A Green Technological Rehabilitation of the Built Environment. From Public Residential Estates to Eco-Districts

Abstract

The environmental quality of the modern city is a central issue in the Italian and international design debate. The pandemic and the perspective of a post-pandemic phase have accelerated the inevitable transformation of the living spaces—indoor and outdoor, urban and domestic—bringing out renewed awareness and new quality requirements. The need to achieve results to limit energy consumption, reduce polluting emissions, promote less land consumption, and conditions of urban resilience is becoming gradually urgent, according to European and national strategic, political and regulatory indications. Space quality requirements, which correspond to different conditions of quality of living, are generally identified in the physical and social accessibility of places and dwellings, in the production and availability of energy from renewable sources, in the availability of green public spaces, and in the opportunity to carry out leisure and sports activities. The paper investigates the transformation of public residential neighbourhoods, highlighting urban and technological design opportunities within the paradigm of eco-district and biophilic urbanism. Two case studies within the INA CASA Plan in Reggio Calabria—Sbarre Inferiori and San Brunello—will be the object of analysis and meta-design transformation scenarios to test with green quality requirements. The scenarios aim to explore microclimatic improvements for the districts, the redefinition of outdoor spaces, the implementations of technologies for clean energy production, and the containment of resources consumption. The object of the contribution goes towards principles of health and well-being of the communities, recognising the urban risk factors implicated in the global pandemic and the need to restore the existing building stock and residential estates. Eventually, the paper suggests a framework of actions, green technologies, and design options to manage those environmental concerns.

1 Introduction

Cities, their sub-systems and elements, human and non-human actors, are the most complex product of human society, due to the coexistence and interpenetration of multiple spheres in a condition of precarious equilibrium. The social sphere, individual and collective, and the goal of well-being are the reason for technological, scientific, and productive progress as well as the unsustainability of our lifestyles, social injustice and inequality. Today, next to the cultural, scientific and academic debate, public opinion has reached a higher awareness of sustainability issues, recognising how global phenomena can affect their daily lives and vice versa. Such awareness has affected also the use and perception of our living spaces: dwellings, neighbourhoods, public and private spaces. Sustainability has today gained widespread attention thanks to the media and the dramatic events of recent years (from the economic crisis of 2008 to the spread of the Coronavirus in 2020 and the energy crisis of 2022). The city is always the core of this debate as a place where to experiment with new forms of design, production, coexistence, and collaboration. The contribution observes the paradigm shift in the attitude of the citizenry, residents of the residential neighborhood, which no longer corresponds to a passive role of consumer or resident of the working class. In this context, the resident is aware and well happy with his active and proactive role in the policy and decision-making process concerning environmental and urban sustainability, with an increase in direct participation.

Today, the resident is a citizen, is involved and participates in decisions and actions, and can benefit from them. The influence of design for social innovation has played a part in creating socio-technical ecosystems and supporting individual capacity building (cf. Sen). The recognised need to move towards more sustainable lifestyles has opened up new horizons for ecological and green design for the redevelopment and retrofitting of existing buildings, improving energy performance, and environmental well-being, and shared energy production.

This paper aims to outline the salient points of this debate, identifying the challenges posed to contemporary living and cities, focusing on public housing estates. Sustainable development issues and goals are increasingly specific, requiring sophisticated design solutions. The contribution, therefore, reflects on green strategies, processes, and technologies that can positively affect social and environmental well-being, supporting the progress of both spheres.

2 Challenges of the ‘Modern City’

The contemporary city is often mistreated and scapegoated in the discussion on the unsustainability (physical, social, and environmental) of urban systems. For the same reasons, it is also a privileged object of research applied to its multiple spheres and dimensions falling within the urban and built environment. However, this distinction is not sufficient to frame the daily activities, flows of people, goods, and services which cut across the spaces and functions of the city. Similarly, the sustainability challenges facing the city cannot be resolved exclusively in one dimension or another, as buildings—residential and non-residential—and their urban surroundings must be considered as a unicum, held together by multiple cause-effect relationships. Energy consumption, waste production, clean air, green spaces, and social cohesion are just some of the main concerns of contemporary times. These can be addressed through process, design, and technological innovations applied both to the urban environment, mobility, and public spaces and to the built environment, buildings, and housing.

