Urban Sustainability in Europe — Glossary of key terms and concepts

Page Last modified 29 Jul 2021
19 min read
This glossary provides definitions of the key terms and concepts used in the EEA’s recent work on urban environmental sustainability, including in the following reports and other outputs:

Definitions of key general terms and concepts are provided, followed by definitions of specific terms used as part of the EEA’s conceptual framework for urban environmental sustainability.

General glossary

Barriers (to urban environmental sustainability transitions)

Difficulties that may be preventing some cities from reaching their sustainability potential or from overcoming long-standing economic, institutional and cultural challenges leading to suboptimal environmental outcomes and preventing more radical change from taking place.(Based on EEA, 2020.)

Building blocks

Key qualities that contribute to urban environmental sustainability. Depending on the context and enabling factors, different building blocks will be the inputs required to transition towards urban environmental sustainability.

One of the four main components of the EEA’s conceptual framework for urban environmental sustainability (Lenses, Context, Enabling factors and Building blocks).(Based on EEA, 2021a, 2021b.)

Circular economy

A model of production and consumption that aims to maintain the value of products, materials and resources for as long as possible by returning them to the product cycle at the end of their use while minimising the generation of waste. (Based on European Parliament, 2018.)


A large and densely populated urban settlement. A city is defined in relation to a political level (administrative boundary) and a densely populated ‘urban centre’ (population > 50 000). (Based on EC, 2012 and EC, 2016a)

Closing the loop

A circular model of resource management in which products, materials, built assets and land are kept in use while maintaining their value. It also means minimising waste generation. (Based on EC, 2015.)


The additional benefits above and beyond the direct benefits intended from the main action or measures to improve urban environmental sustainability. Sometimes referred to as ‘multiple benefits’ or ‘synergies’. (Based on EEA, 2019.) 

Compact city

One of a range of terms describing formations of cities that are used in the literature and by different organisations. Compact cities have a range of potential benefits, including dense development patterns, better accessibility to local services and jobs, short intra-urban distances and public transport systems that make positive contributions to the efficiency of infrastructure investments, reductions in energy consumption and CO2 emissions, knowledge diffusion and economic growth.

This concept aims to provide disaggregated perspectives to aid analysis rather than a holistic model for future cities (Based on OECD, 2020a.)

Conceptual framework (for urban environmental sustainability) 

A way of breaking down the complex concept of urban environmental sustainability into its key components and interrelationships to help provide the EEA with a clear structure for its thinking, including in terms of: 

  • the key components and outcomes that should define a vision of environmental sustainability in an urban context in Europe; and
  • the components required to support the transition of European cities towards a more sustainable future, particularly focusing on urban environmental sustainability.
    (Based on EEA, 2021a, 2021b.)


The range of current and historical physical, social and institutional characteristics that create and shape the setting in which a specific city exists, develops and functions. Each city’s context has a considerable influence on its transition to urban environmental sustainability. 

One of the four main components of the EEA’s conceptual framework for urban environmental sustainability (Lenses, Context, Enabling factors and Building blocks).(Based on EEA, 2021a, 2021b.)

Drivers (of urban environmental sustainability transitions)

Factors that encourage cities to transition to urban environmental sustainability and facilitate some cities to reach their sustainability potential. Factors that lead to positive environmental outcomes and support more radical change. (Based on EEA, 2020.)

Enabling factors

Relatively high-level forces that, based on their level of availability, facilitate (drivers) or hinder (barriers) the transition towards urban environmental sustainability.

One of the four main components of the EEA’s conceptual framework for urban environmental sustainability (Lenses, Context, Enabling factors and Building blocks).(Based on Lee and Klassen, 2008.)

Functional urban area

Consists of a city and its commuting zone. Functional urban areas therefore consist of a densely inhabited city and a less densely populated commuting zone whose labour market is highly integrated with the city. (Based on Dijkstra et al., 2019.)

Green infrastructure

A strategically planned network of natural and semi-natural areas with other environmental features designed and managed to deliver a wide range of ecosystem services (as defined by the European Commission’s communication on green infrastructure — EC, 2013). Green infrastructure is present in both rural and urban settings. In urban areas, many different features may be part of green infrastructure (e.g. parks, gardens, grassy verges, green walls or green roofs) in so far as they are part of an interconnected network and are delivering multiple ecosystem services. These green urban elements (or blue if aquatic ecosystems are concerned) may be found within the city and in its peri-urban area. (Based on EC, 2013; EEA, 2017.)

