“The whole densification discussion has been a hot topic here for quite some time now,” says Simon Frommenwiler of Basel-based architects Herlach, Hartmann, Frommenwiler (HHF), a 2010 Design Vanguard firm. “Basel continues to attract a skilled foreign workforce, but Swiss law forbids building on greenfield sites. Towers are disliked and generally prohibited by local planning rules. So how do you accommodate the population increase?” With this 15-unit housing project, located in the city’s St. Johann neighborhood, HHF sought to provide a possible answer. “You have this huge urban block that’s lined with apartment buildings around its perimeter, but is far emptier at its heart,” explains Frommenwiler. “Even with the legal requirement that only 50 percent of the site can be built upon, there’s huge potential to densify in the middle.”

The six-story residence (1) is independent of the perimeter buildings that surround it (top), though in some areas gets quite close to auxiliary structures and party walls (2). Photo © Laurian Ghinitoiu, click to enlarge.