The contribution distinguishes two spheres of environmental concerns: the infrastructural one, related to energy, services, and mobility flows; the construction sector; and the energy cost of buildings in operation. Both have specific issues of energy consumption from non-renewable sources and the production of harmful emissions and different types of waste (UN 2020). In terms of emissions, consumption of resources and production of construction waste, new construction sites have a huge impact on the environment, particularly due to the use of traditional wet construction technologies.

While these structures cannot be reused at the end of their life cycle—due to their many components, such as bricks and plasters—on other hand, they have a wider potential for maintenance, managing to increase the life cycle of the building.

2.1 The Post-pandemic Perspective and Beyond: New Scales, Needs and Requirements

The post-pandemic perspective has accelerated both the processes of ecological transition of the built environment and public awareness. During the first lockdown, the decrease in industrial production and the use of fossil fuel transport drastically improved global air quality (WMO 2021). Aerosols from these activities have the most dramatic effect on human health and air quality and are the biggest factor in the amount of PM2.5 in densely populated areas (WMO 2021). These health effects are a major factor in the fatal risk of COVID-19 infection. This environmental and health awareness has motivated different choices related to lifestyles, quality of space, and mobility, resulting in a redefinition of the urban and built environment at the residential and neighbourhood scale. Public spaces, mobility, and the energy grid are pivotal.

The role of urban public space has regained the centre stage in the last 10 years to pursue ecology, cohesion, and democracy (Errante 2019, 2021). Even during the pandemic crisis, public and semi-public spaces such as squares, courtyards, and places of mobility have undergone major perceptual, spatial, and infrastructural transformations. Mainly to make way for pop-up bike lanes and wider walkways to allow social distancing. The EU and individual governments have allocated funds and launched policies to transform road layouts and integrate technology and equipment to encourage individual, non-fossil, and public sustainable transport, which was already a priority for many political agendas (Lozzi et al. 2020). On the other hand, the recent geopolitical situation and the energy crisis are also encouraging containment of consumption and energy self-sufficiency. The production of clean energy and its off-grid accessibility with innovative distribution processes have been experimented with collaborating peer-to-peer micro-grids. The neighbourhood is the place of such cultural and technological innovations, with the active participation of residents. Here, collective self-consumption groups, known as renewable energy communities, are committed to producing and sharing the energy they need. A framework of new sustainable needs and requirements is emerging, with opportunities for technological, design, environmental, economic, and social innovation.

2.2 Design Opportunities Towards Eco-Districts

The design opportunities the paper discusses relate to the political role of architectural, technological, and environmental design in responding to the real needs of communities. These are now told through the perspective of sustainability, but they are issues that have always concerned the dynamics of design and refer in particular to access to essential services and their quality. Even today, these quality objectives must be sought in the dimension of the home, the building, and the residential neighbourhood, especially in contexts of physical and social marginality. Here the concept of environmental quality of living spaces refers to two conditions: the physical space, indoor and outdoor, of the home and the public spaces around it; and that of limiting consumption, even before emissions. In contexts where access to energy services is subordinate to the economic capacity of individuals and families, the production of accessible, clean energy and savings from reduced consumption are fundamental objectives to be achieved. Environmental quality can therefore be pursued through a reorganization and re-functionalization of living spaces, integrating energy efficiency and production. The shared management of these environmental technologies drastically affects the economic and social sustainability of the communities that benefit from them.

Biophilic urban and city design. Biophilic design is an approach that holds principles of good design at the building, site, city, and regional scale, including natural elements that humans should have to evolve with (Beatley and McDonald 2021). Beatley and others argue that exposure to green space produces several benefits for the individual mental and physical health. Also, the biophilic design uses the natural asset provided by the context in an environmentally sustainable way by:

• Protecting and enhancing the natural systems and green infrastructures from climatic events, ensuring the provision of essential services;

• Moderate air pollution and balancing microclimate through vegetation that provides cooling, evapotranspiration, shading and reduction in urban flooding. Green rooftop alone may dramatically contribute to the reduction of urban temperature;

• Allow native biodiversity to adapt and shift as climate changes, according to an extensive and diverse network of parks and green spaces;

• Help cities to become more self-sufficient in times of resource scarcity such as oil, food, or water;

• Encourage a healthier lifestyle, resulting in overall energy saving.

The biophilic approach can be described as an outdoor-oriented design at the neighbourhood scale, with benefits reaching the regional since the individual level (Fig. 61.1).

