3.4. Definition of project actions
According to a participatory planning approach, the district's residents have been involved in 3 meetings to define the possible project actions. These meetings have been organized following the “world cafè” methodology to create a safe, welcoming environment in which to intentionally connect multiple ideas and perspectives by engaging participants in several rounds of small-group conversation. At the start of the first World Cafè the results of the SWOT Analysis were shown and explained to give the participants the same knowledge base. In each World Café meeting, participants (60 people) were divided into 3 tables and had an hour and a half to discuss possible projects to implement in the area. In each meeting there were three rounds (i.e. three table’s changes for each participant). Each table had a “host” who remained at the table through the entire exercise. The host’s role was to welcome participants to the table, provide an overview of the discussion question, and summarize key ideas shared by previous guests at the table. At the end of the exercise, the host was responsible for sharing a summary of the discussion points from his or her table. The following projects emerged from the World Café meetings:
Spirulina seaweed is a blue-green microalga (it belongs to the blue seaweed group). It is a highly regarded superfood due to its status as a complete nutritional source. This type of algae thrives in freshwater environments such as lakes, rivers, and ponds. Spirulina is rich in various nutrients, including fat-soluble vitamins (A, E, and K), essential fatty acids (DHA and EPA), beta carotene, and an array of minerals. While it serves as a protein source, it does not contain sufficient levels of some essential amino acids required for optimal bodily function, unless one has a medical condition that necessitates avoiding specific amino acids. Additionally, since spirulina originates from bacteria, specifically “cyanobacteria,” it is considered a viable protein option for vegans. The production plant uses photo bioreactors, or plastic tubular solar collectors in which pure groundwater circulates and in which the seaweed grows. This particular plant allows the least contact of water with air, preventing contamination of the algae.
- 2.
Hydroponics Systems
Hydroponics is a cultivation method where plants grow without soil. Nutrient-rich water, maintained at the ideal pH, supplies essential elements directly to the plant roots, ensuring efficient absorption. Unused water is recycled for reuse. Plants in hydroponic systems are supported by inert substrates like pumice or coconut fiber, or they are placed in tubular structures with flowing nutrient-rich water. Hydroponics bridges traditional agriculture and aquaculture. These systems feature water-filled basins housing fish. Plants, supported by slabs with holes, absorb nutrients directly from the water. Fish maintain water quality and provide nutrients for the plants. Hydroponic systems utilize inert substrates or tubular structures with flowing nutrient-rich water, eliminating the need for soil.
- 3.
Eco-compactor
Eco-compactors are recycling stations strategically placed in public areas. These machines accept various plastic caps, including PET, PS, PE, and HDPE bottles, as well as aluminum cans and PP glasses. Users receive a small monetary reward in the form of discount coupons for their contributions.
Eco-compactors are automated machines that sort and compact waste. Each deposit earns a receipt with a contribution or discount voucher redeemable at participating businesses. This incentive recycling model promotes environmental education.
- 4.
Little Composting System
Composting, also known as controlled decomposition, necessitates a careful balance between “green” organic materials and “brown” organic materials. “Green” materials, such as grass clippings, food scraps, and manure, are rich in nitrogen. In contrast, “brown” materials, including dry leaves, wood chips, and branches, are high in carbon but low in nitrogen. Achieving the ideal nutrient mix often requires experimentation and patience, which is an essential aspect of both the art and science of composting. The size of the particles used in composting plays a crucial role; grinding, chipping, and shredding materials increases the surface area available for microorganisms to feed on. Smaller particles not only create a more uniform compost mixture but also enhance pile insulation, helping to maintain optimal temperatures during the decomposition process.
- 5.
Co-Working
Coworking has gained significant traction in the digital knowledge economy, driven by the growing number of independent professionals who often work from home and may lack the social connections needed for feedback, referrals, and support. Shared experiences of working remotely and a mutual understanding of the challenges associated with personalized professional endeavors foster cognitive proximity within home-based coworking environments. Coworkers actively contribute to a productive atmosphere, which is supported by digital platforms, host engagement, and home-based features.
