It might seem obvious to say that: “having trees in development should be the normal and expected thing to happen” but too often a lack of commitment on behalf of whole delivery teams means that trees are lost from proposals one by one. Its good to see eight local authorities grasp the nettle and be proactive about integrated approaches to including trees in street design. The 8Cs (Derby and Derbyshire, Leicester and Leicestershire, Nottingham and Nottinghamshire and more recently Blackpool Council and Cheshire East) are planning to deliver a new design guide that builds on MfS and MfS2.
With the support of the Tree Design Action Group (TDAG) they held a workshop earlier this year to look at how the guide could promote and support the integration of trees and wider contemporary green infrastructure solutions. They explored the key principles of: collaborative design, priortizing walking and cycling, supporting innovation and delivering welcoming, inclusive, resilient and safe places. To make sure including street trees in projects does become the norm 8Cs and TDAG recommended that:
- Design choices for trees should be context sensitive, identifying the right tree species,
- When weighing up benefits value the whole life benefit of the tree. Trees have immediate and wider value. Can use i-tree to assess.
- Realise the opportunity to impact on air quality, reduce flooding, sequester carbon and prevent overheating in urban areas.
- Place trees intelligently and consider integration with footways and carriageway, parking and vehicle speed management, utilities and microclimates.
- Technically – seek space efficient integration with utilities, protect trees, ensure adequately nourished and watered and minimize maintenance.
- Take a joined up approaches when advising developers.
The knowledge base to support integrated approaches is developing internationally with some excellent advice being published by TDAG. Their publication: Trees in Hard Landscapes, A Guide for Delivery, TDAG 2014 includes 30 Case Studies from the UK, Europe, the USA and Canada and some excellent diagrams and sections offering technical design solutions and notes on appropriate species selection.