Fig. 61.1

Overview diagram of possible morphological actions that can be applied, at different scales, by integrating green technologies

Green technologies for energy saving and production. The concept of green technologies is closer to the definition of eco-tech or eco-technologies. The green paradigm is declined through wise use of materials from renewable, recyclable, and reusable sources adopting innovative and alternative construction technologies that cannot damage the environment. A building that meets these criteria can be considered green (Fig. 61.2). According to several authors, the criteria of ecological design should be oriented to:

Fig. 61.2

Diagram of the variety of sustainable actions and green technologies that can be adopted at the city block scale to improve energy performance and urban resilience through: heat island effect mitigation systems, clean energy production systems from renewable sources, local production and cultivation, with urban gardens

• The correct planning of the intervention and its impact on the social, economic, and environmental spheres; the flexibility of the interventions according to scenario steps; and reuse existing buildings (Bergevoet and van Tuijl 2016);

• Aim at circularity in the production, execution, and management stages (Errante and De Capua 2021);

• The improvement of the overall environmental quality.

In this sense, we can say that the main interventions are related to the improvement of energy performance. Similarly, it has been mentioned how the biophilic approach can intervene on microclimate shading and cooling while reducing energy demand.

Nevertheless, greenery and eco-technologies include energy production and storage systems that can be used to meet these needs. The most common solutions use solar energy to produce hot water and electricity, but there are also kinetic energy production technologies integrated into the pavement of public spaces.

Technological advances in this regard have enabled the development of new scenarios for off-grid energy production and sharing, such as energy neighbourhoods and communities that, through specific public–private partnerships, provide direct access to energy from renewable sources at a reduced cost or even profit.

3 The Research Perspective and the Case Studies

The broader framework of environmental regeneration represents two aspects of technological regeneration for the residential areas capable to address:

• physical and social marginality;

• structural and technological obsolescence of the buildings;

• inaccessibility to essential services for residents.

These contexts are heterogeneous, requiring multi-scalar and multi-criteria methodological approaches. The recent literature on housing shows a hybridization between the urban design and housing dimensions, highlighting their collaboration at the neighbourhood scale. The Public Space-Public Life approach (cf. Gehl) has evolved into the Soft City paradigm (Sim 2019), oriented towards urban density, accessibility and quality of public spaces in neighbourhoods, with an environmental role. UN-Habitat’s “Public Space Site-Specific Assessment—Guidelines to Achieve Quality Public Spaces at Neighbourhood Level” (2020) provides an analytical tool to understand the context and act accordingly. The concept of physical and relational proximity has led the neighbourhood to be considered a minimal ecological unit, where accessibility is the result of a space-time-opportunity equation. The topic of “15 minutes city”, in Italy well-argued by Manzini (2021) is something already seen and experimented with in the Super-Illas of Barcelona (ES), where urban regeneration, public spaces, mobility, and energy production are part of a wider concept of functional proximity.

Based on these considerations, the research was applied to two case studies of meta-design experimentation, selected in the context of the INA Casa Plan. The cases represent aesthetic, formal, and technological qualities, as a further opportunity to rethink the existing (Di Biagi 2001). The two selected neighbourhoods are located in Reggio Calabria, in the southern and northern suburbs of the city. They present very different spatial characteristics, the common aspects concern:

• the distance from the consolidated historic centre, less than 4 km;

• the coverage ratio and the presence of potential public spaces;

• the wet construction technology, with reinforced concrete framed structure, concrete floors, and brick infill;

• the overall good structural condition;

• the lack of central heating systems and lifts.

At the type-morphological level, the urban layouts are different. Sbarre Inferiori (1959–1964) has 26 buildings of five floors with five aggregate types. The linear aggregations are made of 2–4 modules, of two 75 m² units each. The three-lobed typology has hexagonal elements, with 95 m² apartments each. The buildings were originally on pilotis, no longer visible due to successive modifications. The residential public spaces are neglected, with no provision for outdoor activities. San Brunello (1950–1954) consists of a long building with four floors that defines an M-shaped layout and a total of 120 dwellings. Within the bends, there are large green spaces, patios, semi-private gardens, and parking spaces for residents. Ten different dwelling dimensions, ranging from 60 to 138 m², can be distinguished, all with double overlooking, balconies and loggias, while the ground floor apartments have their entrance.

