The role of engineered tree pit solutions in nature-positive civil engineering Available to Purchase

Successfully establishing and growing street trees presents significant challenges, and traditional techniques are associated with elevated tree mortality. Moreover, securing appropriate soil volumes for trees is a substantial challenge, particularly in modern street engineering where grey infrastructure is prioritised over tree success. Engineered tree pit solutions can counteract this situation. They enable trees and grey infrastructure to coexist, providing improved rooting environments, load-bearing structural support conforming to engineering specifications and the ability to manage stormwater runoff within one tree pit design. This article presents a literature-informed overview of the current technologies applicable to new-build and retrofit scenarios that integrate street trees and pavements, enabling nature-positive, resilient tree pit designs conducive to tree growth. The focus is on the solutions most commonly employed in practice – structural growing media and crate systems – outlining their constituents, construction and considerations for success. This article informs built environment practitioners, policymakers and researchers on innovations translatable into practical techniques to enhance tree pit design and optimise street trees as multi-functional nature-based solutions.