for Swiss homeowners’ preferences;
  • the identification of relevant certifications, standards and regulations likely to facilitate the implementation of BIPV;
  • the implementation of targeted dissemination platforms (website, conferences, workshops, etc.) to accelerate the transfer to practice.


Relevance for research

  • The (highly applicable) results take the development of solar module technology beyond the state of the art;
  • Novel research approach in the field of design by relinking architectural and urban scales, and through the use of Building Information Modelling (BIM);
  • Contribution to the research on diffusion of innovation and on social communication and social contagion.

Relevance for practice

  • Preliminary test results are encouraging and may lead to the adoption of the developed technologies on the market;
  • Applications on real case studies that provide architects, PV installers and public authorities with a palette of solutions, based on a design concept underlined by an understanding of the specific features and needs of each building. It can be easily adapted, is reproducible in other contexts and supports the early integration of BIPV as a fully fledged construction material into the design process;
  • An improved understanding of consumer and investor preferences, a basis for an accelerated diffusion of BIPV.

Original title

ACTIVE INTERFACES - Holistic operational strategies crossing over obstacles for large-scale advanced PV integration into urban renewal processes

Principal Investigators

Leader of the joint project

  • Prof. Emmanuel Rey, Laboratoire d'architecture et technologies durables, EPF Lausanne

Deputy leader of the joint project

  • Dr. Sophie Lufkin, Laboratoire d'architecture et technologies durables EPF Lausanne


The joint project consists of five research projects

ACTIVE INTERFACES - Holistic strategy for PV adapted solutions embracing the key technological issues

  • Prof. Christophe Ballif, Institut de Microtechnique, EPFL Neuchâtel; Prof. Stephen Wittkopf, Dr. Laure-Emmanuelle Perret-Aebi, Prof. Roman Rudel

ACTIVE INTERFACES - Holistic strategy for BIPV adapted solutions in urban renewal design processes

  • Prof. Emmanuel Rey, Laboratoire d'architecture et technologies durables, EPF Lausanne; Prof. Marilyne Andersen, Prof. Jean-Philippe Bacher, Dr. Laure-Emmanuelle Perret-Aebi, Prof. Christophe Ballif

ACTIVE INTERFACES – Understanding consumer and investor preferences to overcome barriers for a large use of BIPV in the Swiss urban context

  • Prof. Rolf Wüstenhagen, Institut für Wirtschaft und Ökologie, Universität St. Gallen

ACTIVE INTERFACES - Holistic strategy to simplify standards, assessments and certifications for building integrated photovoltaics

  • Prof. Stephen Wittkopf, Technik & Architektur, Hochschule Luzern

ACTIVE INTERFACES - Holistic strategy to accelerate the transposition of advanced BIPV adapted solutions into real innovative practices

  • Prof. Jean-Philippe Bacher, Ecole d'ingénieurs et d'architectes, Fribourg; Prof. Emmanuel Rey, Dr. Laure-Emmanuelle Perret-Aebi, Prof. Christophe Ballif