GreenTwins: Redefining urban greenery design for modern cities

Published on 21.09.2023

Written by Dr. Eeva Henna Helena Fabritius. Senior Research Fellow. FinEst Centre for Smart Cities / TalTech

The aims of the GreenTwins pilot project were twofold: to create a layer of dynamic digital vegetation for Urban Digital Twins, which was lagging the fast development of models for the built environment, and to develop ways to involve citizens into designing urban (green) areas.

Currently Tallinn, the European Green Capital of 2023, is building a new Digital Twin, where the dynamic layer of vegetation developed in the GreenTwins project is being taken into use to help planning city greenery.

GreenTwins was a 2.5-year long large pilot project of FinEst Centre for Smart Cities in 2021–2023.

Age-specific 3D models of Populus tremula produced by GreenTwins

Layer of vegetation for Urban Digital Twins (UDTs)

GreenTwins produced a layer of dynamic digital urban vegetation for Urban Digital Twins. The layer of vegetation includes algorithmically growing 3D models of plants that are typical to Northern European cities, and information about their growth patterns and seasonal changes in the local climatic conditions.

The vegetation layer also contains predefined vegetation sets for urban green areas, such as lawns, meadows and urban forests, which can be used to fill areas in urban plans. Dynamic vegetation models were a major novelty brought by the GreenTwins project.

Digital tools Virtual Green Planner (VGP) and Urban Tempo (UT)

GreenTwins produced two applications for participatory planning of urban (green) areas and for viewing the temporal and seasonal changes in urban vegetation.

Virtual Green Planner is a Unity game-engine based open-source 3D application for co-designing built and green areas. Virtual Green Planner was designed as a tool for active citizens to create alternative urban visions and discuss them.

Urban Tempo is a 3D-augmented reality application for realistic visualisations of built and green areas. Urban Tempo was designed as a tool for professionals and active citizens to view the temporal and seasonal changes in the urban vegetation.

GreenTwins trees in a green area plan created with Virtual Green Planner

GreenTwins created 3D models for pilot areas in Tallinn, Estonia, and in Helsinki, Finland, to demonstrate the benefits of Virtual Green Planner, Urban Tempo and the dynamic vegetation layer for urban participatory planning. The pilot area 3D models allow professionals and active citizens to view, for instance, how the visual appearance and ecosystem services of urban green areas will likely change over time and depending of the season.

Street-level view of trees along Tallinn's Falgi road in the GreenTwins Urban Tempo application

Physical space for participatory planning: Avalinn (Open City Centre)

To support citizen participation and the use of the novel digital tools, GreenTwins detailed the concept of Avalinn, a Smart City Planning Hub, which was recently opened in the city center of Tallinn at Kaarli pst 1.

Avalinn is a physical space equipped with state-of-the-art visualization technology for facilitating digitally aided participation and collaboration in urban planning. This physical space makes it possible to bring together various stakeholders—without concern for their level of digital literacy—into planning discussions and decision-making. Digital tools of the hub are seen as means for building common understanding of future change in the built environment.

Avalinn is the first space in Tallinn designed for digitally aided participation and collaboration in urban planning.

Avalinn hub at Kaarli pst. 1, Tallinn

Further development

The dynamic vegetation layer developed in the GreenTwins project is being made available also to other cities in a commercialization spin-off project Greentwin.ai & Herbarium supported by TalTech.

Additionally, FinEst Centre for Smart Cities is a partner in UrbanLIFEcircles, an EU LIFE project that aims at enhancing urban biodiversity in three European cities. In the project, the FinEst team will build upon the GreenTwins technologies and setup a digital twin to a biodiversity project site in Tartu, Estonia.

FinEst Centre for Smart Cities is also collaborating with GATE institute to produce a standardisation proposal for a CityGML Application Domain Extension for Vegetation.