Green densification model

The "Há Vida no Meu Bairro" project is an innovative urban initiative led by the Lisbon City Council aimed at transforming the city into a "15-minute city." This concept ensures that all essential urban functions, such as commerce, green spaces, education, sports, culture, health, and social support, are within a 15-minute walk from residents' homes. The project promotes neighbourhood identity, quality of life, active mobility, and the development of safer, more comfortable public spaces. By integrating these elements, the initiative seeks to create multifunctional neighbourhoods where daily needs can be met locally, reducing dependence on cars and enhancing pedestrian accessibility (Ref 1).
Lisbon's approach is both city-wide and neighbourhood-specific, with pilot projects being developed in collaboration with the city's 24 parishes. These projects focus on improving public spaces and pedestrian mobility, reinforcing the city's commitment to sustainability and community engagement (Ref 2). The initiative also emphasizes the importance of public participation, encouraging residents to contribute to the design and development of their neighbourhoods and enhancement of local identity and green spaces (Ref 3).

Cagliari's waterfront is currently characterized by extensive soil sealing, which has rendered the soil impermeable, leading to a loss of biodiversity and contributing to the urban heat island effect. Additionally, the waterfront is disconnected from the city due to heavy traffic. In 2023, the Municipality of Cagliari launched the "Green Promenade for Cagliari’s Seafront" project, aimed at revitalizing the waterfront and reconnecting the city with its coastal heritage. Led by Stefano Boeri Architetti, the project seeks to transform the area into a continuous green space that integrates pedestrian pathways with shaded public areas, functioning as a "green lung" to mitigate urban heat and enhance biodiversity.
The initiative will introduce over 200 new trees and 5,700 square meters of green space, creating a park that beautifies the area, improves air quality, and lowers local temperatures. A key focus of the project is fostering cultural and social inclusion by developing new community hubs that encourage diverse activities and strengthen social cohesion. Additional features include recreational areas, sports fields, and outdoor seating. (Ref. 1, 2,3)
The project also aims to enhance social inclusion, environmental sustainability, and urban connectivity, ultimately transforming the waterfront into a vibrant public space that reflects Cagliari’s identity.
However, the lengthy construction process has disrupted local businesses and reduced foot traffic, making the area less attractive during the redevelopment phase. (Refs. 10, 11, 12 & 13).

Named after the former Mexican president Lázaro Cárdenas, this green corridor project stretches over 4,5 km throughout one of the most densely populated areas in Belgrade. It was first built in the 1970s, connecting the building blocks 45, 44 and 70 of Novi Beograd, but has deteriorated since then (Ref. 4,9). Given the fact that close to 40.000 people live in the area which its highly vulnerable to climate change, action was taken to fully reconstruct the corridor for the benefit of local and surrounding residents (Ref. 3,4).
The project was implemented in three phases, according to the three blocks adjacent to the construction site starting in 2019. During the third implementation phase in 2022, however, major delays occurred due to disagreements with the local neighbourhood association "Common Action Block 70 and 70a", which demanded to be taken into consideration in the project's design (Ref. 2,5). Despite some cooperation between the responsible authority (Greenery Belgrade) and the association, demands could not be met (Ref. 5). In the end, the project was carried out as originally planned by the authorities, with a delay of approximately one year. Ultimately, the green corridor provides ample amenities for sports (bicycle lanes, basketball courts, playgrounds, etc.) and recreational activities (benches, chess area) as well as low-barrier infrastructure for all age groups (Ref. 9).
The project was initiated by President Aleksandar Vučić and supported by the current mayor of Belgrade, Šapić, who both have roots in the district (Ref. 4,6).

