Green City Guidelines

Welcome to this 2020 version of The Green City Guidelines – a timely update to support nature in cities.







The ‘Green City Guidelines’ project is an internationally targeted initiative that aims to provide practitioners and decision-makers with the essential information they need to understand and communicate the benefits of urban green space or more accurately green infrastructure.

The purpose of this project is to bring this information more into the mainstream in a form that is immediately accessible, yet at the same time supported by the evidence-based substance that practitioners globally need to implement successful green infrastructure responses. The Green City movement has in its heart the belief that the green element is critical to the long-term functioning of healthy, successful, liveable urban spaces.

It is essential that the true value of urban green space is globally understood and that decision-makers have the tools to guarantee its position.



These guidelines are written to provide a wide range of professionals with the stimulus to ask ‘how green is my city?’
It provides tools in the form of practical pointers that show how the contribution of green infrastructure can be enhanced for the benefit of all. This applies both now and for future generations. It is written in the knowledge that the term ‘green city’ has a range of meanings but deliberately focuses on the physical, living green, plants as well as green spaces. The plant features are the elements that underpin the rest of the settlement and can deliver those essential ‘ecosystem services’
that are our life-support systems.

“Ecosystem Services” is a term to describe any beneficial function provided by green space that would otherwise require a technical response (flood defence, air quality, countering the urban heat island) or that offers a cultural or other benefit (e.g. biodiversity or aesthetic/heritage benefits). Although in some sectors the term ESS meets with disapproval if it is considered to make the assumption that nature is here to serve humanity instead of having equality in the hierarchy of life, it does provide a uniform terminology, and is an important concept for securing investment in green space.

IUCN’s Global Water Programme decided to create this diagram to emphasize the important relationship between ecosystem services and the components of people’s wellbeing. This infographic highlights the layers of linkages, demonstrating the extent to which livelihoods are dependent on the sustainability and health of ecosystems, and the variety of services they provide for free” James Dalton, IUCN Director Global Water Programme.

These guidelines do not seek to provide all the answers. This site offers case studies, references, and guidance relating to those subject areas where green infrastructure plays in the successful functioning of the human urban environment.

Green city principles

The Green City Guidelines are founded on the principles of the Green City philosophy. This is an international approach that places green space at the centre of development and regeneration, on a par with red, blue, and grey on the masterplan and in the design process. It uses evidence-based arguments to highlight the importance of green to city form and function.

The Green City principles position ‘living green’ as a fundamental solution to many of the challenges of contemporary life – from stress, burn-out, or obesity to climate-change preparedness. It argues that investment in green infrastructure is repaid many times over in terms of the benefits it brings.

There are a number of key areas in which green infrastructure offers quantifiable benefits. These icons are used throughout the site to identify benefits that relate to each topic. 


Quality green infrastructure increases house and office values (either rental or freehold). It provides a more attractive environment for inward investment and draws additional visitors to a city.


Residents and workers are happier and healthier when they live and work in green surroundings. There are psychological benefits – it is innate in our character to be more at ease in natural environments rather than artificial spaces – and there are physical benefits, such as shade, air quality, and the increased likelihood that we will take healthy outdoor exercise when we have access to green space nearby. Improved health results in lower costs for the health-care sector, benefits the economy, and leads to enhanced human well-being.

Social interaction

Green and nature-filled environments encourage people to spend more time in outdoor spaces which in turn increases the rates of social interaction and mixing. Valuable in all situations, this is especially important in multi-cultural communities where barriers of ignorance and distrust can lead to real conflict. Green space and what can be done in it (from growing food to fishing to flying kites) is also an enabler of inter-generational social relationships. Building stronger communities in this way improves social  cohesion and helps to bring down the social costs of crime.



Bringing green into the city introduces and encourages diverse plant and animal communities. Green roofs and walls, allotment gardens, parks, private gardens, street trees can all provide habitat for thriving ecological communities and help to boost biodiversity in the city. Linked to this is urban agriculture which has a part to play in feeding the cities of tomorrow and making them more resilient to external forces such as transport costs, crop failure in distant regions, and political instability.


Water management and climate change resilience are very closely linked and relate directly to the management of the urban systems. A range of ‘Sustainable Urban Drainage System’ (SUDS) responses are increasingly implemented by water companies and communities who are seeking to respond to the challenges of increased incidence of extreme rainfall events. SUDS solutions offer considerable cost advantages over engineered solutions, as well as providing amenity areas for wildlife, recreation and even food production.

Climate and pollution

‘Living green’ introductions into cities, such as street trees, green roofs and walls, parks and gardens all contribute to moderating the impacts of the urban heat island effect which is recognised as a significant cause of premature death in cities. The shade and air-cleaning benefits of urban greenery have an enormous cash-value for a city in improved health of residents.