Sustainable cities, urban sustainability, or eco-city (also “ecocity”) is a city designed with consideration for social, economic, environmental impact, and resilient habitat for existing populations, without compromising the ability of future generations to experience the same. These cities are inhabited by people whom are dedicated towards minimization of required inputs of energy, water, food, waste, output of heat, air pollution – CO2, methane, and water pollution. Richard Register first coined the term “ecocity” in his 1987 book, Ecocity Berkeley: Building Cities for a Healthy Future. Other leading figures who envisioned the sustainable city are architect Paul F Downton, who later founded the company Ecopolis Pty Ltd, as well as authors Timothy Beatley and Steffen Lehmann, who have written extensively on the subject. The field of industrial ecology is sometimes used in planning these cities.
There remains no completely agreed upon definition for what a sustainable city should be or completely agreed upon paradigm for what components should be included. Generally, developmental experts agree that a sustainable city should meet the needs of the present without sacrificing the ability of future generations to meet their own needs. The ambiguity within this idea leads to a great deal of variation in terms of how cities carry out their attempts to become sustainable.
Ideally, a sustainable city creates an enduring way of life across the four domains of ecology, economics, politics and culture. However, minimally a sustainable city should firstly be able to feed itself with a sustainable reliance on the surrounding countryside. Secondly, it should be able to power itself with renewable sources of energy. The core of this is to create the smallest conceivable ecological footprint, while producing the lowest quantity of pollution achievable. All while efficiently using the land; composting used materials, and recycling or converting waste-to-energy. All of these contributions will lead to the city’s overall impacts on climate change to be minimal and with as little impact. The Adelaide City Council states that socially sustainable cities should be equitable, diverse, connected, and democratic and provide a good quality of life.
A sustainable city can feed itself with minimal reliance on the surrounding countryside, and power itself with renewable sources of energy. The crux of this is to create the smallest possible ecological footprint, and to produce the lowest quantity of pollution possible, to efficiently use land; compost used materials, recycle it or convert waste-to-energy, and thus the city’s overall contribution to climate change will be minimal, if such practices are adhered to.
It is estimated that over 50% of the world’s population now lives in cities and urban areas. These large communities provide both challenges and opportunities for environmentally-conscious developers. There are distinct advantages to further defining and working towards the goals of sustainable cities. Humans are social creatures and thrive in urban spaces that foster social connections. Richard Florida, an urban studies theorist, focuses on the social impact of sustainable cities and states that cities need to be more than a competitive business climate; they need to be a great people climate that appeals to individuals and families of all types. Because of this, a shift to more dense, urban living would provide an outlet for social interaction and conditions under which humans can prosper. These types of urban areas would also promote the use of public transit, walkability and biking which would benefit citizens health wise but also be environmentally beneficial.
Contrary to common belief, urban systems can be more environmentally sustainable than rural or suburban living. With people and resource located so close to one another it is possible to save energy for transportation and mass transit systems, and resources such as food. Cities benefit the economy by locating human capital in one relatively small geographic area where ideas can be generated. Having a more dense, urban space would also increase people’s efficiency since they wouldn’t have to spend as much time commuting to places if resources are located close together, which in turn would benefit the economy since people can use this extra time on other matters; like work.
These ecological cities are achieved through various means, such as:
Different agricultural systems such as agricultural plots within the city (suburbs or centre). This reduces the distance food has to travel from field to fork. Practical work out of this may be done by either small scale/private farming plots or through larger scale agriculture (e.g. farmscrapers).
Renewable energy sources, such as wind turbines, solar panels, or bio-gas created from sewage. Cities provide economies of scale that make such energy sources viable.
Various methods to reduce the need for air conditioning (a massive energy demand), such as planting trees and lightening surface colors, natural ventilation systems, an increase in water features, and green spaces equaling at least 20% of the city’s surface. These measures counter the “heat island effect” caused by an abundance of tarmac and asphalt, which can make urban areas several degrees warmer than surrounding rural areas—as much as six degrees Celsius during the evening.
Improved public transport and an increase in pedestrianization to reduce car emissions. This requires a radically different approach to city planning, with integrated business, industrial, and residential zones. Roads may be designed to make driving difficult.
Optimal building density to make public transport viable but avoid the creation of urban heat islands.
Solutions to decrease urban sprawl, by seeking new ways of allowing people to live closer to the workspace. Since the workplace tends to be in the city, downtown, or urban center, they are seeking a way to increase density by changing the antiquated attitudes many suburbanites have towards inner-city areas. One of the new ways to achieve this is by solutions worked out by the Smart Growth Movement.