The "Parque Espíritu del Manglar" in Cartagena is a multi-zone public space designed to promote recreation, environmental awareness, and cultural identity. The park, which has undergone a significant reconstruction, offers a wide array of recreational equipment and spaces for contemplation in a natural setting. It is divided into six thematic zones: Entrance Zone; Sports Area, Open-Air Theatre, the Tertulia Island, offering scenic views, public restrooms, and statues such as the iconic "Macondo" tree, a tribute donated by Gabriel García Márquez’s family; Children’s Central Zone, featuring a pirate-themed mangrove ship and an Environmental Observation Deck. (ref 1).
With the reopening of the park, EPA Cartagena introduced an ecological trail on Tertulia Island, where a mangrove restoration process has been carried out, focusing on plant health and climate resilience. This area also hosts wildlife such as macaws, sloths, turtles, raccoons, and green herons—species that cannot be reintroduced into their natural habitats. (ref 2)
The park now serves as an active site for environmental education, particularly for children, with programs addressing solid waste separation, climate change, and the protection of natural resources. Its reopening has also been recognized as a key step in strengthening family-oriented tourism and promoting sustainable urban development in Cartagena. (ref 2)

The project aims to modernize Ciurchi Park, also known as "Tătărași Park," due to the degraded state of its current infrastructure (1 - 8). Initiated by the Municipality of Iași, the initiative seeks furthermore to increase the amount of green space per inhabitant in the city and reduce overcrowding in other parks, thereby diversifying options for citizens (1 - 9). Planning for the project began in 2022, and the bidding process for its execution was released in April 2024, which is still awaiting a decision (1, 2. 7).
The implementation is expected to involve interventions in existing green spaces, including the planting of 120 trees, 1,000 bushes, and approximately 2,000 species of flowers and ornamental plants. The project will also feature a monitoring program for tree species, management of existing vegetation to protect healthy trees, and removal of invasive or degraded plants (1, 2, 4, 8). Additionally, it will include benches, facilities for physical exercise, an underground waste collector, and a rainwater drainage system, among other infrastructure improvements (1 to 8).
The project is expected to be financed by the local budget and EU funds, with a total estimated cost exceeding 5,000,000 euros, including taxes (2, 4). It is included in the Integrated Urban Development Strategy 2015-2030 for the city (8, p. 12).
The goals of the project are to modernize the park, improve accessibility for citizens in the surrounding area, minimize management costs for the municipality, ensure a sustainable habitat for flora and fauna with minimal invasive interventions, and harmonize architectural proposals with the landscape (6, 8, p. 32). Other objectives include protecting biodiversity, enhancing the park’s aesthetics and the overall city environment, and reducing CO2 emissions, which will ultimately improve the quality of life for surrounding residents (8, p. 141).

The renovation of the "Marechal Humberto Delgado" Square focused on transforming the area into a more pedestrian-friendly and sustainable urban space. The project included reorganising the traffic system, creating a new urban green square, requalifying the bus terminal, enhancing the integration of different transport modes and improving pedestrian access (Ref 1). Key features of the intervention were the introduction of cycle paths, wider sidewalks, green spaces with 200 new trees, and recreational facilities such as a children's playground and water features (Ref 2). The project also addressed critical infrastructural needs, including constructing a rainwater collector as part of Lisbon's General Drainage Plan to mitigate the city's frequent flooding issues (Ref 3). The renovation, completed in 2024, was part of the 'A Square in Every Neighborhood' program, emphasizing community involvement and sustainable urban development (Ref 3).

The Detroit RiverWalk is an urban development project along the Detroit River, designed to reconnect residents with their waterfront and revitalize a historically industrial area. Once characterized by abandoned buildings and industrial debris, the riverfront between the MacArthur and Ambassador Bridges had long been inaccessible to the public. To address this, the Detroit Riverfront Conservancy was established in 2003 to lead the redevelopment of this space.
The RiverWalk currently stretches along a 3.5-mile section, with plans to expand to 5.5 miles, integrating ecological restoration, public access, and recreational opportunities. The esplanade features native landscaping, artistic elements, and amenities, including four pavilions, a custom carousel, and areas for fishing, walking, biking, and inline skating.
Environmental remediation has been a crucial part of the project. In collaboration with the U.S. Environmental Protection Agency’s Great Lakes National Program Office, the Detroit Riverfront Conservancy successfully cleaned up 13,000 cubic yards of contaminated sediment, significantly reducing pollution and contributing to the removal of the Detroit River from the list of the most polluted sites in the Great Lakes. Furthermore, the project also includes greenways, park creation and revitalization.
The RiverWalk is not just a public space; it symbolizes Detroit’s transformation from a Rust Belt city to a sustainable urban environment. It exemplifies the power of public-private partnerships in revitalizing urban areas. The RiverWalk continues to expand, with plans to connect various parks and extend to the Ambassador Bridge, further enhancing the city’s waterfront. Its success was recognized in 2021 when it was named the Best Riverwalk in America by USA Today, cementing its status as a model for urban renewal and community engagement. (Ref. 1, 2, 3, 4)

