Greening urban roofscapes: exploring urban creative design potentials

The manipulation of surfaces has always been a constant for landscape architecture, transforming an element that usually bears a flat coding into an active, complex, mutating field. Planning the new post-urban condition when places become both dense and diverse it means thinking not only the spatial form of the cities, which is always subject to change, but to conceive its forms of aggregation on different semantic levels, extending the concepts of accessibility to green spaces as a quality standard. Many of the most promising ideas, in this regard, are the reformulation and recovery of the in-betweens: partitioning of open spaces and articulation of clustered activities, which don’t fit neatly together but producing new integrated land uses and patterns; including quirky, jerry-built adaptations or additions to existing architectural typologies. Urban rooftop functional design offers a promising option to enable creative inventiveness, urban land-use diversification and to deliver multiple nature-based solutions for the regeneration of ecosystem services. In this combination of challenges, urban agriculture (Sommariva 2014) and green roofs in urban Water-Energy-Food Ecosystem nexus may represent a promising field of investigation. Although the interest in Tactical Urbanism (Lydon & Garcia 2015) is taking up a relevant position of the contemporary architectural debate the paper traces a methodological position on the Open City model argued by Jane Jacobs and later by Richard Sennet (2018). The paper will offer a review of benefits and limitations of urban rooftop greening potentials in the creation of sustainable and resilient cities through the analysis of two case studies: New York’s Brooklyn Grange related to urban agriculture development potential, and Rotterdam’s Rooftop Catalogue by MVRDV to describe applied strategies of temporary creative reuse.