Green roofs alter the surface energy balance and can help mitigate the urban heat island effect. Incorporating eco roofs or green roofs in your design will help with air quality, climate and water runoff.
Sustainable urban drainage systems or SUDS
energy conservation systems/devices
Xeriscaping – garden and landscape design for water conservation
Sustainable transport, incorporates five elements: fuel economy, occupancy, electrification, pedal power, and urbanization.
Key Performance Indicators – development and operational management tool providing guidance and M&V for city administrators
Sustainable Sites Initiative or SSI,Voluntary national guidelines and performance benchmarks for sustainable land design, construction and maintenance practices. Key areas of focus are soil, vegetation, hydrology, materials, and human health and well being.
Increase of Cycling infrastructure would increase cycling within cities and reduce the amount of cars being driven and in turn reduce car emissions. This would also benefit the health of citizens as they would be able to get more exercise through cycling.
Educating residents of cities about the positive impacts of living in a more sustainable city and why it is important would increase the initiative to have sustainable developments and push people to live in a more sustainable way.
Buildings provide the infrastructure for a functioning city and allow for many opportunities to demonstrate a commitment to sustainability. A commitment to sustainable architecture encompasses all phases of building including the planning, building, and restructuring. Sustainable Site Initiatives is used by landscape architects, designers, engineers, architects, developers, policy-makers and others to align land development and management with innovative sustainable design.
The purpose of an eco-industrial park is to connect a number of firms and organizations to work together to decrease their environmental impact while simultaneously improving their economic performance. The community of businesses accomplishes this goal through collaboration in managing environmental and resource issues, such as energy, water, and materials. The components for building an eco-industrial park include natural systems, more efficient use of energy, and more efficient material and water flows Industrial parks should be built to fit into their natural settings in order to reduce environmental impacts, which can be accomplished through plant design, landscaping, and choice of materials. For instance, there is an industrial park in Michigan built by Phoenix Designs that is made almost entirely from recycled materials. The landscaping of the building will include native trees, grasses, and flowers, and the landscaping design will also act as climate shelter for the facility. In choosing the materials for building an eco-industrial park, designers must consider the life-cycle analysis of each medium that goes into the building to assess their true impact on the environment and to ensure that they are using it from one plant to another, steam connections from firms to provide heating for homes in the area, and using renewable energy such as wind and solar power. In terms of material flows, the companies in an eco-industrial park may have common waste treatment facilities, a means for transporting by-products from one plant to another, or anchoring the park around resource recovery companies that are recruited to the location or started from scratch. To create more efficient water flows in industrial parks, the processed water from one plant can be reused by another plant and the parks infrastructure can include a way to collect and reuse storm water runoff.
Urban farming is the process of growing and distributing food, as well as raising animals, in and around a city or in urban area. According to the RUAF Foundation, urban farming is different from rural agriculture because “it is integrated into the urban economic and ecological system: urban agriculture is embedded in -and interacting with- the urban ecosystem. Such linkages include the use of urban residents as labourers, use of typical urban resources (like organic waste as compost and urban wastewater for irrigation), direct links with urban consumers, direct impacts on urban ecology (positive and negative), being part of the urban food system, competing for land with other urban functions, being influenced by urban policies and plans, etc.” There are many motivations behind urban agriculture, but in the context of creating a sustainable city, this method of food cultivation saves energy in food transportation and saves costs. In order for urban farming to be a successful method of sustainable food growth, cities must allot a common area for community gardens or farms, as well as a common area for a farmers market in which the foodstuffs grown within the city can be sold to the residents of the urban system. Berms of fava beans have been planted at Hayes Valley Farm, a community-built farm on the former Central freeway ramps of San Francisco.
Many cities are currently in a shift from the suburban sprawl model of development to a return to urban dense living. This shift in geographic distribution of population leads to a denser core of city residents. These residents provide a growing demand in many sectors that is reflected in the architectural fabric of the city. This new demand can be supplied by new construction or historic rehabilitation. Sustainable cities will opt for historical rehabilitation wherever possible. Having people live in higher densities not only gives economies of scale but also allows for infrastructure to be more efficient.
Walkable urbanism is a development strategy in opposition to suburban sprawl. It advocates housing for a diverse population, a full mix of uses, walkable streets, positive public space, integrated civic and commercial centers, transit orientation and accessible open space. It also advocates for density and accessibility of commercial and government activity.