Green recovery

The outcome of the economic stimulus packages and recovery plans that governments have put in place to bring about a recovery from the COVID-19 pandemic that is both green and inclusive. This will, for example, create opportunities for income, jobs and growth, and at the same time accelerate action on medium- and long-term environmental goals, both national and global. (Based on OECD, 2020b.)


A range of perspectives on urban environmental sustainability that represent priority issues/concerns reflecting the EEA’s environmental remit and that can be used to guide/focus assessment and analysis.

One of the four main components of the EEA’s conceptual framework for urban environmental sustainability (Lenses, Context, Enabling factors and Building blocks).(Based on EEA, 2021a, 2021b.)

New urbanism

An urban reform movement that gained prominence in the 1990s and seeks to promote urban qualities that reformers have been seeking for over a century: vital, beautiful, just, environmentally benign human settlements. (Based on Talen, 2005.)

Nexus/nexus analysis/nexus approach

Nexus— the interlinkages and interrelationships between two or more systems (e.g. food and energy) or policy areas relevant to urban environmental sustainability.

Nexus analysis— the identification and analysis of the interactions, interrelationships and interdependencies among sectors and policies or other interventions.

Nexus approach— the consideration of two or more urban policy areas in order to address a specific urban environmental sustainability problem or to advance a policy objective. By identifying priority synergies, co-benefits and trade-offs, opportunities can be identified for better coordinated and integrated policymaking and action.(Based on; Hoff, 2011; FAO, 2014; ICLEI and GIZ, 2014; UNESCAP, 2016; Lehman, 2018; Magic Nexus, 2018; Rode, 2018; EEA, 2019.)

Quality of life

The achievement of a fulfilled human life in cities. It can be highly subjective and dependent on people’s individual circumstances and comprises both material (e.g. food, water and energy security) and non-material (e.g. equity, freedom of choice, enjoyment of natural beauty) dimensions. (Based on IBPES, 2019.)


The capacity of individuals, communities, institutions, businesses and systems to reduce their exposure to, prepare for, cope with, recover better from, adapt to and transform, as necessary, in response to the impacts of climate change. (Based on Resilient Cities Network, 2021.)

Sustainable buildings

Buildings that have high levels of energy and resource efficiency and reduce environmental impacts across their life cycle. Their users enjoy better health and well-being and productivity gains. In turn this translates into cost savings (Based on EC, 2016.)

Sustainable urban growth

The way in which cities and national governments can foster more growth that protects environmental quality and creates thriving, low-carbon and climate‑resilient communities that promote economic vitality, health, well-being and social inclusion.(Based on EEA, 2020.)

Systemic change 

Sustainable, large-scale changes in complex adaptive systems (e.g. cities) and their underlying structures and supporting mechanisms (e.g. policies, routines, relationships, resources, power structures and values).(Based on Wolfram and Frantzeskaki, 2016.)


An antonym of co-benefits. Disbenefits that arise that have to be weighed up against the direct benefits intended from the main action or measures to improve urban environmental sustainability. (Based on EEA, 2019.)

Transitions (towards urban environmental sustainability)

The fundamental and structural changes in urban systems through which persistent environmental and societal challenges are addressed. (Based on EEA and Eionet, 2016; Ehnert et al., 2018; EEA, 2019.)

Urban accessibility

The ease with which people can reach goods, services and activities and connect with one another. In urban areas, accessibility is considered high when households can reach a wide variety of destinations in a short time and at a low cost per unit of travel.(Based on  Litman 2007; Duranton and Guerra, 2016 ; Rode et al., 2019; EEA, 2021c.)

Urban/urban areas

Areas, including cities but also smaller urban settlements and suburban areas, developed for residential, industrial or recreational purposes. (Based on GEMET, 2021a.)

Urban environmental sustainability

Urban sustainability from an environmental perspective achieved by focusing on environmental issues in urban areas, such as air and water pollution, green spaces providing space for people and nature, biodiversity loss, resource efficiency, and mitigation measures to reduce greenhouse gas emissions and manage the impacts of climate change. (Based on Moir et al., 2014; EBRD, 2016; IBRD and World Bank, 2018.)

Urban form 

A city’s physical characteristics as determined by physical elements, morphology, buildings, open spaces, expectant zones and the transport infrastructure.(Based on Rode and Floater, 2014.)

