An architect explains why we should rethink how we build homes
In 2018, the United States generated 600 million tons of construction and demolition (C&D) debris, more than twice the amount of municipal solid waste generated in the same year.
That's a sobering figure, especially given the fact that roughly 145 million tons of that debris were disposed of in landfills. To make matters worse, global construction waste is expected to reach 2.2 billion tons by 2025.
Needless to say, the building industry urgently needs to address its end-of-life material management, and the smartest way to do so may be to guarantee that structures are built in a way that material recovery is easy and straightforward.
Imagine this: A future in which housing is so versatile that your kids could, for example, "unclip" their bedroom from the house and take it with them when they move out. This future could also see a house built in a couple of days, with construction waste quickly and effectively becoming obsolete.
Ged Finch, a Ph.D. candidate in the School of Architecture at New Zealand's Victoria University of Wellington, is on a mission to bring that future closer with his game-changing design, "X-Frame".
X-Frame is a self-braced interlocking system made of wood that clips together to eliminate the need for single-use fixings. With the goal of creating a building in which all sections can be easily disassembled and reused, X-Frame has the potential to eliminate waste and minimize the number of raw materials required by the construction industry.
Interesting Engineering recently had the chance to talk with Ged about how X-Frame might transform our future, the challenges of achieving a circular economy, and what the construction industry will look like in 2027.
The following conversation has been lightly edited for clarity and flow.
Interesting Engineering: In simplest terms, what is a circular economy model?
Ged Finch: The ambition behind a circular economy is to eliminate end-of-life waste and allow materials, products, and buildings to be recovered and reused rather than being thrown out.
IE: How are terms like net-zero and circular economy relevant to the building industry?
There’s a couple of aspects to this. One of them is that the construction industry is a major producer of carbon dioxide and a major consumer of energy. That's because creating the buildings that we live and work in require a lot of energy. Energy is also wound up in the production of materials, with cement being one of the largest single producers of CO2 — about eight or nine percent of all CO2 comes from cement production.
The impact that has on a net-zero target is that we produce a lot of emissions to create these buildings, which may only have a 50 or 75-year lifespan. Then, all of those materials must be processed or replaced, which is why there is a continual need to cut emissions in this sector.
IE: What's the idea behind X-Frame?
X-Frame is a response to the need to create a way of building that better allows materials to be disassembled and then reused on another building site. The principle that we have behind it is that everything needs to be able to be taken out of the building without being damaged, and we need to achieve as much utilization or as much value of that material as possible.
X-Frame does this by taking standardized building elements and separates the layers of a building into interchangeable layers that can be easily prefabricated, moved, standardized, and reused in other buildings.
IE: Can you explain the benefits and challenges of this idea?
One of our key focuses was how to design a structural system that allows all the layers of the building to be deconstructed. One challenge is dealing with how to effectively standardize parts so that [they] can be easily used across many buildings, as well as how to make these parts robust across those use cycles. So, while we want these things to last as long as possible, we don't want to utilize materials that use a lot of carbon.
We’ve spent a lot of time finding an appropriate material. We use engineered wood products to do that since they are more durable. Timber also has the appropriate negative carbon impact on the environment and doesn’t produce a whole lot of carbon.
Another part of that is dealing with reused elements, as there's a big perception in many sectors, particularly in the fit-out of commercial buildings, that reusing materials is unattractive. So, we had to create a system of parts that can be reused without looking recycled, secondhand, or recovered. The notion of a reuse economy not being attractive to people — it's been one of the biggest challenges.
IE: But can we achieve net-zero by cutting down trees?
Taking any material from nature has a negative impact. That's just the way it works, and some materials have smaller impacts than others.
For X-Frame, we use a product called Pinus Radiata. It’s a fast growing softwood timber. A Pinus Radiata can grow from a sapling to a fully grown tree ready for harvest in approximately 25 years. That means we can actually track how long it would take to replenish the material that we've taken from the forest.
We also have a very clear view of where the materials come from, how they were grown on which land, what impact they had, and the procedure that it takes to turn them into engineered wood.
Timber is a very interesting material because it's renewable, but this doesn't mean that steel, and other similar materials, don't have a place in a circular economy. We chose timber precisely because it works exceptionally well in this case.
If you're designing high-rise buildings, for example, using steel makes a lot of sense from a circular economy standpoint, because you'd get large reusable components that could be reused in future high-rise buildings. There's definitely some complexity around how you implement the circular economy across different scales.
