NBSI

The 3+30+300 Principle

The 3+30+300 Principle for Healthier and Greener Cities

The 3+30+300 in brief

Urban forests provide a wide range of essential benefits. Current global challenges, such as climate change, environmental degradation, and public health challenges (such as the recent COVID-19 pandemic), have resulted in increased awareness of the importance of urban trees and green spaces.

While situations will always be complex and different, and guidelines are not written in stone, NBSI’s co-director Cecil Konijnendijk launched a new rule of thumb for urban forestry and urban greening in early 2021: the 3+30+300 principle. This guideline or rule of thumb focuses on the crucial contributions of urban trees and other urban nature to our health and wellbeing, as well as climate change adaptation. It also recognises that we have to consider many different aspects of the urban forest in order to make it accessible to all. The principle has as a key ambition to let urban forests and other green spaces percolate into all of our living, working, and learning environments. At the same time, it is straightforward to implement and monitor – and easy to remember. The rule of thumb provides clear criteria for the minimum provision of urban trees in our urban communities by setting the following three minimum requirements:

  • 3 mature trees from every home
  • 30 percent tree canopy cover in every neighbourhood
  • 300 metres walking distance from the nearest high-quality public park or other green space

The 3+30+300 principle is already being used by hundreds of municipalities across the world. We at NBSI can support the implementation of the 3+30+300 principle by assisting with the development of policies and strategies, as well as through workshops, training, and inspirational talks. To further support these implementation efforts, a range of international and Nordic resources has been developed and is made available below.

Additional resources and further reading on the 3+30+300 principle

For an up to date and internationally curated overview of the principle, including background, rationale, and real world applications, visit the official website https://330300rule.com.

In a Nordic context, extensive applied work has been carried out within the Yggdrasil – The Living City initiative. A comprehensive 3+30+300 Handbook, including practical guidance, methodological clarifications, and frequently asked questions, has been produced as part of this work. The handbook is intended to support municipalities, planners, consultants, and decision makers in implementing the principle in diverse urban settings.

The handbook, together with additional reports, background material, and an introductory video explaining the principle, is available at https://tradkontoret.se/yggdrasil/

These resources complement each other and provide both an international and a Nordic evidence based foundation for applying the 3+30+300 principle in policy development, spatial planning, and urban nature management.