Green densification model

The Parco della Musica in Cagliari, inaugurated in 2011 by the municipality of Cagliari, blends modern urban design with a focus on green spaces, music, and culture. Spanning approximately five hectares, the park features a small, winding artificial river that flows from north to south, creating a micro-habitat for various bird species. This waterway, lined with benches on the western side and open green spaces on the eastern side, offers a peaceful setting for both wildlife and visitors. The use of native plants, trees, and shrubs further enhances the biodiversity.

In terms of construction, the use of sustainable materials like marble paving and wooden platforms reflects a commitment to modern design. This makes the Parco della Musica an ideal venue for hosting events and fostering social interaction where culture can thrive, and people can relax and enjoy fresh, calm spaces. Overall, the Parco della Musica serves as an example of how modern urban spaces can be designed to promote ecological balance while offering cultural and recreational benefits to the community (Refs. 1, 2, 3, 4 & 5).

The "Parco degli Anelli" is a new green space project in Cagliari, located along the waterfront in the Sant'Elia district. Designed by Portuguese landscape architect João Ferreira Nunes and inaugurated in 2019, the park spans approximately 15 hectares, with over 4 hectares currently accessible to the public. The remaining area will undergo renovation in the next two phases of the project. The park is notable for its open design, free of walls and fences, and its direct access to the sea, making it a unique addition to the city's green spaces (Refs. 1, 2 & 7).
This park exemplifies urban renewal by transforming a previously neglected and degraded area into a green, accessible to all public space. It is part of a broader context of redevelopment of peripheral neighborhoods, in this case the Sant'Elia district.(Refs. 6 & 9).
Parco degli Anelli features flat terrain with numerous pedestrian and cycling paths for individual sports activities, along with expansive grassy areas covering about 27,000 square meters. The park is surrounded by approximately 500 newly planted trees and shrubs typical of Mediterranean maquis, including Aleppo pine, dwarf palm, European olive, and jacaranda.
Future plans for the park include expanding into additional areas and connecting it to the rest of the city via a pedestrian and cycling bridge over the Palma Canal, as well as connecting it to the new waterfront promenade that is being built from Via Roma to Marina Piccola (Refs. 1, 2 & 7).

The reforestation project at Bela Vista Park in Lisbon is a collaborative effort by the MEO Kalorama music festival, the Lisbon City Council, and Quercus (local NGO). The intervention began with a community planting event in February 2024 with the planting of 80 native trees, and the goal to plant a total of a total of 1,000 trees. The project aimed to improve the park's biodiversity, enhance carbon absorption, and support local wildlife. The tree species were chosen for their suitability to the local climate and their ability to integrate with existing vegetation. Local schoolchildren and residents participated in the planting, serving as a community engagement activity. This initiative is part of broader efforts to make Lisbon greener and to positively contribute to the local environment, given the disturbance caused by the MEO Kalorama festival (Ref 1, 2, 3).

The Horpaz-Ezareni Park is an initiative driven by civil society, requesting the municipality of Miroslava to construct a natural park adjacent to Lake Ezareni. The aim is to protect its green spaces and aquatic bird species while addressing waste management in the area. The petition also called for more green spaces in line with European standards and sought to tackle the challenges of rapid urbanization in peri-urban areas. It collected hundreds of signatures and targeted an area of 20 hectares.
In response, the municipality agreed to the petition and initially proposed creating a park covering 4 hectares in 2022. This first plan was released to the public for consultation. However, the project has since evolved to encompass the original 20 hectares, plus an additional 2 hectares, with an estimated project cost of 11,000,000 euros and a timeline of 3 years for implementation.
The park's design includes various facilities and amenities aimed at enhancing opportunities for recreation, exercise, and relaxation. Accessible paths for pedestrians and cyclists, as well as a parking lot, are also part of the plan. Additionally, two buildings are proposed for sanitary and administrative purposes, which would manage the projected installations of a lighting system, Wi-Fi, and surveillance cameras.
Environmentally, the project includes plans for managing the lake's banks to remove hydrophilic vegetation that could create an unhealthy environment, along with the construction of two bridges. The wilderness areas will be managed, and dendrological plants will be introduced to improve the ecosystem's quality. Overall, the project aims to increase and regenerate green spaces in the commune, enhancing the quality of life for residents and improving the area's aesthetic appeal. (1-8)