- 6.
Floor drainage
The impermeable surfaces of public parking lots generate a substantial amount of surface water runoff, necessitating effective channel drainage solutions. For larger commercial parking facilities, drainage systems are optimal for managing surface water, with larger designs offering additional capabilities. Multi-storey car parks and parking decks often face challenges related to limited installation space for drainage solutions. In St. Elia’s Masterplan, which includes numerous parking areas, has opted to prioritize sustainable environmental practices through the implementation of drainage systems.
- 7.
Buffer strip
A buffer strip is a designated area of land that is permanently covered with vegetation, designed to improve air, soil, and water quality while addressing various environmental issues, particularly in agricultural settings. These buffer strips effectively trap sediment and enhance the filtration of nutrients and pesticides by slowing surface runoff before it reaches local water bodies. The root systems of the vegetation in these strips help bind soil particles, reducing wind erosion and stabilizing stream banks, thus offering protection against severe erosion and landslides. Farmers can also utilize buffer strips to better align existing crop fields, which not only enhances safety for equipment but also promotes more efficient farming practices. Buffer strips can feature a variety of vegetation configurations, ranging from simple grass to combinations of grass, trees, and shrubs. Areas with diverse vegetation provide improved protection against nutrient and pesticide runoff while simultaneously fostering greater biodiversity among plants and animals.
- 8.
Urban Agriculture
Urban agriculture is transforming city landscapes, with a surge of small-scale operations dedicated to cultivating plants and raising animals at ground level or on rooftops and terraces. Urban horticulture encompasses the cultivation of vegetables, fruits, aromatic plants, and medicinal herbs, conducted either outdoors or in enclosed spaces on a domestic scale. Urban vegetable gardens minimize the number of intermediaries involved in the food supply chain, leading to reduced transportation, packaging, and storage costs. This not only increases the earnings of horticulturists but also decreases environmental pollution. Additionally, these initiatives create job opportunities for disadvantaged groups and individuals at risk of exclusion. Urban agriculture plays a vital role in providing fresh food to the population, creating green spaces, recycling municipal waste, and enhancing urban resilience against climate change. Urban vegetable gardens exemplify the principles of a sustainable city. Community gardens have evolved beyond mere vegetable plots to become spaces for leisure, relaxation, environmental education, and therapeutic experiences in natural settings. Many citizens now actively engage in private or community urban vegetable gardens, and municipal authorities increasingly incorporate these initiatives into their sustainable urban planning efforts.
- 9.
Kayak anchoring
A kayak anchoring action plan in the city focuses on creating accessible, sustainable, and eco-friendly facilities that integrate with urban spaces. Strategic locations near parks and public transport hubs encourage easy access, while sustainable materials and designs protect local ecosystems. These facilities link to green spaces, promoting outdoor recreation and healthy lifestyles. Community involvement is encouraged through educational programs on kayaking and water safety, and citizens can participate in environmental monitoring. The plan also supports local businesses by attracting visitors through rentals and tours, boosting the local economy. Additionally, cultural and historical connections can be highlighted along kayaking routes, enhancing the city's appeal. Smart technology and water management systems ensure the facilities are efficient, sustainable, and safe, turning kayak anchoring into a valuable urban asset.
- 10.
Cardio outdoor gym that generates electricity
The outdoor cardio equipment that generates electricity promotes not only physical health and mental well-being but also community spirit and environmental sustainability. This innovative equipment harnesses human energy and converts it into usable electricity, which can be utilized to charge mobile phones and tablets via a USB port and to illuminate on-site interactive lighting. While it is well established that physical activity enhances both physiological and psychological well-being, more evidence is needed to determine how various environments influence health outcomes. Additionally, exercising in outdoor settings appears to provide unique physiological and mental health benefits. However, people’s connection to nature seems to be evolving, which has significant implications for how humans engage with the natural world.
