## 1 Introduction
### Setting the Context  
The CLEVER Cities project (See the CLEVER Cities project page [[https://clevercities.eu/--accessed](https://clevercities.eu/--accessed)]([https://clevercities.eu/--accessed](https://clevercities.eu/--accessed)) on 18 November 2022) has been active since 2018, experimenting with the implementation of Nature-Based Solutions (NBS) in three front-runner cities and six fellow cities. Among other H2020-funded projects (e.g., proGIreg, UNaLab), CLEVER Cities aims at implementing NBS by adopting a co-creation approach as an integral part of the project development, leading to the establishment of collaborative governance frameworks [7]. The specific focus of CLEVER Cities lies in tackling the social inclusivity and cohesion dimensions of NBS implementation within the existing urban context. The intervention areas are located in socially disadvantaged neighborhoods experiencing various forms of marginalization, and NBS implementation is expected to produce positive impacts in these areas. Two main levels of decision making are recognized. The first level corresponds to the Urban Innovation Partnership (UIP), describing an overarching network of actors coordinating the overall activities of the CLEVER Cities project in each of the three cities. The second is the CLEVER Action Labs (CALs), which is a nested sub-structure of the UIP that focuses on specific spatial areas with stakeholder groups that were either similar to the UIP, partially overlapped that of the UIP, or that had some common stakeholders. The CAL represents the ULL within the CLEVER Cities project nomenclature. As co-creation processes evolved, the need to identify, strengthen and build stakeholder partnerships in order to develop community-based and validated Urban Living Labs became the initial driver towards the creation of the first collaborative networks in each of the cities: London, Milan, and Hamburg. The way each partner city started the process of connecting with stakeholders led the projects down specific organizational pathways that had to bridge the working relationship between UIPs and CALs. This eventually led to functioning governance structures that, in general, could not be classified as simple, one-level networks. The changes in network relationships in the UIPs and Living Labs were able to help bring transformational learning, relational thinking, and transparency needed for the ULLs to advance their goals. Networks can adopt different strategies which either alter the internal workings of the organization or strive to maintain some independence and form intra-network relationships that play a role in developing both deep and wide community engagement. A range of network characteristics has been observed, and it was necessary to expand the list of reference typologies not only to describe subtle variations in nodal relationships but also to develop a full spectrum from highly top-down networks to horizontally grouped networks to understand how governance structures move up and down this spectrum. As the project progressed, adaptations and changes occurred, and as each iteration occurred, new governance constellations evolved, but there were some clear patterns in the ULLS of all three cities. It is hoped that these can offer insights into possible, successful strategies for the development of co-governance structures in other contexts. In the case of the Urban Innovation Partnership in London led by Peabody (a London-based housing association) in partnership with the Greater London Authority (GLA), contextual issues specific to the South Thamesmead region set the way forward for initial engagement, co-creation, and the eventual governance structures that emerged. One key factor was the limited level of existing social structures encountered, coupled with consultation fatigue and general distrust towards top-down projects. Some limited trials with community-led development have begun to revert this general picture, and together with CLEVER Cities, we now see the growth of a burgeoning culture of participation in the area.