The most clearly defined form of walkable urbanism is known as the Charter of New Urbanism. It is an approach for successfully reducing environmental impacts by altering the built environment to create and preserve smart cities which support sustainable transport. Residents in compact urban neighborhoods drive fewer miles, and have significantly lower environmental impacts across a range of measures, compared with those living in sprawling suburbs. The concept of circular flow land use management has also been introduced in Europe to promote sustainable land use patterns that strive for compact cities and a reduction of greenfield land taken by urban sprawl.
In sustainable architecture the recent movement of New Classical Architecture promotes a sustainable approach towards construction, that appreciates and develops smart growth, walkability, architectural tradition and classical design. This in contrast to modernist and globally uniform architecture, as well as opposing solitary housing estates and suburban sprawl. Both trends started in the 1980s.
Individual buildings (LEED)
The Leadership in Energy and Environmental Design (LEED) Green Building Rating System® encourages and accelerates global adoption of sustainable green building and development practices through the creation and implementation of universally understood and accepted tools and performance criteria.
LEED, or Leadership in Energy and Environmental Design, is an internationally recognized green building certification system. LEED recognizes whole building sustainable design by identifying key areas of excellence including: Sustainable Sites, Water Efficiency, Energy and Atmosphere, Materials and Resources, Indoor Environmental Quality, Locations & Linkages, Awareness and Education, Innovation in Design, Regional Priority. In order for a building to become LEED certified sustainability needs to be prioritized in design, construction, and use. One example of sustainable design would be including a certified wood like bamboo. Bamboo is fast growing and has an incredible replacement rate after being harvested. By far the most credits are rewarded for optimizing energy performance. This promotes innovative thinking about alternative forms of energy and encourages increased efficiency.
Sustainable Sites Initiative (SSI)
Sustainable Sites Initiative, a combined effort of the American Society of Landscape Architects, The Lady Bird Johnson Wildflower Center at The University of Texas at Austin, and the United States Botanic Garden, is a voluntary national guideline and performance benchmark for sustainable land design, construction and maintenance practices. The building principles of SSI are to design with nature and culture, use a decision-making hierarchy of preservation, conservation, and regeneration, use a system thinking approach, provide regenerative systems, support a living process, use a collaborative and ethical approach, maintain integrity in leadership and research, and finally foster environmental stewardship. All of these help promote solutions to common environmental issues such as greenhouse gases, urban climate issues, water pollution and waste, energy consumption, and health and wellbeing of site users. The main focus is hydrology, soils, vegetation, materials, and human health and well being.
In SSI, the main goal for hydrology in sites is to protect and restore existing hydrologic functions. To design storm water features to be accessible to site users, and manage and clean water on site. For site design of soil and vegetationmany steps can be done during the construction process to help minimize the urban heat island effects, to and minimize the building heating requirements by using plants.
As major focus of the sustainable cities, sustainable transportation attempts to reduce a city’s reliance and use of greenhouse emitting gases by utilizing eco friendly urban planning, low environmental impact vehicles, and residential proximity to create an urban center that has greater environmental responsibility and social equity.
Due to the significant impact that transportation services have on a city’s energy consumption, the last decade has seen an increasing emphasis on sustainable transportation by developmental experts. Currently, transportation systems account for nearly a quarter of the world’s energy consumption and carbon dioxide emission. In order to reduce the environmental impact caused by transportation in metropolitan areas, sustainable transportation has three widely agreed upon pillars that it utilizes to create more healthy and productive urban centers.
The Carbon Trust states that there are three main ways cities can innovate to make transport more sustainable without increasing journey times – better land use planning, modal shift to encourage people to choose more efficient forms of transport, and making existing transport modes more efficient.
Car free city
The concept of car free cities or a city with large pedestrian areas is often part of the design of a sustainable city. A large part of the carbon footprint of a city is generated by cars so the car free concept is often considered an integral part of the design of a sustainable city.
Emphasis on proximity
Created by eco friendly urban planning, the concept of urban proximity is an essential element of current and future sustainable transportation systems. This requires that cities be built and added onto with appropriate population and landmark density so that destinations are reached with reduced time in transit. This reduced time in transit allows for reduced fuel expenditure and also opens the door to alternative means of transportation such as bike riding and walking. Transportation in downtown Chicago Furthermore, close proximity of residents and major landmarks allows for the creation of efficient public transportation by eliminating long sprawled out routes and reducing commute time. This in turn decreases the social cost to residents who choose to live in these cities by allowing them more time with families and friends instead by eliminating part of their commute time.
