Author: Meta Berghauser-Pont, Professor, Chalmers University of Technology.

As cities across Europe respond to the pressures of rapid urbanization and the climate crisis, the urban planning toolbox is evolving. One critical advancement advocated by the Twin2Expand project is the transformation of the Evidence-Based Design and Planning (EBDP) framework — not only to evaluate social and economic impacts but to fully integrate social-ecological dimensions. This is central to achieving Sustainable Development Goal 11: making cities inclusive, safe, resilient, and sustainable.

Traditionally, EBDP has focused on measurable outcomes that tied densification and accessibility — increased walkability, reduced car dependency, improved air quality, and support for active lifestyles. However, the challenge is more complex: How do we build denser cities that are also greener, healthier, and more resilient? Addressing this question is at the heart of one of the research objectives of Twin2Expand.

Why Social-Ecological Integration Matters

The scientific insights compiled in Den byggda formens betydelse (“The Significance of Built Form”) present a compelling case for this evolution (Berghauser Pont et al 2024). The report argues for a broader planning lens, one that not only mitigates carbon emissions through compact urban design but also enhances cities’ adaptive capacity to climate change; one that can help stop the rapid decline of biodiversity and improve human health and wellbeing. This requires rethinking how we design and assess our urban environments — not just in terms of form and function but also in terms of biodiversity and human-nature interactions.

Cities must be seen as complex social-ecological systems, where built and green infrastructures co-exist and interact. For example, densification may offer transport and health benefits, but it can also reduce green space and limit biodiversity, which affects both microclimates and mental well-being.

The shift to a socially and ecologically informed EBDP is not just about adding more indicators. It’s about changing the narrative of what makes a city successful. It’s no longer enough to measure walkability or density. We must also consider biotope connectivity, microclimate regulation, mental health outcomes, and species diversity.

Twin2Expand aims to lead this transition by developing a next-generation planning framework that speaks the language of sustainability, health, and resilience — across species, systems, and scales.

From Evidence to Action

Effectively integrating ecological perspectives into urban planning requires more than new metrics — it requires new tools. A recent breakthrough by Twin2Expand partner SMoG (Spatial Morphology Group) at Chalmers University of Technology is the development of the Habitat Network Analysis Tool (HNAT). This open-source GIS-based plugin for QGIS enables planners to analyze habitat functionality and connectivity with a level of nuance that accounts for both ecological quality and dispersal barriers like buildings and traffic infrastructure.

HNAT was designed to support multi-species habitat network analyses. It calculates habitat functionality — a composite measure of both habitat quality and connectivity — by using advanced cost-distance algorithms that are sensitive to real urban obstacles. In a recent case study in Gothenburg, the tool accurately predicted amphibian habitats by factoring in green space quality, building heights, and traffic volumes (Kindvall et al 2024). The integration of these urban variables — missing in other tools — is important for urban planning and design. It allows to evaluate the trade-offs between urbanization and green space fragmentation.

By integrating centrality analysis (via the Place Syntax Tool) and landscape ecology, HNAT exemplifies the synergistic potential of combining urban morphology with ecological modeling.

What’s Next?

One of the exciting developments within Twin2Expand is the pioneering work to collect high-resolution data on urban bird diversity. In a recent study, the team developed a machine learning-based bird occurrence dataset based on over 10,000 hours of passive acoustic recordings, including 61 species, all systematically collected across 30 urban sites in Gothenburg (Eldesoky et al 2025).

Unlike typical citizen-science data, which often suffers from spatial and taxonomic bias, this dataset offers a systematic and fine-grained view of biodiversity in high-density areas. It opens new doors for evaluating how different urban morphologies — from compact low-rise to dense mid-rise environments — impact bird occupancy, richness, and seasonal activity.

Additionally, the second Twin2Expand Intensive Summer School 2025 on Evidence-Based Design & Planning, organized by the SURF Lab at the University of Cyprus in collaboration with UCL and Chalmers, will focus on Social-Ecological Urbanism. The Pedieos Linear Park in Nicosia will serve as case study and participants will explore interventions to enhance urban biodiversity and make the city greener, healthier, and more resilient. Applications are open for postgraduate students, early-career researchers, and urban professionals interested in spatial data science and evidence-based urban design. More information and application details can be found here.

These efforts illustrate how EBDP can evolve to incorporate ecological evidence, helping planners evaluate the biotic health of urban environments and make informed trade-offs between urban development and ecological functionality.

References:

• Berghauser Pont, M., L. Markus, A. T. Häll, Å. Gren, O. Kindvall (2024), Stadsform som stöd i urbana ekosystemtjänster, in Den byggda formens betydelse – Kunskap från forskning (2024:6), Stigsdotter, C. (eds), Boverket.
• Kindvall, O. et al. (2024). Predicting habitat functionality using habitat network models in urban planning. EPB: Urban Analytics and City Science. https://doi.org/10.1177/23998083241299165
• Eldesoky, A. et al. (2025). A bird species occurrence dataset from passive audio recordings across dense urban areas in Gothenburg, Sweden. Zenodo. https://doi.org/10.5281/zenodo.14629008

Disclaimer: The TWIN2EXPAND Project is funded by the European Union under grant agreement 101078890 and by the UKRI under grant numbers 10052856 and 10050784. Views and opinions expressed are those of the author(s) only and do not necessarily reflect those of the European Union or the European Research Executive Agency (REA). Neither the European Union nor the granting authority can be held responsible for them.