The question of how to create a sustainable project is always at the forefront of our thinking. Central to our approach is a belief that the most sustainable type of project is one that can endure for many years without the need for redevelopment or demolition. Given that on residential projects, over half of the building’s whole-life carbon is emitted during its construction (RICS), making projects that are a specific response to client / user / community requirements is at the core of our approach. We invest time into discussing and developing the brief with our clients/ users / community - understanding how they live and scenario testing how they might live in the future. This allows us to create responses that are unique to them, ensuring the project can suit and adapt to their needs.
More of our clients are becoming aware of low-carbon materials such as hempcrete, cork etc. These innovative construction materials are 'better-than-zero-carbon materials' whilst also reducing the heat losses of the building. Although less conventional now, it seems like the construction industry is headed in the direction of materials such as Hempcrete. We are also keen to use more recyclable materials, such as polycarbonate, to reduce the wastage from the construction industry.
At our Cork House project we proposed cork for the new extension cladding - a material that had a pattern and texture which would compliment the existing London Stock brickwork. It is a sustainable material, naturally water resistant, recyclable and will weather to a silver-grey colour over time. It has inherent insulating properties which meant we did not require any additional insulation on the external walls. Cork not only ticks all the boxes when it comes to thermal and acoustic performance but is also breathable, free from chemicals, synthetic resins and carcinogenic materials and creates a healthy environment inside the house.
We are seeing more acceptance of these unconventional materials from our residential clients, the local authorities and developers.
When using natural materials it is important to make sure these can also satisfy regulatory and practical requirements, so it’s important to have a good team who can steer you through these challenges including a good Building Control Officer. The input of an architect can be particularly useful at the initial stages so that the overall design concept and aesthetics along with construction build ups can be considered alongside planning/ regulatory/ practical constraints.
On projects with a limited budget our focus is on where we can achieve the most impact for the least cost/ intervention. Cork and hempcrete are great because of their insulative properties but also the fact that they can both be composted down. The question of how to dispose of expanded foam and other similar crude-oil derived insulations hasn’t really been properly addressed. So using a material that can achieve the required thermal performance and that we know is easily and safely disposed of is reassuring for us and our clients. They are both natural materials which can be exposed internally and externally and we feel compliments existing brickwork, providing a consistent un-broken, textured finish.
Nimi Attanayake, NimTim Architects