- 11.
District’s open-air market
The development of an open-air market within a district plays a crucial role in promoting local commerce, community engagement, and sustainability. It serves as a vibrant hub where local vendors sell fresh produce and handmade goods, fostering economic activity and cultural exchange. By supporting short food supply chains, the market reduces transportation and packaging, making it eco-friendly. It connects local farmers with residents, promoting trust in food quality and preserving local traditions, while also attracting tourists. Flexible in design, the market can host community events, creating a sense of unity and serving as a social and cultural focal point, aligned with the city’s environmental goals. The market would provide a platform for local farmers and producers to directly connect with residents, enhancing trust in the quality and origin of food. This setup would also help preserve and promote local food traditions, making it a point of interest for tourists seeking authentic experiences. The market could include designated areas for food vendors, craft stalls, and seasonal pop-up spaces for special events, contributing to the district’s identity as a center of sustainable, local living. Finally, the open-air market would integrate commerce, culture, and sustainability, enriching both the community and the city’s economic vitality.
- 12.
Solar panels
The stadium will feature solar panels installed on the root and most of its external vertical surfaces to harness solar energy during the day. A battery storage system will facilitate the accumulation of this collected energy, transforming the stadium into an “energy supply hub.” This setup will also help mitigate the grid impact of numerous electric vehicles charging simultaneously from various locations. As a key outcome, the stadium will achieve 100% energy self-sufficiency, with any surplus energy allocated for several purposes:
Illuminating poorly lit areas of the St. Bartolomeo district at night, thereby enhancing the livability of public spaces and promoting social activities;
Charging e-bikes and scooters for residents and visitors to Cagliari who are drawn to the stadium and the surrounding sports facilities.
- 13.
Energy-generating floor
The project foresees an energy-generating floor around the football pitch to harness energy from citizens walking in the area. These floors convert the kinetic energy generated by pedestrians into usable electricity, which can then be redirected to power nearby facilities, such as lighting for the pitch, surrounding pathways, or public amenities. The system promotes sustainability by encouraging green energy practices within the community while simultaneously enhancing the functionality of the space. By incorporating these energy-harvesting technologies, the city encourages active participation from its residents, linking physical activity to environmental benefits. The initiative also aligns with broader goals of smart city development, where technology and infrastructure work together to create more sustainable, energy-efficient urban environments.
- 14.
Cycling and walking paths
Enhance the availability of cycling and walking paths surrounding the Sant’Elia football stadium, which will have direct positive effects on:
- 15.
Tactical urban planning solutions for road intersections
In district mobilities, project strategies are aimed at the identification of strategic crossing and connection areas according to the main axes of connection identified. Tactical urban planning uses low-cost, temporary solutions to improve road intersections while working toward permanent changes. Common interventions include painted curb extensions to slow traffic and shorten pedestrian crossings, temporary bike lanes for safer cyclist positioning, and pedestrian plazas that reclaim excess road space. Creative crosswalks and pop-up markings increase pedestrian visibility, while enhanced lighting improves safety. This approach allows for real-time experimentation and community feedback, making it easier to identify what works best in specific contexts. These flexible, quick fixes allow cities to test ideas, prioritize safety, and encourage more sustainable, pedestrian-friendly environments.
- 16.
Smart Totems
The deployment of multifunctional smart totems along the cycling and walking paths in order to:
measuring and monitoring air quality in the district by increasing the number of monitoring points across the City of Cagliari and expanding the range of detectable pollutants to include not only PM2.5 but also PM10, O3, NO2, and SO2;
collecting solar energy through vertically integrated solar cells, thereby reducing CO2 emissions by approximately 300 kg per year for each totem, based on Italy's energy production mix;
providing illumination during nighttime;
supplying power for e-bikes and electric kick-scooters;
offering free Wi-Fi connectivity;
serving as an information point for mobility issues and daily events in the city and district.
