The authors ground their argument in a stark demographic reality. Urban residents spend nearly 90 percent of their time indoors, which makes buildings critical spaces for reconfiguring the human relationship with nature. In dense cities, nature-inclusive architecture typically materializes as three-dimensional green spaces—sky terraces, green balconies, and vertical gardens—representing a shift from horizontal greening to volumetric, vertically distributed ecological systems. These building-integrated green spaces can serve as ecological nodes distributed across a city’s vertical axis, supplementing limited ground-level greenery and providing habitats for urban flora and fauna. Yet Zhong and Li caution that optimistic narratives often mask uneven performance in practice. Human demands for comfort, safety, and ease of maintenance can conflict directly with the chaotic nature of functional ecosystems, and mutual benefit between human wellbeing and non-human habitat needs is by no means automatic.

The synergies, when they occur, are impressive and well documented. The authors cite a ten-year assessment of an intensive green roof with a bioreceptive façade at a French school that recorded 345 species, including 207 plants, 100 invertebrates, 20 birds, and a few reptiles and bats—biodiversity levels comparable to nearby parks. Such findings suggest that buildings can function as genuine ecosystems rather than decorative landscapes. The psychological co-benefits are equally striking. People who regularly watched and fed garden birds reported feeling more relaxed and connected to nature, and research cited in the article found that just two weeks of a nature intervention during winter enhanced positive affect, hope, and nature connectedness. Observing pollinators, seasonal plant changes, or bird activity in rooftop gardens and balconies can strengthen residents’ emotional attachment to the living world, making habitat provision and psychological connection mutually reinforcing rather than isolated.

Biodiversity and environmental comfort can also rise together when plant traits are matched to local conditions. A survey of vertical greenery systems in Singapore showed that vegetated walls support greater animal diversity than bare walls while cooling building surfaces during the day and providing insulation at night. On an extensive green roof in Rome, native Mediterranean perennials outperformed the common Sedum album in plant health, coverage, and flowering, and the temperature in the planted area was 2.9 to 4.4 degrees Celsius lower than in the adjacent concrete area. A comparative roof study identified vegetation cover, plant assemblage, season, and urban location as key determinants of thermal performance. Vegetation can even remove airborne pollutants, although dense planting may restrict airflow in poorly ventilated settings, and extensive green roofs reduced noise by 1 to 4 dBA, with performance shaped by plant cover, substrate, moisture, and gaps in the planting. The technical lesson is precise: biodiversity and comfort are jointly enhanced only when system configurations respond to local climate, water availability, substrate conditions, and target species.

Species richness itself appears to amplify the human experience of these spaces. Environments featuring diverse elements such as plants, birds, and butterflies are more effective at boosting perceived restorativeness and subjective vitality, and perceived bird biodiversity contributed to emotional wellbeing through restorativeness during nature walks. Office workers rated living roofs more favorably than bare concrete roofs, with tall, green, grassy, and flowering vegetation receiving the highest preference and restoration ratings. Multisensory biophilic environments—birdsong, rustling leaves, floral scents—have the potential to enhance satisfaction and cognitive performance while assisting stress reduction. Environmental preferences also drive physical activity: 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. 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. Social cohesion follows a similar pattern—a survey of 1,249 Singapore residents found that frequent garden visits and stronger experiential connections to nature predicted a sense of belonging and greater social cohesion, while community gardens in Berlin generated environmental learning and a sense of place.

But the trade-offs are where the article becomes genuinely provocative. The first tension lies between access to nature and hygiene and safety. Exposure to diverse environmental microbiomes is crucial for immune balance and the prevention of inflammatory disorders, yet building-integrated biodiversity may also introduce allergens, pests, or risks of zoonotic disease. Health and safety requirements often encourage strictly controlled planting, while ecological value depends partially on contact with living systems such as soil organisms, insects, and so-called dangerous wildlife. Plant selection compounds the dilemma: the debate over 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. Species selection must therefore balance habitat value, reproductive diversity, safety, and maintenance requirements—a balancing act with no universal solution.