See also: Compact city and Pocket neighborhood
Diversity in modes of transportation
Sustainable transportation emphasizes the use of a diversity of fuel-efficient transportation vehicles in order to reduce greenhouse emissions and diversity fuel demand. Due to the increasingly expensive and volatile cost of energy, this strategy has become very important because it allows a way for city residents to be less susceptible to varying highs and lows in various energy prices.
Among the different modes of transportation, the use alternative energy cars and widespread installation of refueling stations has gained increasing importance, while the creation of centralized bike and walking paths remains a staple of the sustainable transportation movement.
Access to transportation
In order to maintain the aspect of social responsibility inherent within the concept of sustainable cities, implementing sustainable transportation must include access to transportation by all levels of society. Due to the fact that car and fuel cost are often too expensive for lower income urban residents, completing this aspect often revolves around efficient and accessible public transportation.
In order to make public transportation more accessible, the cost of rides must be affordable and stations must be located no more than walking distance in each part of the city. As studies have shown, this accessibility creates a great increase in social and productive opportunity for city residents. By allowing lower income residents cheap and available transportation, it allows for individuals to seek employment opportunities all over the urban center rather than simply the area in which they live. This in turn reduces unemployment and a number of associated social problems such as crime, drug use, and violence.
Urban strategic planning
Although there is not an international policy regarding sustainable cities and there are not established international standards, there is an organization, the United Cities and Local Governments (UCLG) that is working to establish universal urban strategic guidelines. The UCLG a democratic and decentralized structure that operates in Africa, Asia, Eurasia, Europe, Latin America, North America, Middle East, West Asian and a Metropolitan section work to promote a more sustainable society. The 60 members of the UCLG committee evaluate urban development strategies and debate theses experiences to make the best recommendations. Additionally, the UCLG accounts for differences in regional and national context. All the organizations are making a great effort to promote this concept by media and internet, and in conferences and workshops. An International conference was held in Italy at Università del Salento and Università degli Studi della Basilicata, called ‘Green Urbanism’, from 12–14 October 2016.
Recently, local and national governments and regional bodies such as the European Union have recognized the need for a holistic understanding of urban planning. This is instrumental to establishing an international policy that focuses on cities challenges and the role of the local authorities responses. Generally, in terms of urban planning, the responsibility of local governments are limited to land use and infrastructure provision excluding inclusive urban development strategies. The advantages of urban strategic planning include an increase in governance and cooperation that aids local governments in establishing performance based-management, clearly identifying the challenges facing local community and more effectively responding on a local level rather than national level, and improves institutional responses and local decision making. Additionally, it increases dialogue between stakeholders and develops consensus-based solutions, establishing continuity between sustainability plans and change in local government; it places environmental issues as the priority for the sustainable development of cities and serves as a platform to develop concepts and new models of housing, energy and mobility.
The City Development Strategies (CDS) addresses new challenges and provides space for innovative policies that involves all stakeholders. The inequality in spatial development and socio-economic classes paired with concerns of poverty reduction and climate change are factors in achieving global sustainable cities. According to the UCLG there are differences between regional and national conditions, framework and practice that are overcome in the international commitment to communication and negotiation with other governments, communities and the private sector to continual to develop through innovative and participatory approaches in strategic decisions, building consensus and monitoring performance management and raising investment.
Social factors of sustainable cities
According to UN Habitat, around half of the world’s population is concentrated in cities, which is set to rise to 60% within a couple decades. The UCLG has specifically identified 13 global challenges to establishing sustainable cities: demographic change and migration, globalisation of the job market, poverty and unmet Millennium Development Goals, segregation, spatial patterns and urban growth, metropolisation and the rise of urban regions, more political power for local authories, new actors for developing a city and providing services, decline in public funding for development, the environment and climate change, new and accessible building technologies, preparing for uncertainty and limits of growth and global communications and partnerships.
Solar Water Heaters – Sustainable water heating abolishing the electric shower.
Biodigestor – decentralized sanitation, energy production and fertilizer – solution for pollution and diseases in poor areas (favelas, reservoir banks occupations).
Conversion of electricity into hydrogen (out of peak hours) and hydrogen into electricity (at peak times) – in hydroelectric and large consumers, improving the return on investment) and reducing the environmental impact of hydroelectricity.
Collection and use of rainwater and reuse of wastewater (treated water) – reduction of floods and better use of water resources. Resulting in a “Resilient City”.
Roof of building and green roof – a garden covering the cement of the city.