In 2021, the real estate company Inamstro, in collaboration with the Municipality of Iași, the civil organization "Glasul Vieții" (Voice of Life), and local citizens, initiated a tree-planting initiative that involved planting 250 trees near a residential area and a parking lot in the Frumoasa neighborhood of Iași. This neighborhood is smaller compared to other areas of the city and was developed during the communist systematization of the 1970s and 1980s. It consists of groups of four-story blocks arranged around common spaces, situated near the Frumoasa Monastery complex.
The main goals of the 2021 planting action were to enhance green space, lower air temperatures, reduce urban air pollutants—such as fine particulate matter—absorb CO2, and improve overall health and quality of life (1–5). Additionally, the implementing company concluded that the trees planted near residential areas can significantly reduce energy needs for air conditioning and heating, leading to an average cost decrease of 30% during summer and winter (1, 2).
Volunteers participating in the project received a "tree certificate," signifying their commitment to planting and adopting a tree (7). In this initiative, volunteers were also tasked with monitoring the growth of their adopted trees to ensure their health (1–6).

Barranco, the smallest district of Metropolitan Lima, is suffering from serious environmental problems that are affecting its inhabitants. Environmental degradation is a consequence of the increase in large buildings (real estate boom), which reduces green space areas and causes a deficit of vegetation in the district. Additionally, there are high levels of air pollution due to car traffic, which has been accentuated by the lack of green areas in the area, which affects the environmental quality and the population's quality of life (1).
Additionally, the district doesn't have more free public areas where new green areas can be created. Due to these combined pressures, the local government has looked for alternatives, considering private areas, which have a high potential to implement green roofs and vertical gardens, which can contribute to face Climate Change as a mitigation strategy and improve the quality of life (1). The Green Roofs and Green Walls strategy is proposed to build citizen culture, nature appreciation, landscape, and ecosystems (2, 3). The aim is, therefore, to encourage the inhabitants of the district to progressively install green roofs and walls, employing an economic incentive in the taxes paid to maintain public green areas (4).
The programme is oriented to generate environmental benefits such as the reduction of air pollution, acoustic insulation, thermal comfort, and increase of green areas (m2) per inhabitant, and social benefits such as the improvement of the living conditions and health of the inhabitants of the district (1, 3), the promotion of social relations (1), the aesthetic improvement of the city, and the possibility of producing food for self-consumption, as there is support in the implementation of hydroponic systems in the green walls and roofs (1, 3). Its implementation focuses on new, under construction or existing residential, commercial, office or lodging buildings (3).

The municipal real estate company Higab partnered with The Foodprint Lab Architects, an architecture firm specialising in food system design, in a three-year pilot project to create urban farms in three of their properties in Gothenburg. The Foodprint Lab designed the urban farms based on the conditions of each property and connected Higab with potential farmers. The urban farms are located at Slakthuset (an old industrial area), Kviberg (by an empty building undergoing renovation) and Musikens hus (an old building used for music events and a restaurant). The farms are established in unused, mostly grey areas such as parking lots. In all sites, the farming is run by local farming associations; some sell vegetables on site and in Kviberg, there has also been a commercial production of vegetables. Sustainable food production, entrepreneurship opportunities, a nicer and safer environment, and the promotion of biodiversity are highlighted as benefits of the project. In total, about 50 different plant species are found across the locations. The establishment of the urban farms was part of the Grow Gothenburg project within the Sharing Cities Sweden program, which provided some of the funding [Ref. 1-5, 7].