- 17.
Improvement of the St. Elia local market
The plan involves establishing public urban gardens near the local market where operators, who also sell in the market, will cultivate local fruits and vegetables. This initiative supports a short food supply chain, strengthens the local food system, and builds trust in food quality among residents. It also aims to raise awareness of local traditions among younger generations and offer tourists an authentic taste of local cuisine. Access to the gardens will be free, governed by a service agreement between the City of Cagliari and local market operators or private citizens. Agreements will also allow residents from diverse cultural backgrounds to grow products not available in the Sant’Elia market, promoting a cultural exchange through food. Additionally, the project proposes the creation of a community kitchen and food hub, “Assaggia San Bartolomeo”, transforming the market into a space for cooking, dining, and tasting. Operating daily, the hub will enhance social ties and community collaboration. The hub and gardens will foster a sense of belonging and integration, supported by social activities that encourage community cohesion. Events at the hub will address community issues, celebrate food cultures, and combat food waste. The hub’s role will be further reinforced through partnerships with local schools and universities, offering activities that promote cultural appreciation and social engagement. Finally, the hub will serve as a social and culinary point of connection for residents using nearby sports facilities or passing through on bikes and scooters.
- 18.
Linear green
The proposed solution aims to enhance connectivity and integration with the surrounding areas. The linear green spaces have several important objectives aligned with the ecosystem services they provide, including:
Enhancing the visual experience of the area, ensuring a level of visual complexity that increases the enjoyment of green spaces;
Strengthening ecological corridors to promote territorial and ecosystem continuity;
Reducing fine dust and pollutants in the atmosphere, as these green surfaces serve as effective physical, chemical, and physiological filters against harmful airborne particulates;
Establishing a barrier to mitigate noise pollution generated by vehicular traffic.
- 19.
Green Areas
We have previously addressed the presence of uncultivated and vacant spaces surrounding the neighborhood, highlighting the necessity to transform these areas into functional spaces through urban forestry initiatives. These green spaces can serve as multifunctional mediation areas, both urban-territorial and social, fostering community engagement among residents and beyond. Opportunities presented by the development of sports facilities to the north of the neighborhood is the implementation of green roofs on the four football fields, featuring drought- and salinity-resistant macrothermal species. It is noteworthy that this area once hosted salt marshes, making such vegetation particularly suitable. Incorporating microthermal species, known for their resilience against pathogens and foot traffic, would enhance eco-compatibility and cost-effectiveness in maintenance. This type of vegetation cover offers several advantages, including the ability to irrigate with treated wastewater, given its high salinity resistance. A collaborative relationship could be established with nearby residential buildings, where the green spaces would provide various ecosystem services, while the residential community could supply adequately purified water for irrigation.
- 20.
Green roof and green wall
The redevelopment of the St. Bartolomeo district aims to provide various ecosystem services. To align with the environmental needs of the community (comprising residents, commuters, and workers) the study is approached at multiple scales, including territorial, neighborhood, and microscale levels. Green roofs and facades are particularly relevant at the microscale. In this context, flat roofs will be transformed into green roofs to enhance building insulation and facilitate outdoor activities related to horticulture, gardening, and the cultivation of pollinator species, such as beekeeping. This approach embodies a perspective that transcends anthropocentrism and promotes the establishment of ecological networks. Green walls will serve dual purposes:
Providing insulation for living spaces and contributing to energy savings, while also mitigating the landscape discontinuities created by the new neighborhood's construction;
These walls will effectively address the interruption of the skyline formed by the heights of the new buildings, harmonizing the view with the backdrop of St. Elia’s hill.
- 21.
