The 3-30-300 Rule for urban forestry and greener cities was introduced by Cecil Konijnendijk, the Director and Co-founder of the Nature-Based Solutions Institute, in the beginning of 2021.
As an expert, he often got asked by national governments and international organisations for specific guidelines for urban greening. He often declined with the argument that every city is different and that setting transferable targets across various contexts and settings is difficult.
However, given the current climate and public health urgencies, he chose to develop a guiding principle for urban forest programmes and city greening. The rule focuses on the many benefits of urban forests and on the contributions to our health and wellbeing, as well as climate change adaptation.
In its simplicity, each of the three numbers provides criteria for the minimum provision of urban trees in urban areas:
3 tree from every home
30 percent tree canopy cover in every neighbourhood
300 metres from the nearest park or green space
Based on up-to-date research and the work of influential organisations like the World Health Organization, it brings attention to the importance of bringing trees and nature all the way into people’s neighbourhoods, streets, and on their doorsteps in order to capitalise on their many benefits.
In an article for IUCN, Cecil Konijnendijk explains:
“This rule focuses on the crucial contributions of urban forests and other urban nature to our health and wellbeing. It recognises that we have to consider many different aspects of the urban forest in order to be successful. It also addresses the need for urban forests to percolate into our living environments.”
According to Cecil Konijnendijk, implementing the 3-30-300 Rule will help improve and expand the local urban forest in many cities and promote health, well-being, and resilience.
The rule is easy to communicate, straightforward to implement and monitor, and easy-to-remember non-the-least. It can generate interest and support among residents, politicians, businesses, and other key stakeholders, and is a step on the way to create greener, better, and more resilient cities.
Every citizen should be able to see at least three trees (of a decent size) from their home. Seeing green from our windows helps us keep in touch with nature and its rhythms. It provides important breaks from our work and can inspire us and make us more creative.
An example is seen on Frederiksberg, Copenhagen where a tree policy calls for every citizen to see at least one tree from their house or apartment.
Studies have shown a connection between urban forest canopy and cooling, better microclimates, mental and physical health, and possibly also reducing air pollution and noise.
Studies have found that 30% is the minimum percentage of tree canopy cover to ensure that residents benefit in terms of their health and wellbeing. More leafy neighborhoods will encourage people to spend more time outdoors and to interact with their neighbourhoods (which in turn promotes social health).
The European Regional Office of the World Health Organization recommends a maximum distance of 300 meters to the nearest green space (of at least 1 hectare).
Many studies have highlighted the importance of proximity and easy access to high-quality green space, encouraging recreational use with positive impacts for both physical and mental health.
The rule suggests that we don’t always have to think of park-like spaces, but also make use of linear spaces like green avenues that have substantial vegetation, seating, areas to play and exercise, and integration of public space and mobility.