(Sustainable) Urban mobility

Allowing people and goods to move freely and safely in towns and cities while respecting the environment, which is crucial both for quality of life and for the health of the economy. It involves tackling challenges such as traffic congestion, greenhouse gas emissions, air and noise pollution, health issues, safety risks and security threats.(Based on EC, 2007.)

Urban planning

Urban, city or town planning is the planning discipline dealing with the physical, social, economic and environmental development of metropolitan regions, municipalities and neighbourhoods. The expression ‘urban planning’ covers developing land use and building plans as well as local building and environmental regulations. (Based on Council of Europe Publishing, 2007.)

Urban retrofitting 

Incorporating energy- and resource-efficient technologies and approaches into buildings that also bring co-benefits, such as reducing energy costs and creating healthier buildings for residents. (Based on BPIE, 2017.) 

Urban sprawl

The physical pattern of the low-density expansion of large urban areas into the surrounding agricultural areas under certain market conditions. Sprawl lies in advance of the principal lines of urban growth and implies little planning control of land subdivision. Development is patchy, scattered and strung out, with a tendency to discontinuity because it leap-frogs over some areas, leaving agricultural enclaves.(Based on GEMET, 2021b.)

Urban sustainability

An adaptive process of addressing economic (e.g. economic equity), social (e.g. resilience to climate change impacts), environmental (e.g. reduced air pollution) and governance (e.g. ensuring citizens’ active participation in carrying out urban functions) issues in an integrated way within and beyond urban areas. (Based on UN-Habitat and DFID, 2002; IBRD and World Bank, 2018.)

Urban systems

Multiscale, interdependent, social, natural and engineered systems that affect human and planetary well-being across spatial (local to global) and temporal scales. (Based on Advisory Committee for Environmental Research and Education, 2018.)


Urbanisation is a long-term process characterised by both an increasing share of the population living in towns and cities and the growth of urban areas. (Based on Council of Europe Publishing, 2007.)


Definitions of terms used in the conceptual framework for urban environmental sustainability

Lenses — perspectives in urban environmental sustainability


Circular city               

City in which all product and material streams can be brought back into the cycle after use and become resources for new products and services.(Based on Cramer, 2014.)

Green city                 

City model based on approaches to functional and ecological urban development design that provides healthy and sustainable environments for both natural systems and communities.(Based on McHarg, 1995.)

Healthy city 

City with physical and social environments and community resources that enable people to perform all the functions of life and develop to their maximum potential.(Based on WHO,1998.) 

Inclusive city 

City in which the processes of development include a wide variety of citizens and activities and involve spatial, social and economic inclusion.(Based on World Bank, 2021.) 

Low-carbon city 

City that has achieved or is moving towards achieving low-carbon practices in all aspects, including its economy, daily life (e.g. travel), politics and culture.(Based on C40 Cities, 2015.)

Resilient city 

City in which the capacity of individuals, communities, institutions, businesses and systems is enabled to survive, adapt and grow in response to chronic stresses and acute shocks.(Based on Resilient Cities Network, 2021.)

Enabling factors — relatively high-level forces that, based on their degree of significance/impact, facilitate (drivers) or hinder (barriers) the transition towards urban environmental sustainability


Characteristics, patterns of behaviour and understanding of/attitude to issues shared by a group of people in urban areas and learned by socialisation. All cities have their own specific cultural and historical settings. Actions to achieve urban environmental sustainability need to recognise, adapt to or draw on culture to improve the design and implementation of new policy measures. (Based on Center for Advanced Research on Language Acquisition, 2019.) 

Data and information 

Data are raw, unorganised facts in various forms on relevant issues, whereas information is data processed, organised and/or structured so as to make it useful for forming knowledge on a subject, issue, event or process relevant to achieving the urban environmental sustainability transition.

Accessible, relevant, compatible clearly presented and easy to understand data and information are central for identifying and promoting sustainable urban solutions, and for measuring and monitoring progress towards the urban environmental sustainability transition. (Drawn from Glasgow Caledonian University, 2021.)


Management of public/government money and the process of acquiring funds through traditional (e.g. taxes, public-private partnerships) and innovative (e.g. micro-contributions/crowd-funding, land value capture) financial mechanisms to support green investments and the transition to urban environmental sustainability. Note that financing typically refers to how the upfront costs of building infrastructure, etc., are met, while funding refers to how it is paid for it over its life cycle.