The research, currently in progress, elaborates design scenarios oriented to the integration of green and eco-technologies applied to the building and the external spaces and three functional operations: thickening, addition, replacement. The design criteria address energy containment and the quality of residential and public spaces in the surroundings. The design of the ground, the hierarchy of pathways, and the leisure activities collaborate in the overall strategy of energy efficiency of the entire neighbourhood. The first phase of the research was conducted and concluded on the case of Sbarre Inferiori, with three scenarios.

• 1. Functional additions. A buffer space between the building and the environment is designed according to principles of “technological disintegration”, DfD and remanufacturing. The use of dry technologies, in steel for the secondary structures and bio X-LAM for the add-on units, allow them to be disassembled—as a whole or in the individual parts of the technological system—replaced—according to those proposed by the functional abacus—and re-assembled into new configurations and different places. The life cycle of the additions is extended through the re-aggregation or the disintegration of the elements, to be used as a material bank (Fig. 61.3).

  Fig. 61.3

  

  Functional addition connected to the blind front of the building. Together with nature-based solutions, the design scenario bases its strategy on Design for Disassembly. Edited by: A. Quattrone, 2020—M.Sc. thesis in Architecture

• 2. The thickening of the envelope reduces energy needs and improve building performance. The double-skin façade includes an elevator integrated with a balcony and ramp system externally accessible by the ground floor by a public portico.

• 3. The typological redefinition of the dwellings into smaller ones widens the target of residents and integrate air ventilation cavities as a natural cooling system. Aims at the environmental and energy quality of the neighbourhood (Fig. 61.4).

  Fig. 61.4

  

  The strategy adopts a general greening of the area, while a twofold solution is used for the buildings: the cladding of the four fronts with external thermal insulation and exposed brick cladding; the insertion of the addition aimed at improving the accessibility of the dwellings through the insertion of appropriate ramps, walkways and a lift body. Edited by: E. Dattoli, 2021—M.Sc. thesis in Architecture

The scenarios involve energy production systems from renewable sources, photovoltaic panels and kinetic paving, green technologies and watersquares in public spaces to enhance climatic and environmental resilience. The scenarios are currently under the examination of the resident community for their feedback.

4 Conclusions

The research field of architecture technology is aimed at redeeming its sustainability debt to the natural environment by suggesting green, sustainable solutions to be adopted at the scale of the building and the city, to, directly and indirectly, guarantee greater quality and environmental comfort.

Foreseeing energy alternatives in technological design meet environmental, social, and economic sustainability requirements. The emergence of climate change determines new design needs that can only be addressed through an ecological approach that requires a deeper knowledge of the technologies—urban and building—most appropriate to solve local environmental contingencies. Facing these challenges by starting from the first Italian examples of social housing, such as the INA Casa Plan, represents the closing of a circle for research. On the one hand, to “overcome the theories of urbanism of the Modern Movement to define new ways of reading, interpreting and designing the city” (Guidarini 2018). On the other, to restore centrality to Italian excellence in architecture and construction, even in contexts that have remained oblivious because they are outside of authorial production. INA Casa’s public residential neighbourhoods allow, more than others, to reflect on the indoor/outdoor, built/empty, private/public space relationships at the local micro-scale, concerning the socio-spatial dynamics and environmental fallout of projects to retrofit the existing and regenerate residential spaces (Ottone and Cocci Grifoni 2017).

The ecosystem approach to urban regeneration and building rehabilitation appears necessary today in order to provide alternative, credible, and sustainable responses to the needs for energy efficiency, health and safety in the built environment. The solutions here described do not represent an exhaustive picture of the overall environmental design panorama but highlight the direction of technological evolution towards solutions that integrate nature as a building material, as a mitigation tool, as a form of production, and for bio-chemical processes capable of constituting real energy alternatives. We are witnessing a time of major social, cultural, geopolitical, economic and climate change. In this context, urban transformation and the construction industry play a driving role, which is as necessary to activate investment as it is to support a necessary ecological transition and urban resilience. For this reason, the premise of the research is to understand these solutions in order to apply them to real case studies through a meta-design approach, thanks to which design, technological and performance alternatives can be developed for discussion with communities and administrations.

The research described so far proposes an approach that can be replicated in other urban and geographical contexts, as it is flexible in capturing the peculiarities of the context, thus proposing appropriate solutions from a bioclimatic point of view. Again, in terms of technological choices, there is an ever more pressing need to formulate nature-based, biophilic, and green solutions that better counterbalance the negative effects of climate change on the quality of life and the natural and built environment.