Since the 1980s, the Graefekiez neighborhood in Berlin's Friedrichshain-Kreuzberg district has been a traffic-calmed area where all road users are treated equally, driving is limited to walking speed, and cars are permitted to stop anywhere. However, this once-progressive concept no longer functions effectively due to the significant increase in cars and delivery vehicles over the years. The streets no longer resemble a traffic-calmed zone, with traditional layouts featuring roadways, sidewalks, and parking spaces. As a result, many users fail to recognize the traffic-calmed nature of the area, leading to safety issues: vehicles drive too fast, delivery traffic causes conflicts, and streets are difficult to navigate safely.
Berlin’s transport sector faces the challenge of meeting legally mandated CO₂ reduction targets. Achieving these goals requires bold measures, including limiting private motorized transport (MIV), especially in densely populated areas where residents and visitors have access to alternative modes of transportation.
The "Graefekiez" project addresses these challenges through urban redevelopment aimed at improving livability and promoting sustainable urban mobility. Car parking has been banned from the streets, freeing up space for communal use such as lounge areas. As part of the "Graefekiez" project, the district office is converting parking spaces into green spaces and expanding tree disks to adapt to the climate and promote a sponge city.
The project was developed collaboratively with residents and NGOs through a participatory process led by the Friedrichshain-Kreuzberg district office, in partnership with the Berlin Social Science Center and Paper Planes e.V. Implementation began in 2023 on Graefestraße and Bockhstraße.After a six-month trial period, the district office decided in 2024 to make the measures permanent.
This initiative advances a safer, greener, inclusive urban environment while meeting climate and community goals. (Ref. 1, 2, 3)

The park called Järnvågsparken will be constructed in the developing neighbourhood of Masthuggskajen as the main green space of the area, measuring about 8000 m2. The park will offer recreational activities for people living and working in the area, with spaces designated for rest, meetings, picnics, walking and play. For example, there will be a large playground, many different places to sit, grass lawns and a space to host cultural events in [Ref. 1-4]. The park will also be designed to manage stormwater and reduce flood risk [Ref. 5, 6]. The park will be built over an existing highway, turning it into a tunnel while reconnecting the new neighbourhood. The remaining future park area next to the road are currently parking spaces [Ref. 1, 4, 5]. The adjacent streets will also see more greening, increasing the connectivity of green spaces and mobility [Ref. 4-6]. The location on top of a tunnel limits the soil depth of the park, but the ambition is still to house a rich plant and animal life, including trees, providing ecosystem services [Ref. 1-6]. The project is managed by the City of Gothenburg [Ref. 1, 7].

The "Un Millón de Corales por Colombia" project is a national initiative aimed at the restoration and conservation of coral reefs across Colombia. Initiated in 2021, this ambitious project seeks to rehabilitate 200 hectares of coral reef by planting one million coral fragments across seven departments in Colombia, spanning both the Caribbean and Pacific regions​ (ref 1,2). It was developed as a response to the significant degradation of coral reefs caused by climate change, coastal development, overfishing, and pollution. These factors have led to the loss of about 80% of coral reefs in the Caribbean region.
The initiative, led by the Colombian government in partnership with organizations such as Conservación Internacional, Parques Nacionales Naturales, Corales de Paz, and several regional environmental authorities, focuses on restoring this vital ecosystem (ref 2). The project encompasses constructing and maintaining coral nurseries and training local community members, including fishermen, as "coral gardeners." These gardeners are taught scientifically proven coral restoration techniques, including microfragmentation and larval rearing methods. A key aspect of the project involves continuous education and involvement of the community and stakeholders to ensure long-term sustainability (ref 4, 5). In Cartagena, the project plays a vital role in the restoration and conservation of coral reefs in this region, which is a key site for the initiative (ref 4).

