Architect Kirsty Maguire explains why reusing an existing building is always preferable to demolishing and rebuilding. However, when buildings are in terrible condition or need radical alterations to make them habitable we should be looking to reuse, recycle and reclaim as many materials as possible. Kirsty shows us that with intentional and sustainable design, you can create a new structure with a wealth of history.
Interview with Kirsty Maguire
Kirsty Maguire is an architect and Passivhaus designer who specialises in reclamation practices and sustainable building. Along with her team, Kirsty has been involved a wide range of projects that focus on finding ways to recycle the wealth of resources in existing buildings and reclamation centres, instead of buying new. In this chat, Kirsty explains the steps that are taken throughout a reclamation centred project and describes how preloved items can bring beauty and creativity to your home.
Reusing and reclaiming materials is an essential part of sustainability and the future of construction
A lot of the narratives around Passivhaus certification and sustainable construction have a focus on new builds. Whilst these projects are great, we can’t solely focus on sustainable new builds for the future of housing. Kirsty highlights that we currently have a wealth resources in already existing structures. We don’t have the ability to start from scratch on everything, so reclaiming, renovating, and reusing will be fundamental for a strong circular economy and in creating a sustainable future of housing.
“We've done everything from little cottage upgrades to working with the UNDP in Armenia doing big, tower block retrofits. And that's really, you know, that's what's going to change the world in a short time.”
What is the circular economy?
“Circular economy is looking at materials not only in the use that they are now but also beyond that use and into their next life.”
The Seed is a new building constructed just outside of Dundee on a woodland plot. It is a home for two families and acts as a small-scale cohousing project, with shared access to living areas. When the project was originally brought to Kirsty and her team, it was intended to be an EnerPHit project on an existing structure, but after reviewing the building health, the team realised that the structure was in a very poor condition with a lot of damp.
“We drew the things that we're going to have to be taken out in red and the drawings were almost entirely red! There was very little left.”
As a result, the goal shifted from reuse to recycle and the team formulated a plan to demolish the existing structure and reuse as much of the material as possible in the new building. Bricks were used in a range of different ways, creating gabions that formed the foundation of the structure, as aggregate on the site and also in the garden to provide structure for the biodiversity growing that the client is developing.
The client was passionate about sustainability and biodiversity being at the heart of the project, which can be seen in the construction methods, choices of materials and the overall design of the house.
Reusing materials might mean changing their use
Not all reclaimed materials will be able to be used in the exact same way as they were before, so there is an aspect of creativity needed for designers to work out how to use them in new projects.
You don’t need to demolish an existing structure to be able to reclaim materials
There are some great resources out there for sourcing reclaimed materials, whether that be from architectural salvage yards, stone yards, and even online sites such as eBay, Gumtree and Freecycle. A great example, local to Kirsty, is Dundee Scrap Antics, which is a creative recycling and social justice enterprise, that aims to give preloved items another life.
“They might have something that's been sitting in the back there for years and years or even decades, which is exactly what you need for your project. So there are a lot of places you can go.”
Finishes are the easiest way to reuse in a Passivhaus
Structural components can be a bit harder because there won’t be any manufactures data to prove the efficiency of the product, in particular insulation. But this matters most in Passivhaus structures as you need this data to get the certification. Therefore, using reclaimed materials for your internal finishes can be a great way to improve the sustainability and character of your home.
Our current building industry doesn’t consider the richness of reclaiming materials
The current system is designed to make you go straight to the merchant and buy any materials new, it is considered efficient in both time and cost. But it doesn’t take into consideration the benefits of using reclaimed materials on the environment and the unique quality of the finished product.
“It doesn't take into account the rich wealth of recycled materials that exists out there.”
Demolition companies are incentivised to separate waste and avoid putting everything into landfill
With the presence of substances like asbestos, demolition has moved past the time of a wrecking ball and a skip. Now, it is a much more measured process, but there are still important considerations to be made and does depend on where the reclaimed material is used afterwards. Often, demolition companies have the materials taken away to be used in other projects, but Kirsty highlights that whilst this is much better than them ending up in landfill, the most sustainable use is in reclaiming materials and reusing them on the same site. In the case of The Seed, the asbestos was professionally removed, and the majority of the timber and plaster was taken to be used on other sites, but pretty much all the rest was reused on site, whether that was in the building itself, landscaping or in garden structures.
Surroundings can be a big influence on the design
In the design of The Seed, the woodland area in which the site is situated, influenced a large amount of the design as well as the environmental performance. Internal layout can be designed to maximise the connection to the outdoor space and the use of two different colour clay plasters inside differentiates between the two families’ zones in a cohousing living space. As a result, you create a warm atmosphere both thermally and emotionally, that sits within the land not on it.
“As the client described it, almost womb like. Very enveloping and warm and cosy. Not only from a thermal performance point of view, but from a sort of emotional point of view.”
You must not only consider how the building will be constructed, but also it’s deconstruction in many years to come
The construction of The Seed focused on installing root protection and avoiding the use of concrete and cement when laying the groundwork. They decided to use steel screw piles for the foundation as they could position them in relation to the tree roots and can be removed with little impact at a later date. Kirsty also pointed out that even if the steel piles can’t be reused in a future project, they can be recycled.
