Cities worldwide are grappling with spatial constraints, particularly in rapidly growing urban areas. Rotterdam, as an aspiring sustainable city, faces similar challenges in balancing sustainability goals with limited space. This predicament extends to the underutilized rooftop spaces across the city. While initiatives like the “multifunction rooftop” program and “Rotterdam Rooftop Days” have made inroads, the issue of unused rooftops persists. The primary obstacle often cited is cost, but cost is a relative factor, dependent on the unique values held by different stakeholders, buildings, and neighbourhoods. Several approaches to activate these rooftops have emerged but often lack consideration for the perspectives of rooftop stakeholders.
This report introduces a novel strategy aimed at bridging the gap between municipal sustainability goals and the interests of rooftop stakeholders. The strategy leverages pattern language principles, providing a flexible framework for tailoring rooftop solutions to diverse scenarios. It not only assists stakeholders in conceptualizing rooftop designs but also aligns them with their values. To illustrate the strategy’s effectiveness, it is applied to a neighbourhood case study, wherein various rooftop types are designed in alignment with the proposed principles.

Steel is a widely used and very circular material, it can be recycled endlessly but that consumes a lot of energy, therefore, it is one of the most polluting industries in the world. Only 2% of this pollution is caused by production, the other 98% is caused by transportation during the production and recycling process. Half of the pollution caused by transport is by export en import of scrap metal from and to the port of Rotterdam to Asian and African countries, this also creates geo-dependency on non-EU countries for essential materials. We will use research through design approach, quantitative (LISA data and Openstreetmap data) and qualitative methods such as research on the steel cycle, scrapyard activities, stakeholders, and social and spatial environment. The main objective is to reduce the logistic effort by closing loops more locally by creating a network of bigger and smaller hubs and reinstalling makers- and manufacturing industries around the hubs in a symbiotic relationship. Hereby we aim to move metal recycling higher up in the R-ladder of circularity. Different socio-spatial, techno-economic and governmental strategies should make scrapyards more attractive and interesting locations and intertwine them more into the urban tissue. Hereford, they should attract makers- and manufacturing industries around the scrapyards to form a symbiosis in the use of metal and scrap metal. Simultaneously, this increases dutch manufacturing and increases the local economy and decreases geo-dependency. The end of the report provides a set of strategies that can be applied to scrapyards throughout the country to improve the locations and the network between them. This project can form a precedent, both for other bigger industrial or port cities in Europe, as well as for different material flows.