Building Within the Trees
In the context of the current pandemic circumstances and the climate emergency, our lifestyles are gradually changing just as our mindsets and expectations are for the future. Many of us are more inclined to revolve back to the essentials of our human nature and instincts, and living closer to nature is becoming a priority for many of us. Often, this is in conjunction with a choice to inhabit smaller and simpler dwellings which sit harmoniously into their environment. Dwellings with sustainable and innovative designs, as well as self-sufficient properties. And what could be closer to nature than a treehouse?
Building within the trees essentially consists of implanting a new ecosystem into an existing ecosystem, without negatively impacting its primary and former setting. The treehouse is essentially a hybrid between a building and a tree, with its roots, its core, its limbs and its leaves. Just like a tree, the architectural element has various layers and a complex combination and superimposition of elements which need to be carefully considered to achieve a successful ‘transplant’ within the site.
At Millar Howard + Workshop (MHW), we have garnered extensive expertise in developing schemes which achieve exquisite designs for clients who decide to embark on a journey of building their home within trees. Designing a tree house involves a careful analysis of the site, its morphology, and the ecosystem which is already in place. It is crucial to preserve it, rather than interfere with it. The site and its characteristics tend to strongly dictate the design, which is what makes the project unique. We have come to realise that difficult sites with multiple constraints, when considered carefully, generate the most exciting and effective projects. The architecture is induced by trees that have been present on the site for decades if not more, therefore, the rules and the conventions are different from a standard project.
The light, the shade, the shapes, the forms, the spaces, and the views become dependent on the trees. The trees themselves are influenced by the seasons, the elements, and the animals which live in them. This essentially means that the future users of the tree house will inhabit a visibly continuously changing environment; a form of symbiosis with nature, whilst embracing its mood swings. It is an extraordinary living experience. These additional constraints involve a more in-depth design approach. Unlike on standard projects, the site is already populated by fauna and flora which is intended to stay and is preserved alongside the process of construction, and is potentially enhanced after its completion. This exercise of preservation and impact mitigation processes form a large part of the challenge in projects of this nature. So how do we achieve this?
The whole process of the project involves a very close collaboration between the client, the architects, the consultants, the planners and the constructors. All these stakeholders play an important part in understanding the site and telling the story of its future. There is not an ultimate recipe to follow to design a tree house, but prior to the creation of a successful building adapted to the site, there are a number of surveys and studies to be carried out. We have an ardent passion for designing architectural elements which embody their surroundings and we could write infinite pages about the opportunities and challenges in designing a tree house. However, aspects to be considered in doing so can be summarised as follows: arboriculture, ecology, heritage, conservation, planning designations and policies, impact assessments, structural assessment, daylight & shade analysis, sustainability and energy performance, drainage and services, impact on neighbours and views, landscape and screening, accessibility, fire safety and building regulations, materiality, manufacturing and construction processes. Design intervenes and interferes with these processes and only succeeds when all these elements have been properly balanced.
Our expertise and experience in designing dwellings on sites with long-established trees and heritage constraints have taught us that the most effective response is a building which subtly blends into the environment, gives an impression of floating within the trees and harmoniously sits into its setting. The foundations of a building of this nature are probably the most important part of it.
The building essentially has roots itself as it sits on screw piles which can be inserted in appropriate locations to avoid any impact on the tree roots. It is almost an exercise of acupuncture to the ground, whilst also preserving its topography and existing levels. The pile foundations are ’planted’ only where needed and possible, without disturbing any other existing ‘foundations’ of the tree. This type of foundation does not involve any heavy machinery or methods which could be detrimental to the site, it is, therefore, a smoother technique to implant the building in the middle of the maze of tree roots.
Blending the architecture within nature can also be successfully achieved with the appropriate choice of materials; those which age and weather with the ecosystem they have been implanted into, until the built element looks like it has always been there. The building becomes an organic element quietly sitting like a chameleon into the site and the tree canopies, while vegetation takes over the architecture and embraces it.
It is important to ensure that sufficient levels of natural light can enter the internal spaces of the house, the right orientation of the building and the adequate provision of openings in the right place are key. This is whilst bearing in mind that openings such as roof lights would require regular maintenance as there will inevitably be tree leaves and natural detritus stacking up onto them through time and seasons. These can be avoided and alternative high-level openings such as clerestories, and light scoops can be integrated into the design. The beauty of living in a tree house is enhanced by the blurring of the boundaries between internal and external spaces.
Fragmenting the building and breaking it down into parts can sometimes contribute to a better adaptation of the architecture to the site. This is then followed by an exercise which consists of framing the views and openings, as well as the way they look out onto the trees and the rest of the site. This ‘adapt and blend’ approach to the design results in a building generated by the site, the trees and the ground. It is as crucial to ensure that the building does not have a negative impact on the site as it is to avoid obscuring the views from the neighbouring properties and surrounding key locations, especially on curtilage listed sites and conservation areas. Therefore, designing within reasonable heights and providing an acceptable building footprint in proportion to the site is an important part of the proposal.
All along the design process of a tree house, from start to completion, ecology and biodiversity should stay at the heart of the architectural response. The presence of various tree species, protected animal species and specific characteristics relating to the ecology of the site should be carefully accommodated as part of the design. After all, they were there first, and the future users will be moving into their habitat. Therefore, as part of our tree house schemes, we aim to enhance the existing biodiversity and rewild the site all around the building by providing additional planting of local species and adequate interventions to provide appropriate habitat for animals and insects. This not only enhances the biodiversity of this new little ecosystem but also ensures a more immersive experience into nature for the building’s occupiers. It also helps screening the architecture, subtly blending it and accelerating its integration into the environment.
To immerse the building further into the vegetation and tree canopies, green bio-diverse roofs are often an effective way to both enhance the biodiversity of the site and mimic an aspect of the trees.
Indeed, trees are complex organisms which have a symbiotic relationship with other organisms that benefit each other such as lichens, fungi and algae which grow on the tree bark. Green roofs somehow imitate this natural phenomenon as microorganisms will eventually grow on the roof of the house. To take this even further, climbing planting onto the elevations of the building can help this integration process. Tree roots need water, and to allow rainwater to infiltrate the ground and the roots, we ensure that any walkways and platforms around the house are designed in a way that lets the water through to the ground, this can be in the form of meshed or perforated materials. The trees and their surrounding environment are interconnected and so becomes the house once a perfect balance has been achieved, following which the human factor is then added to the equation.
Just like trees and plants breathe, a building similarly does so. It is an integral part of the design process to get the building to perform energetically as well as possible, this includes high levels of insulation, good air-tightness, increasing solar gains in winter and decreasing solar gains in summer, having passive ventilation where possible, etc. Essentially, reducing the carbon footprint of the building makes it more compatible and deserving to sit within trees which contribute to reducing atmospheric carbon every day. Sustainability in architecture and construction is now an emergency rather than an option, therefore endeavouring to achieve good energy performance is vital. Among other alternatives to make this happen, manufacturing parts of the building off-site and using locally sourced materials is encouraged.
Unusual contexts pose unique challenges, and unique challenges generate exceptional designs. Tree houses make us go back to the essentials of our human nature and our childhood instincts, whilst making the best out of the contemporary innovative building techniques. The building evolves with the trees and its surroundings, continuously adapting and changing throughout the seasons. And at MHW, we love telling the unique stories of how a site and its trees can germinate an exceptional building.
Sara Carmen Ramadane