The project, implemented by the municipality of Cagliari, involves the creation of a new garden in 2021 on Via Eroi d’Italia, in the Pirri municipality, located about 5 km from the center of Cagliari. This initiative is part of a broader effort to reclaim degraded urban green spaces. The garden spans approximately 900 square meters and was previously an unused lot serving as a parking area. Its transformation required substantial groundwork, including soil scarification and leveling, to prepare the area for its new purpose. The garden is now enclosed, with pedestrian access via two gates leading to a paved walkway.
Inside, the garden is divided into two main sections: a children's play area and a landscaped green space. The play area covers about 100 square meters and features durable artificial grass, swings, a spring toy, a universally accessible table, a children's table, benches, and a multi-compartment recycling bin. The green space, approximately 200 square meters, is planted with low-water-use grass and surrounded by drought-resistant plants like albizia, oleander, and lantana, chosen for their low water consumption and resilience to environmental stress. An underground irrigation system, linked to a 5,000-liter water tank, ensures efficient water use.
The remaining 600 sqm outside forms a parking area with 1 disabled space, 2 motorcycle spaces, 1 bicycle rack, and 15 car spaces.
The garden also incorporates sustainable elements, such as LED lighting for energy efficiency and a mural by renowned Sardinian artist Manu Invisible, depicting sunlit forest undergrowth in shades of green. This project responds to citizens' requests and prioritizes resource efficiency by reducing hazardous substances and minimizing waste. The materials used, including recycled plastics, and the selection of plants were chosen to match local ecological conditions, enhancing the garden's sustainability and reducing its environmental impact (Refs. 1, 2, 3, 4 & 5).

A small biodiversity park was established in Härlanda Park, an old prison complex which today houses a culture centre, a pre-school and office space. The area was previously used as a small lily garden, but this project implements more biodiversity-promoting features such as a bee hive, varied flowers and trees, different types of soil and insect hotels. The municipal real estate company Higab owns the park and partnered with Stadskupan, which works with urban beekeeping, biodiversity, and rewilding, to design and create the park. They also involved Vägen ut! (translates to "the way out"), a social enterprise that employs people who are far from the labour market due to substance abuse issues to help maintain the park in a socially inclusive way. The park has pedagogic features and events for local businesses and organisations as well as the public. The beehive was established in 2022, while the entire biodiversity park was established in 2023. The project will go on for three years and be evaluated yearly. [Ref. 1, 2, 3].

The Phoenix Park initiative was carried out by the "Gheorghe Asachi" Technical University of Iași in partnership with the Iași Communitarian Foundation, the BorgWagner Fund, and the Municipality of Iași. It involved the rehabilitation of a green space within the university campus. Covering an area of 3,000 square meters, the renovation was based on the winning design from a student competition focused on improving campus spaces.
The park was designed to include facilities for physical exercise (calisthenics equipment), recreation (badminton court and ping-pong table), and social interaction spaces. It also serves as a buffer to reduce noise from the surrounding areas.
The total cost of the project amounted to 121,200 euros, with the university covering infrastructure expenses, the municipality providing the labor for rehabilitation, and the private fund contributing 15,150 euros. The implementation of the design was overseen by the student designer and coordinated by the NGO and the university’s Association of Student Architects.
This initiative is part of a larger urban regeneration project by the university, in collaboration with the municipality and the Communitarian Foundation, where several campus green spaces are being rehabilitated based on student designs. The overarching goal is to enhance students' quality of life and promote healthy lifestyles through the creation of green spaces during their time at the university. (1, 2, 5, 6, 8, 13, p. 92)