IE: You’ve said the next generations may simply unclip their bedroom from the house and take it with them when they leave home one day. How would that work?
What we are moving towards as a company is beginning to lease building components to people. For example, when the children grow up, the parents could sell their room back to the company, or it could be relocated and reused elsewhere. Alternatively, the children can take the room with them to university or wherever they desire to reside.
There’s a lot of pressure on housing and infrastructure since there never seems to be enough houses in the right places. This idea of creating an infrastructure that can change with the population could give more freedom to people.
If we can actually begin to create an infrastructure that can move with the people, we can truly begin to revolutionize how we as various communities will and can live. It’s quite exciting.
This is a huge challenge, logistically and technically. And it's possible that we'll never see it in some places since the current building stock will never allow it. But there's no reason why new towns and structures can't be planned to be much more flexible and transient.
IE: What will the construction industry look like in 2027?
In the scheme of construction, five years isn’t long. It takes a long time to change things in the building industry. But I think that the move toward timber is going to get even larger and faster. And the only thing that could slow that down is not enough sustainably sourced timber.
I also think we will see a significant increase in recycled steel construction. This will be driven by increases in automation and massively customized manufacturing capabilities, such as robotic production for buildings and automation of that design to make pipelines. This will change the delivery speed and quality of buildings.
One of the things that might prevent us from doing some of this is the cost and the end of the abundance of the correct materials, [those] which are significantly better for the world in comparison to others.
So, in the next five years, there may be a lot of material innovation to try to cope with some of these material shortages, such as the use of recycled concrete aggregates, recycled concrete elements, low carbon concrete, and even 3D printing concrete to use some of these recycled materials.
There are challenges in all of this, because buildings are not just the structure, but they are all the other layers that make that up.
IE: You’ve said roughly half of all New Zealand’s waste is generated by the construction sector. Do you think that can change in five years?
No. This is one of the fascinating challenges that we have in front of us. In New Zealand, Australia, America, and Canada, many of the buildings aren't very old since these countries were only settled around 200 to 300 years ago. In fact, many of these buildings are almost built to be disposable.
As a result, they are going to be causing waste for the next 50 to 100 years, which means waste will likely increase before decreasing. That's really scary since we know we're not addressing the problem properly. Finding uses for such waste materials is an important part of trying to get to net-zero but also to a circular economy.
IE: When do you think the construction industry can achieve carbon and resource neutrality? How can it do that?
I believe there's a genuine chance that, with the right policies from the industry and government, we can take major steps in the next 10 years that will prevent the buildings we make now from generating waste in the long run. Then it'll be on all of us to make sure that whatever was built before is well managed towards the end of their lives.
IE: There are many who are reluctant to move toward green construction due to the higher cost during the building process. Do you think that’s going to change?
The circular economy is the only true way to address the issue of cost and construction since circularity makes secondhand, thirdhand, and fourth-hand recycled resources available.
As a result, the market is flooded with all of these other materials, meaning there is less need for raw new materials and prices can fall because they are not subject to the same constraints or demand. This way we don't have to seek for difficult-to-get items or go to great distances to obtain them.
It's true that there are upfront costs today; however, in the next five years, we may witness rising disposal costs, which will encourage the use of recyclable and reusable technologies, and then begin to reduce the cost of the raw product itself.
IE: Tell me about your perfect 2027. How would you like to envision the construction industry in 2027?
I'd like to see an industry-wide effort to standardize some fundamental parts of what we do. I don't think this would be too ambitious. We could make collective decisions about the materials we use, as well as their sizes and dimensions, heights, and links, that would allow us to transition to a circular economy much more quickly.
IE: What’s your next big idea?
There are numerous other reusable technologies that can be wrapped around X-Frame. For example, we are looking at reusable modular cladding systems and internal lighting systems, as well as the utilization of waste in products and a slew of other materials to help fuel a circular economy.
There's lots of other stuff coming, all with the aim of making construction as sustainable as possible.
IE: What advice would you have for young people looking to have a career in the construction industry?
I believe that the change that's happening in the construction industry, both in terms of advancing technologies and the push toward sustainability, makes it one of the sectors where you'll be able to have a significant impact on people's lives and see and feel that impact. That's even more reason to be involved, study in universities, and get your hands on materials, products, and new technologies as soon as possible. They could really change people's lives fundamentally.
Editor’s Note: This is a part of our special INTERESTING ENGINEERS ISSUE, where IE explores the greatest minds using ideas on the small scale to reshape the world on the big scale.