Rain garden
Another key design feature involves the implementation of rain gardens. These gardens, integrated along the main “slow” road infrastructures such as cycling and pedestrian paths, contribute significantly to achieving essential ecosystem objectives. Rain gardens consist of sunken, draining areas populated by plant species that can withstand both drought and temporary root asphyxiation caused by water stagnation during heavy rainfall. These depressions effectively collect and manage water runoff from adjacent impervious surfaces, thereby minimizing disruption to vehicular traffic.
The functions of the rain gardens can be summarized, though not exhaustively, as follows:
green Barrier: they serve as a green buffer surrounding the cycling and pedestrian paths, providing a clear separation from other road infrastructures. This green component not only delineates the pathway but also ensures adequate visibility for both pedestrians and cyclists, enhancing safety;
phytoremediation: the water collected from impervious surfaces often contains significant pollutants. Therefore, the selected plant species for the rain gardens will also play a crucial role in phytoremediation—either inactivating or retaining these harmful substances within their tissues.
- 22.
Mini static bio stabilization plant
Plant for the production of soil conditioner/fertilization obtained through Static Bio stabilization of agricultural residues/by-products and animal manure. The heap does not need to be turned over and a special enzyme (patented) to which earthworms are added. This enzyme has the ability to prevent the proliferation of bad odors. In the heap just described, residues from “agriculture” can be used, but not fish stew: with the heap of fish stew, a special film for domestic use can be obtained.
- 23.
Water houses
These are Pay-as-you-go water dispensers consisting of a prefabricated structure housing activated carbon filters, cooler/gas bank, CO2 cylinder exchange system, CO2 cylinders, electronic display, coin box, pump to regulate water pressure.
- 24.
Aquaponic plants.
These are a middle ground between hydroponic plants (for vegetable and vegetable production) and aquaculture plants (fish production). They usually consist of tanks of water filled with fish in which polystyrene/plastic plates are placed with holes in them for the roots to draw nutrients directly from the water. The presence of fish serves to purify the water and their feces constitute nourishment for the plants.
Three additional non-tangible actions were identified during the process in order to encourage citizen engagement and foster greater citizen participation.
- 25.
Grow it yourself
Grow It Yourself is an initiative aimed at encouraging the cultivation of products for the table in residents’ balconies, terraces, gardens, and urban gardens. A series of digital workshops and monthly "ask the expert" sessions are planned to provide new farmers with the tools and knowledge necessary to succeed in the new activity. In addition, social eating events will be organized once a month, during which it will be possible to share the products of your own work.
- 26.
Business Mentoring
Business mentoring is a program aimed at supporting local entrepreneurs, promoting sustainable economic development, and creating new job opportunities. It offers a support program for both new and experienced entrepreneurs to start, grow, and renew innovative and environmentally friendly businesses. It provides personalized consulting services to help entrepreneurs achieve their growth objectives.
- 27.
Eco-friendly Citizens
Eco-friendly Citizens is a program designed to support local communities in becoming more sustainable by providing them with tips to reduce waste and consumption of energy and water. Additionally, they will be guided in choosing products that are as environmentally and socially sustainable as possible.
3.5. Definition of the integrated scenario
To define the integrated scenario, a further, and final, meeting was organized, in order to choose the localization of the different projects and to design the new district landscape. This phase was critical to ensure that planning solutions were effectively integrated, otherwise they risked exacerbating the neighborhood’s isolation rather than promoting connectivity.
More specifically, the neighborhood was envisioned as a hub, serving as a “trait d'union” that connects the entire residential area to key territorial infrastructures - currently the very elements that delineate and segregate the neighborhood.
With this vision in mind, the linear green has been concretized in a new tree-lined corridor traversing Via F. Alziator, the neighborhood’s main street, transforming it into a vibrant green promenade that connects to services associated with the St. Elia’s guide project and the Cagliari waterfront (Figure point 1). This diagonal corridor will intersect with access routes leading to the St. Elia promontory and Cala Mosca. To the north of the small neighborhood park, named after the esteemed historian F. Alziator, pathways will branch out towards sports facilities and a designated canoe launch and anchorage. This launch, planned at the entrance of the ancient canal that once fed the salt pans at the base of the Lazzaretto, is situated near the university’s biology faculty, which has become somewhat isolated but was historically an integral part of the San Bartolomeo neighborhood.
