From Intention to Implementation of Vertical Green: The Case of Ljubljana

This article examines the need and opportunities to implement vertical green in Ljubljana as a case of a medium-sized European city with a relatively green feel. Sustainability-oriented urban development supports the introduction of nature-based solutions in principle; however, there is a lack of vertical green as well as actual legislative and administrative support. Therefore, several methods were applied in the present study to link this idea to execution, starting with semi-structured interviews and a workshop for selected city officials. Legislative and formal backgrounds for implementation were then assessed. An inventory of green facades and other structures (e.g., noise barriers and retaining walls) in Ljubljana was prepared, and a geographic information system-based decision support system was developed to identify the potential areas in the city where additional green space elements would be most favourable for humans, the environment, and climate indicators. The results reveal a gap between opportunities and the actual situation. The general opinion that there is never too much green space in urban areas is confirmed by direct information from the city administration and strategic documents. There are many potential sites for implementation; however, this is hindered by ownership, management, and economic issues. The study concludes with some suggestions for following the best practices in other central European capitals, such as Vienna and Berlin.