Synergies and trade-offs of nature-inclusive architecture in dense cities: between human health and urban biodiversity

1 Introduction

As global urbanization intensifies, high-density cities increasingly embrace vertical development to accommodate population growth while limiting urban sprawl. Yet verticalization often comes at the expense of direct access to natural environments, leading to reduced opportunities for human-nature interaction and declining urban biodiversity. Biophilic design frames architecture as an interface for integrating natural elements, processes, and experiences into the built environment, with a primary concern for human health and wellbeing (Kellert, 2008; Zhong et al., 2022). It differs from green architecture, which is often evaluated through energy, material, and life-cycle environmental performance (Ragheb et al., 2016). Nature-inclusive cities focus more broadly on incorporating biodiversity goals into urban development, district planning, green-blue infrastructure, and real estate projects (Mattijssen et al., 2023; Monti, 2019). Since urban residents spend nearly 90% of their time indoors (Ma et al., 2024), buildings become critical spaces for reconfiguring human-nature relationships. Building-integrated green spaces can also serve as vertically distributed ecological nodes, supplementing limited ground-level greenery and providing habitats for urban flora and fauna. This article therefore explores nature-inclusive architecture, which integrates living organisms, habitat conditions, and ecological processes into buildings to promote human health and urban biodiversity.

In dense cities, nature-inclusive architecture is often materialized through three-dimensional green spaces (e.g., sky terraces, green balconies, and vertical gardens), representing a shift from horizontal greening to volumetric and vertically distributed ecological systems (Zhong et al., 2026). However, optimistic narratives of nature-inclusive architecture often mask the uneven performance in practice; despite the potential for mutual benefits between human wellbeing and non-human habitat needs, this is by no means guaranteed. Integrating nature into architecture requires careful consideration of trade-offs, such as prioritizing human demands for comfort, safety, and ease of maintenance, which can sometimes conflict with the “chaotic” nature of functional ecosystems.

This article critically examines the synergies and trade-offs of nature-inclusive architecture in dense cities, emphasizing the delicate considerations for multi-species symbiosis. It argues that not all types of green spaces yield the same effects. By categorizing three-dimensional green spaces according to the spatial verticality (sky, elevated, and ground) and openness (open, semi-open, and closed), the discussion highlights the differentiated strengths and limitations of varied types in supporting human health and urban biodiversity. This typological perspective underscores the need to move beyond generic applications of vertical greening and toward more context-sensitive and performance-oriented design approaches that acknowledge both the potentials and constraints of nature-inclusive architecture.

2 Synergies: co-benefits between health and biodiversity

2.1 Microhabitats and nature connectedness

Nature-inclusive architecture can create urban microhabitats by providing nesting, feeding, or resting spaces for birds, arthropods, and other organisms (Wooster et al., 2022). A ten-year assessment of an intensive green roof with a bioreceptive façade at a French school recorded 345 species (including 207 plants, 100 invertebrates, 20 birds, and a few reptiles and bats), showcasing biodiversity levels comparable to nearby parks (Lewandowski et al., 2026). Distributed among buildings, various green spaces can form ecological networks for wildlife while bringing urban dwellers into closer contact with other species (Fuller et al., 2007). People who regularly watched and fed garden birds reported feeling more relaxed and connected to nature (Cox and Gaston, 2016). Observing pollinators, seasonal changes of plants or bird activities in rooftop gardens, balconies, or other spaces can strengthen residents' nature connectedness and emotional attachment. A study also found that 2 weeks of nature intervention during the winter can enhance positive affect, hope, and nature connectedness (Passmore et al., 2022). In this way, ecological habitat provision and human psychological connection to nature can become mutually reinforcing rather than isolated.

2.2 Biodiversity and environmental comfort

Nature-inclusive architecture links biodiversity and environmental comfort because plant traits influence habitat provision, shading, evapotranspiration, air filtration, and sound attenuation. A survey of vertical greenery systems in Singapore shows that vegetated walls support greater animal diversity than bare walls, while also cooling building surfaces during the day and providing insulation at night (Hecht et al., 2025). On an extensive green roof in Rome, native Mediterranean perennials outperformed Sedum album in terms of plant health, coverage, and flowering; meanwhile, the temperature in the planted area was 2.9–4.4 °C lower than in the adjacent concrete area (Bellini et al., 2025). A comparative roof study also identified vegetation cover, plant assemblage, season, and urban location as determinants of thermal performance (Robbiati et al., 2024). Vegetation can remove airborne pollutants, although dense planting may restrict airflow in poorly ventilated settings and affect air-quality outcomes (Chen et al., 2025). On extensive green roofs, vegetation and substrate together reduced noise by 1–4 dBA, with performance influenced by plant cover, substrate, moisture, and gaps in the planting (Lu et al., 2025). Hence, biodiversity and environmental comfort can be jointly enhanced when plant traits and system configurations are matched to local climate, water availability, substrate conditions, target species, and ecological goals.