“Matas Ciliares” for avenues, streets and roads – each “river of cement” balanced by trees on its sides and central flower beds.
Implementation of urban agriculture on idle land, coverage of buildings, schools, health posts and public squares.
Composting of organic materials, generating fertilizer and recycling of other materials – waste becomes an input with economic value.
Integrated ground transportation – Metro / corridors of bus feeders / minibus feeders runners / parking of vehicles built / bike paths.
Hidrovias (example in São Paulo: Waterways in the Tietê and Pinheiros rivers) – leisure and urban transportation (reduction of traffic bottlenecks).
Cabotage and railways – transport of goods over long distances by cabotage, to coastal cities and via railways, to cities far from the coast
Biofuel for vehicles – reduction of the factor that is the largest emitter of CO2, contributing to global warming.
Empowerment of civil society, via requirement change codes of construction and other laws and funding and voluntary construction of these projects in poor areas of each city neighborhood.
They vary according to the geographical context, the history and the size of the city, but the themes of governance, global warming, energy, waste and transport, environments (water, air, soil, land) as well as biodiversity (renaturation, green weave, urban ecology) are put forward. It is also a matter of producing a habitat and means of transport at affordable costs for all, by facilitating wealth and social and cultural diversity. As early as 1994, they were put in writing by the Aalborg Charter.
The question of the environment appears as major and transversal. It is global (fight against the greenhouse effect and the pollution of the biosphere) and local (recycling of water and waste (including composting / anaerobic digestion), short and sober sectors, soft, clean and safe energies, economy of energy and heating, even a city with positive energy (eg commitment of the city of Perpignan in France), recycling, city without a car, etc.). It is also a question of adapting the cities (those of the hot regions in particular) to the unavoidable impacts of global warming (heat waves and hazards).exacerbated climate and sanitation).
Faced with the problems of periurbanisation and increasing ecological footprint, the classic urban model seems to have reached its limits. There are two trends: to radically change it to produce new ecological cities (eco-cities), or to adapt it with simpler measures.
On the basis of examples already realized, this concept questions communities involved in neighborhood projects (eg eco-neighborhoods) or urban renewal, leading them to reflect on the city’s ” sustainability ” (sustainability for English), that is, its impact on the future, its identity and its ability to maintain itself over time. It encourages a firm, ambitious and non- elitist political and participatory project.
The offer is still very low, and urban planners and architects trained in the application of the principles of sustainable development is still rare, the risk is to see the development of eco-neighborhoods or eco-cities elitist, reserved for richer or designed technocratic.
Some of the conditions of urban transition are of a political and cultural nature, but other conditions are scientific & technical and multidisciplinary. In these areas, tests, certifications and standards writing take time and the world of scientific training and research must also meet the new needs of urban planning stakeholders, in particular management based on scientific principles, and an ecosystem approach to urban trees and urban nature. Scientists are also expected to contribute to assessing the sustainability or sustainability of these cities.
Another limitation has been that the concept of a sustainable (or sustainable) city has long remained poorly defined, and therefore does not have clearly measurable principles, indicators and criteria. As a result, many cities could self-declare as “sustainable cities”.
This is starting to change: little by little researchers, cities and institutions have tested various means of quantifying objective data 5 and wanted to produce useful indicators (for example since 2015 via a new ” ISO 37120 ” standard (Sustainable Development of Communities: Indicators for City Services and Quality of Life) which now includes 46 indicators dealing with the following themes:
Appearance of indicators
Many indicators measure the sustainability of a city:
Fire risk management and civil security
Production and management of solid waste
ICT (Telecommunications and innovation)
Water and sanitary facilities
Of the 46 indicators, some explicitly address environmental issues:
Total electricity consumption per inhabitant (kWh / year)
Electricity consumption of dwellings / constructions per unit area (kWh / m2)
Share of energy from renewable sources (in the total consumed by the city)
Rate of fine particles (PM2.5) in air
Particulate matter (PM10) in the air
greenhouse gas emissions (in t / hbt)
Share of the city’s population with regular solid waste collection
tonnage of waste collected per inhabitant
recycled solid waste
Share of the population served by the sewer system
Share of urban wastewater receiving no treatment
Share of urban wastewater receiving primary treatment
Share of urban wastewater receiving secondary treatment
Share of urban wastewater receiving tertiary treatment (lagooning)
Share of urban served by a drinking water system
Share of urban dwellers with sustainable access to improved water resources
Share of urban dwellers with access to improved sanitation
Domestic water consumption per capita (liters per day).
Source from Wikipedia