“This comes back down to the thinking about the whole building life. So you in the same way that we were looking at the previous building that was on the site, that was at it’s end of life, and identifying the type of materials that we can reuse within that, despite the fact that when it was built that wasn’t what was being considered. What we're looking at with a new building is how that building could be taken apart at the end of its life… steel screw piles can be taken out with relatively small impact on the ground, and considering other materials as we go through as to what can be reused and recycled when it does come to that point”
… and it’s embodied carbon impact
Kirsty was yet to receive the data for the embodied carbon of steel screw piles, but did highlight that it is often the renewable energy devices that hold the highest embodied carbon of a project. You can influence this, depending on where you source you Solar PV, for example, can have a big impact on the level of embodied carbon. It is therefore much easier to control the embodied carbon of your above ground materials and it is often about looking at how to balance it all.
Remember to consider your waste management
Kirsty explains that in the construction of The Seed, they highlighted that root protection was an area of potential waste as it requires a large quantity of gravel. To get around this, they were able to use reclaimed materials from the demolition and any left-over material was used in another of their building sites.
Root protection has many benefits
Root protection is often a planning requirement for sites that have trees surrounding the foundation. The Seed was being constructed on a woodland site with many mature trees and root protection was required. The team found that not only did this process protect the trees, but it also protected the soil during construction and helped to avoid the perils of a muddy, winter, construction site!
“the contractor commented that they really loved having the reputation down because it meant that the site was very clean… you're not wading around in the wintertime, with mud up to your ankles, tracking it through the whole building site.”
Aim to continue the ethos through every stage of your build
It’s not only the shell that must be considered when creating a sustainable home. When you carry a mindset through every step of the process, right down to the internal finishes and furnishings, you achieve a cohesive design with much more intention. Kirsty talks about how Caroline (the client for The Seed) achieved the majority of her internal finishes with furniture she already owned, or second hand finds, rather than buying new and contributing to landfill waste. Each feature tells a story, in particular, the wooden platform made from materials reclaimed from the sailing club in Broughty Ferry that her site manager was involved in constructing all those years ago. This continuation of her overall ethos has created not only a beautiful design but a sense of history within a new structure.
“It's really interesting. So unexpectedly, these little stories start to come up and get created about the building too”
Remember to consider the biodiversity and ecology of your site
Kirsty also highlights that biodiversity and ecology are at the centre of their practice when renovating, demolishing, and reconstructing buildings. The presence of bats is a common occurrence in reclamation projects as these structures have been standing for a long time and it’s not only the previous owners that will have called them home. It is therefore important that the proper surveys are done, and any findings must be checked by a local ecologist.
“What's existing there already? It's not just the humans… who call the houses their home.”
Collaboration and a good team is key
Having a team that all share the same goal for a project is vital and if overlooked you may end up with a different end product than what you had envisioned. Storage in key when reclaiming materials as they will often be sat around for a while before they can be reused and in that time, they need to be stored within the right conditions. This requires an additional level of planning and coordination, so a good team that all understand the ethos of the build is crucial. Without this, things may become very difficult.
“It might be that the architect and the client find some amazing things together in terms of materials to reuse. But if you've working with the wrong contractor, then they're not going to be picking that up or vice versa… But when you get a great contractor to work with, or anybody else from the design team or the or the build team, then everyone putting their heads together to find solutions really can make the reused materials sing.”
Don’t be overwhelmed by the prospect of reusing and recycling in your build
Once you get into the process it can be really fun and exciting! Reclaiming and sourcing second hand materials can be a creative exercise in problem solving. You will likely end up with a range of unique and high-quality features in your home that will each tell their own story.
The industry has come a long way in the past 10 years
10 years ago, it would have been very difficult to find data on embodied carbon and embodied energy but today there is rich data base to help guide you. PHHP is a relatively quick modelling tool which also has a feature to check the embodied carbon and embodied energy of materials, allowing you to begin the process at a relatively low cost.
“if you're using PHPP… then you can choose whether you think that extra 50 millimetres of insulation is worth the cost or not and… that puts the control for specification and budget firmly in the design team and clients pocket, which is fantastic.”
Copyright – Grant Anderson / www.grantanderson.me / @grantandersondotme
Your project shouldn’t feel like a juggling act of different goals
Building projects should aim to have your goals working together cohesively rather than battling one another. This brings us back to our topic from last week; embodied carbon vs energy efficiency. Kirsty explains that we shouldn’t view them as competing goals, but instead as different factors that need to work together. You don’t need to forgo one to have the other, but you may need to spend a little longer working out how you can get them to work together harmoniously.
“thinking about the impact of the construction, in the same way that we've been able to look at the performance is a really powerful tool… For a long time, we were focusing on performance, and the decisions that you might make instinctively are often right, but they're not always. And it's exactly the same with embodied carbon and embodied energy.”
Ella Gardiner is a recent graduate from the University of Exeter with a BA in Politics. Her interest in sustainable living and ecological construction was ignited after being involved in her parents' Passivhaus self build.
If you want to build a house then the first thing you need to do is find land. Suitable parcels might be few and far between. And when you do find one, you could face fierce competition. Not only from other self builders, but also developers with deep pockets and bags of knowhow. Our free course will lead you through how you find your dream plot.
So your heart is set on building an eco home but you don’t know where to start. Well, that’s why we’ve developed a 10-part e-course to help you understand some of the important decisions you are going to have to make. Can you have a comfortable, healthy home with low running costs . . . that’s also good for the planet?