Tree or Building
By
2020-06-22
I have been an architect all of my professional career. As an architect, I often encounter challenges, and work with clients who require me, where possible, to identify design solutions to the problems. Trees have been one of the challenges to be worked with. I have just completed a doctorate thesis based on the question, ‘Trees or Buildings: Why can’t we have both’?
During my training as an architect, and developing my own professional practice, trees were an issue that was often a mystery. They were encountered on an increasing basis on the development sites that I worked on. My own architectural philosophy is based on the natural environment informing built form. I regularly worked with arboricultural consultants, whose role was to inform what was possible.
In 2008, I began a journey to more fully understand, and to appreciate trees and their needs. At the time, I was working with the late Rodney Helliwell, the arboricultural consultant, on a range of projects. The conversation we had is below. My own approach is to find solutions to problems. I determined to find out more about trees, and took what was then the AA Technician’s Certificate (now the Level Four Diploma).
Since gaining some knowledge and understanding of a tree’s requirements to function and progress to maturity and longevity, my work as an architect has developed to use trees as a source is inspection and site context for my building designs. In part one, I shall share the though process and in part two I am going to share two case studies I believe this has been achieved.
1. Arboriculturist - It is not possible to place the building on the edge of the canal bank as excavation works could undermine the structural integrity of the bank by disturbing the tree root system that it depended on.
Architect - If a foundation system with minimal excavation could be used, could this enable construction in this position?
Answer - Maybe.
2. Arboriculturist - It won't be possible to locate the floor of your proposal on the ground next to the canal bank as the system of tree roots require essential access to oxygen through a porous surface, and any solid floor on the land would compact the soil and prevent access to oxygen.
Architect - If I could devise a technical solution that located the floor on the canal bank, but prevented compaction, could that work?
Answer - Maybe.
3. Arboriculturist - You cannot build a wall to enclose your building at the canal bank location as the outline profile of the legally protected tree canopies undulates and is not flat like a wall.
Architect - If I were able to create a wall shaped to follow a forecasted canopy outline, could that work?
Answer - Maybe.
The meeting continued in a similar vein, concluding with the agreement that I would design potential solutions to the issues for Rodney to consider as follows:
1. Drill a series of holes along the canal bank around 3m deep and at 3m centres, producing minimal potential disturbance to the structural tree root system. A concrete piling system was proposed to support the perimeter of the buildings external envelope, allowing the existing root system to intertwine amongst the piles.
1. Response: This would satisfy the biological requirements of the tree roots and subject to a structural engineers input would be a satisfactory outcome.
2. If I raised the floor above ground level, say 600mm would that prevent compaction of the surrounding soil and allow oxygen to flow under the ground floor of the proposed building providing adequate access to oxygen?
2. Response: That would be a satisfactory outcome and enable the biological requirements of the tree to function. However, the external landscaping around the building would also need to be a porous material such as gravel.
3. If I made my wall the shape of the outline of the canopy, with concave balcony spaces to allow the canopy to be undisturbed could that work?
3. Response: It could work, but the canopy would still require some pruning in the future as it grew, but this would represent good arboricultural management and would be permitted subject to a planning application.
In part two, I shall share two case studies where buildings were designed in harmony with the surrounding environment including the needs of trees.