2.3 Species richness and experiential quality

The synergy arises when nature-inclusive architecture not only provides vegetation cover but also supports greater species diversity. Research indicates that environments featuring diverse elements such as plants, birds, and butterflies are more effective at boosting perceived restorativeness and subjective vitality (Hung, 2025). Perceived bird biodiversity contributed to emotional wellbeing through perceived restorativeness during nature walks (Marselle et al., 2016). Office workers also rated living roofs more favorably than bare concrete roofs, with tall, green, grassy, and flowering vegetation receiving the highest preference and restoration ratings (Lee et al., 2014). Moreover, biodiversity in nature-inclusive architecture fosters richer sensory experiences, such as birdsong, the rustling of leaves, and floral scents, expanding beyond mere ornamental landscaping. Multisensory biophilic environments have the potential to enhance residents' satisfaction and cognitive performance, assisting in stress reduction (Aristizabal et al., 2021). Therefore, increasing species richness can make spaces appear more vibrant, attractive, and restorative, thereby enhancing the overall experiential quality of natural environments.

2.4 Environmental preferences and physical activity

Environmental preferences influence whether the spaces are entered, used, and revisited, as well as how people interact with nature. Nature-inclusive architecture that provides “lush,” species-rich environments is more effective in encouraging people to participate in physical activities, such as walking or exploration (Bell et al., 2021; Markevych et al., 2017). In Barcelona, overall green-space quality was associated with greater use and moderate-to-vigorous physical activity, with bird biodiversity and amenities relevant to the outcomes (Knobel et al., 2021). At a Memory Clinic in Malmö, a rooftop garden featuring a visible entrance, looped path, and central lawn supported spontaneous walks, outdoor breaks, and organized exercise (Oher et al., 2025). Biodiversity can therefore support active engagement when it is combined with accessible routes, suitable amenities, safety, and spatial configurations accommodating different activities. By harmonizing ecological richness with human preference, nature-inclusive architecture functions as a proactive intervention that simultaneously promotes health and biodiversity.

2.5 Social cohesion and environmental stewardship

Accessible shared green spaces can support social wellbeing when they enable interaction and collective care. A survey of 1,249 Singapore residents found that frequent garden visits and stronger experiential connections to nature were associated with a sense of belonging and greater social cohesion (Oh et al., 2022). Public-access community gardens in Berlin also generated environmental learning and a sense of place, although outcomes depended on participation structures and the balance between gardening and social objectives (Bendt et al., 2013). Collaborative planting, observation, and maintenance can make biodiversity visible and socially valued, cultivating environmental stewardship (Fink, 2016). Such stewardship contributes to protecting local biodiversity while transforming human social activities into a vital force for ecosystem conservation. Hence, nature-inclusive architecture holds the potential to become a socio-ecological infrastructure that fosters the health and wellbeing of humankind and other species.

3 Trade-offs: constraints and contradictions of nature-inclusive architecture

3.1 Access to nature vs. hygiene and safety

In nature-inclusive architecture, trade-offs exist between the benefits derived from exposure to “nature” and the risks of “causing harm” (Bell et al., 2021). Biodiversity can boost health through restorative experiences, and exposure to diverse environmental microbiomes is crucial for immune balance and the prevention of inflammatory disorders; it may also introduce allergens, pests, or risks of zoonotic diseases (Gandy, 2023). Health and safety requirements often encourage strictly controlled planting, yet ecological value depends partially on contact with living systems, such as soil organisms, insects and “dangerous wildlife” (Methorst et al., 2020). This poses the tension between reducing risk exposure and maintaining beneficial ecological connections. Plant selection further complicates this trade-off. The debate on “botanical sexism” indicates that the preference for planting male trees to minimize fruit and seed production may reduce maintenance demands but potentially increase pollen exposure and allergy risks (Hazbei et al., 2025; Katz et al., 2024). Species selection should therefore balance habitat value, reproductive diversity, safety, and maintenance requirements.

3.2 Spatial vitality vs. ecological traps

Incorporating natural elements into the built environment to create vibrant spaces sometimes inadvertently creates “ecological traps” that harm urban wildlife (Zuniga-Palacios et al., 2021). The use of large glass curtain walls to enhance visual contact with nature can lead to bird collisions and fatalities. At Chicago's McCormick Place, 21 years of monitoring identified illuminated windows as one of the major predictors of fatal bird collisions; reducing lighted window area to low levels was estimated to cut mortality by about 60% (Van Doren et al., 2021). Spaces designed to maximize human use through foot traffic, recreational activities, lighting, or commercial operations may further degrade habitat quality. Near heavily used forest trails, bird density and species richness were 13% and 4% lower than at sites farther from trails (Bötsch et al., 2018). This creates a sharp trade-off between spatial activation and ecological conservation, as the features that vitalize green spaces and foster human connectedness to nature can undermine livability for other species. Nature-inclusive projects should integrate safe habitats and quiet refuges for wildlife alongside spaces designed for human use.