The second trade-off is sharper still: spatial vitality versus ecological traps. Large glass curtain walls designed 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, and reducing lighted window area to low levels was estimated to cut mortality by about 60 percent. Spaces designed to maximize human use through foot traffic, recreation, lighting, or commercial operations may further degrade habitat quality—near heavily used forest trails, bird density and species richness were 13 percent and 4 percent lower than at sites farther from trails. Maintenance efficiency presents a third contradiction: the easier green spaces are to maintain, the more likely they become decorative features rather than functional habitats. A review of 92 studies found a consistent negative association between mowing intensity and plant diversity, while invertebrate responses varied across taxa and maintenance regimes. True habitats are rarely as neatly trimmed as meticulously managed projects; ecological processes depend on change, succession, decomposition, and microhabitat formation, all of which may appear chaotic from a building-management perspective. Differentiated mowing, selective pruning, and retaining dead branches or fallen leaves where safety permits can promote seasonal growth, spontaneous colonization, and habitat heterogeneity.

Human perception introduces yet another filter. Humans perceive nature not only with love—biophilia—but also with fear and aversion, known as biophobia. Nature-inclusive architecture sometimes prioritizes human preferences and excludes species that are less appealing but ecologically vital, such as spiders or snakes. 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. This human-centered filtering creates a gap between perceived nature and the actual needs of a functioning ecosystem, and marginalizing species that lack visual appeal may exclude groups with different values while hindering ecological functions. Equity concerns complete the picture: wealthier neighborhoods typically feature more diverse vegetation and better-maintained green spaces, reflecting a luxury effect, and improved greening can raise land and property values, triggering green gentrification and the displacement of low-income residents, especially where green spaces are scarce and housing protections are weak.

To translate these tensions into actionable design, Zhong and Li propose a typology that classifies three-dimensional green spaces into nine types based on spatial verticality—sky, elevated, and ground—and openness—open, semi-open, and closed. Open rooftop gardens offer high habitat potential and outdoor nature access on high floors but demand structural load capacity, wind resistance, safety systems, and climate-tolerant plants. Green balconies function as stepping stones in vertical greenery systems, bringing nature to every floor at high initial investment and operational cost. Closed indoor gardens, whether at top-floor or atrium level, provide year-round greenery in controlled environments and restorative experiential benefits indoors, but carry risks of allergies and pest issues, potential ecological traps, high energy and maintenance demands, and limited ecological connectivity. Ground-level open and semi-open gardens support soil-based ecosystems and species richness accessible to more users, but compete directly with land use in dense cities. The framework is explicitly context-sensitive and performance-oriented, responding to spatial position, microclimate, access, and surrounding ecology while weighing health outcomes, habitat quality, maintenance demand, risk exposure, and accessibility.

The article’s ultimate message is that 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. When design decisions address trade-offs and accommodate both human and non-human needs, building-integrated nature can function as socio-ecological infrastructure in dense urban environments—supporting stress reduction, cognitive performance, positive emotions, physical activity, and social cohesion while creating genuine habitats. But when projects chase visual success through meticulous maintenance and simplified species composition, or when benefits flow unevenly across neighborhoods, the same architecture can become green wallpaper: pleasant to look at, ecologically hollow, and socially exclusive. For a discipline racing to greenify the vertical city, the authors offer a demanding but clarifying standard—tailored design rather than a one-size-fits-all approach, guided by site conditions and intended health and biodiversity outcomes, and honest about the chaotic, sometimes inconvenient reality of sharing our buildings with other species.

Subject of Research: Urban Ecology and Architecture

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

Article References: Zhong, W., & Li, X. (2026). Synergies and trade-offs of nature-inclusive architecture in dense cities: between human health and urban biodiversity. Frontiers in Sustainable Cities, 8, Article 1843807. https://doi.org/10.3389/frsc.2026.1843807

Image Credits: AI Generated

DOI: 10.3389/frsc.2026.1843807

Keywords: nature-inclusive architecture, urban biodiversity, biophilic design, green roofs, vertical greenery, dense cities, green gentrification, ecological traps, human health, multispecies urbanism, Synergies, trade-offs