The GREEN DENSITY transdisciplinary research and teaching project focuses on the Waldstadt sector, a strip of forest bordering the city of Bern. This strategic site, likely to host new inhabitants and jobs close to public transport, is particularly adapted to explore urban densification issues. The objective is to experiment, compare and evaluate diverse possible urban forms for the development of such a site. The process includes the elaboration of six urban and architectural visions from students’ projects developed within Rey’s studio at Ecole polytechnique fédérale de Lausanne (EPFL) and their transdisciplinary multi-criteria assessment.