3.3 Maintenance efficiency vs. ecological processes

The easier it is to maintain green spaces in buildings, the more likely they are to become decorative features rather than functional habitats, presenting a trade-off between operational convenience and ecological authenticity. Many projects integrating nature achieve visual success largely by being meticulously maintained (pruning and replacing plants more often) and simplifying the species composition to ensure manageability (Zhong et al., 2024). A review of 92 studies found a consistent negative association between mowing intensity and plant diversity, while responses among invertebrates varied across taxa and maintenance regimes (Liordos et al., 2020). True habitats are rarely as neatly trimmed as these. Ecological processes depend on change, succession, decomposition, and the formation of microhabitats, all of which may appear chaotic from the perspective of building management. Differentiated mowing, selective pruning, and retaining dead branches, fallen leaves or dead stems where safety permits can promote seasonal growth, spontaneous colonization, and habitat heterogeneity.

3.4 Perceived nature vs. ecological function

Humans perceive nature not only with love (biophilia) but also with fear and aversion, known as “biophobia” (Wilson, 1993). Nature-inclusive architecture sometimes prioritizes human preferences and excludes species that are “less appealing” but ecologically vital, such as spiders or snakes, which may trigger negative emotional responses. A survey of 600 residents in Greece found that likeability was the strongest predictor of whether people wanted more encounters with a wildlife taxon, with butterflies and songbirds among the most preferred species (Liordos et al., 2020). This human-centered filtering creates a gap between the perceived “nature” and the actual needs of a functioning ecosystem. Marginalizing species that lack visual appeal may exclude groups with different values, hindering the ecological functions necessary to support broader urban biodiversity. Designs incorporating ecological interpretation hold the potential to enhance the acceptance of “undesirable” species and other ecologically valuable elements.

3.5 Ecological livability vs. social equity

The benefits people derive from nature-inclusive architecture are often unevenly distributed. Wealthier neighborhoods typically feature more diverse vegetation and better-maintained green spaces, reflecting a “luxury effect” (Eyster et al., 2024; Hazbei et al., 2025). Improved greening may increase land and property values, but it can lead to green gentrification and the displacement of low-income residents, especially where green spaces are scarce and housing protections are weak (Ceballos and Jato-espino, 2026). The social performance of building-integrated greenery should therefore be assessed through affordability, shared access, and the distribution of benefits across neighborhoods.

4 Typologies of three-dimensional green spaces

Nature-inclusive architecture encompasses various types of green spaces that differ in their potential contributions to health and biodiversity. The preceding discussion indicates that synergies emerge when green spaces provide habitats, environmental comfort, perceptible nature experiences, and opportunities for physical activity and shared stewardship. These spaces may also introduce safety risks, ecological disturbance, high maintenance demands, and unequal access. Understanding the strengths and challenges of different types of green spaces can inform design decisions that enhance synergies and manage trade-offs. Taking three-dimensional green spaces as an example, they can be classified into nine types based on the openness and verticality of spaces (Table 1).

Table 1. Strengths and challenges of various spatial types of three-dimensional green spaces in buildings.

This typology translates the preceding synergies and trade-offs into a context-sensitive and performance-oriented framework. Context-sensitive design responds to spatial position, microclimate, access, and surrounding ecology; performance-oriented design considers factors such as health outcomes, habitat quality, environmental comfort, maintenance demand, risk exposure, and accessibility.

5 Conclusion

Nature-inclusive architecture, particularly through three-dimensional green spaces, offers a promising yet complex pathway for aligning dense urban development with ecological and health goals. Its contributions to human health and urban biodiversity depend on how synergies and trade-offs are addressed. It can support stress reduction, cognitive performance, positive emotions, physical activity and social cohesion, while creating challenges related to hygiene and safety, wildlife disturbance, maintenance, ecological function, accessibility, and social equity. Hence, the effectiveness of nature-inclusive architecture relies more on the configuration, perception, and experience of the biodiverse environment than on the mere presence of greenery. Different spatial types present distinct benefits and limitations, highlighting the need for tailored design rather than a one-size-fits-all approach. The proposed typology can guide the selection and combination of three-dimensional green spaces according to site conditions and intended health and biodiversity outcomes. When design decisions address trade-offs and accommodate both human and non-human needs, nature-inclusive architecture can function as socio-ecological infrastructure in dense urban environments.

Generative AI statement

The author(s) declared that Generative AI was not used in the creation of this manuscript.

Any alternative text (alt text) provided alongside figures in this article has been generated by Frontiers with the support of artificial intelligence and reasonable efforts have been made to ensure accuracy, including review by the authors wherever possible. If you identify any issues, please contact us.

Publisher's note

All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.

Footnotes

Edited by: Holger Muehlan, Health and Medical University Erfurt, Germany

Reviewed by: Horacio Samaniego, Universidad Austral de Chile, Chile

Morteza Hazbei, Concordia University, Canada