The area between St. Elias Market and where the temporary stadium currently stands (Figure point 2) will be the hub of the neighborhood after the new stadium is built. There will be a significant influx of people attracted by sports, recreation, commerce and leisure activities. A Co-working facility will be built here within a multifunctional structure comprising:
Co-working/hub for digital start-up with spaces and workstations with ample light sources and common areas (to encourage contamination between people with different experiences), these environments will be partially separated by hydroponic/aquaponics systems. There will also be areas for relaxation and physical activity with sports equipment from which energy can be produced.
Laboratory for smart cities, urban agriculture - a sort of “Think-Thank” formed by agronomists, engineers, architects, planners, experts in public procurement/partnerships/concessions, researchers, representatives of the productive world and administrators to redefine new parameters and solutions for the arrangement of cities and its relationship with the territory.
For the spirulina production plant have been identified two suitable sites: an unused area between Borgata S.Elia Street and Ferrara Street (
Figure 2 point 3), where there will be other initiatives, where horizontal photo blasters will be placed and the production can be sold on site in the producers' market; the Nervi Pavilion (Figure. 2 point 4), a former salt warehouse from the 1950s, newly restored and set in a park of about 2 hectares between the St. Bartolomeo canal and Su Siccu. There will be areas for refreshments and physical activity. This intervention is part of a larger recovery project that includes the Bonaria shoreline, Su Siccu harbor, St. Elia waterfront, Parco degli Anelli and the Lazzaretto. Being located on a quay, the pavilion represents the most suitable location for algae plants because they have in common the element of water (particularly seawater), the presence of the sun, and in addition there is the advantage of the large influx of tourists and citizens. Vertical and horizontal photo bioreactors can be placed inside the Pavilion, while horizontal ones can be placed in the park.
The area between Salvatore Ferrara street and Borgo St. Elia street (
Figure 2 point 5) will be an extension of the physical market of St. Elia, where it will be possible to have moments of meeting and social interaction, taste 0 km products, urban agriculture and the adjacent garden, enjoy local and seafood dishes. Given the lack of space in the St. Elia market location, in this area will be located food service of the products of the urban garden, fish farms from aquaculture/aquaponics and superfood from the seaweed plants. It can also be set up as a delivery for the sale of food and a take-away for the dishes prepared with resources from the urban area of the individual protections. Waste produced in the restaurant/take-away and food box activities can be conveyed to a designated space in the chosen area or directly to the wet waste platform in the ecocentre.
In the area between Vespucci Street and Fiorelli street (
Figure 2 point 6), currently unused, will be implemented:
eco-sustainable gymnasium, the equipment will be placed outdoors and will allow energy to be produced through use by the athletes;
canoe anchorage, for those who wish, it will be possible to use this type of boat to do sports activities in the St. Bartholomew Canal. Buffer strips may also be built here (Fig. 2 point 7);
The inclusion of buffer strips along major road axes would allow a decrease in noise pollution and CO2 storage, as well as make adjacent public spaces safer.
Finally, several services will be distributed in the neighborhood as shown in
Figure 2: draining pavements, to avoid soil sealing (point 8), mini static biostabilization plant heap of plant by-products (point 9), water houses (point 10), hydroponic systems (points 11), aquaponic plants (points 12), eco compactors (points 13).
The final result of the participatory planning project was elaborated in a 3D view, as shown in
Figure 3, where today's situation of
Figure 1 could be compared with the planned one.
The participatory planning approach described doesn't face the operative phase, that is the decision of the priorities according to financial, bureaucratic and social preference boundaries. The authors intend to explore these aspects further in a subsequent work aimed to define a multicriteria analysis as decision support tools for the administrations.