Access to sufficient, sustainable finance from various sources is necessary to develop, deliver and maintain sustainable and high-quality urban infrastructure and services and to support other programmes or actions for urban environmental sustainability transitions. (Drawn from Institute for Government, 2018.)


The interaction between the formal institutions and those in civil society. Governance refers to a process whereby actors in society wield power, authority and influence and enact policies and decisions concerning public life and social upliftment.

Public engagement, soft governance, transparency, accountability and integrated decision-making processes involving all relevant sectors, stakeholders (e.g. civil society platforms) and levels of government is crucial to support urban sustainability transitions. (Drawn from Global Development Research Center, 2021.)


Key insights into urban environmental sustainability processes and their management and options for action held by individuals within a group or among groups. Knowledge supported by the education system, research, innovation, networks and training is essential to identify appropriate solutions to urban environmental sustainability issues. (Drawn from EEA, 2015.)


Tools used to facilitate or support practices, processes and behaviours with different forms and in various areas of technological development, including education, construction, transport, energy, and information and communications.

Technological innovation, and making better use of technology, can facilitate sustainability transitions in governance and various sectors by making urban systems more efficient, reducing resource use, supporting better informed decision-making processes, and monitoring the implementation of relevant policies. (Based on EEA, 2021a, 2021b.)

Building blocks — key qualities that contribute to urban environmental sustainability. Depending on the context and enabling factors, different building blocks will be the inputs required to transition towards urban environmental sustainability.  

(All definitions based on EEA, 2021a, 2021b.)

Adaptive capacity

Urban systems with the capacity to be resilient, adaptive and responsive to a variety of chronic stresses and acute shocks, reducing vulnerability to climate change and extreme events.

Built environment quality

High-quality buildings, public spaces and supporting physical infrastructure, such as water supply, energy networks and transport systems, that are built to last, properly integrated with the wider urban system and effectively support sustainable urban living.

Collaborative and community-led

Community-led and decentralised networks, initiatives and partnerships that foster social innovation and enhance resilience and cohesion.

Ecological multifunctionality

Healthy urban biodiversity, ecology and ecological networks that benefit urban ecosystem services and enhance the resilience of the urban system.

Efficient material use and zero waste

Materials and products used efficiently through reuse and recycling with the goal of eliminating the generation of waste.

Energy efficiency

Energy used efficiently to reduce emissions of greenhouse gases and other pollutants, reduce energy costs for citizens and cities, and help ensure security of energy supply.

Environmental quality

A healthy and clean urban environment, including good water, air, land and soil quality and keeping pollution, including noise pollution, within strict limits. 

Green and blue infrastructure 

An interconnected network of natural and semi-natural areas, green or blue spaces and features that deliver a wide range of benefits to urban citizens while also enhancing biodiversity and helping to restore local ecosystems.

Green economy

An inclusive economy that is low-carbon, resource-conserving, diverse and circular and results in improved human well-being and social equity while significantly reducing environmental risks and ecological scarcities.

Housing quality

High-quality housing stock that delivers good environmental performance and healthy homes for residents.

Integrated planning

Integrated, long-term spatial planning and design that delivers healthy, accessible, compact, economically competitive cities and sustainable, multifunctional urban peripheries that also effectively manage urban sprawl.

Low energy consumption

Low energy consumption and demand from citizens and cities, achieved through pro-environmental behaviours and practices that use less energy.

Participation and empowerment

Empowerment of stakeholders and citizens in relevant aspects of decision-making and knowledge creation through timely engagement and meaningful participation across all sectors of society.

Public open space

Good-quality and accessible public open space for all citizens to help to reinforce local identity and civic pride and support social inclusion, community cohesion, health and well-being.

Renewable energy

A high proportion of cities’ energy needs produced from decentralised renewable sources ranging from small plants to community and household microgeneration produced close to the point of use.

Resource efficiency

Natural resources used efficiently and operating within the limits of the planet to bring about economic benefits and promote healthier lives and job creation.

Social and environmental justice

Justice that protects the most vulnerable and disadvantaged and gives them access to a good-quality environment.

Sustainable mobility

A well-connected urban environment based on public and active transport accessible to all, including those socially and economically disadvantaged.

Sustainable urban agriculture

Integration of sustainable urban agriculture and food systems within cities, including the growing, processing and distribution of food and other products in and around cities. 


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