construction – Things Are Good

Using Dirt From Tunnels to Build New Stuff

picture of a tunnelling machine

Digging a subway means cutting through a lot of dirt, but what to do with it? This is the question that has troubled many construction sites throughout the years and depending on where you’re digging dirt you have different options. The worst, but all too common, option is to send the dirt to a landfill as ridiculous as that sounds. When Line 2 was being built in Toronto they used the dirt to build a whole new park and that approach is becoming popular the world over. Now Toronto is building a new subway and the dirt is being used in nifty ways too.

The hallmark for all cities to get to is the standard set by Paris.

Some global jurisdictions have pushed further into circular approaches that go beyond simple reuse. In France, large volumes of soil from metro construction projects have been integrated into systems designed to keep material within the local economy. Regional operators manage large-scale soil redistribution for parks, green spaces, and land restoration, creating a coordinated soil logistics network across Paris.

Paris’s proactive initiatives like Cycle Terre, carried out between 2018 and 2021, processed suitable excavated clay from the Grand Paris Express project into compressed earth blocks and other low-carbon building materials from a factory 10 kilometres from the excavation sites. This resulted in relatively short transport times and effectively turned soil into a construction input rather than a disposal burden. Ultimately, however, the initiative failed to generate enough commercial contracts and went into liquidation.

Cutting Construction Carbon

Building buildings takes a lot of energy and once done the built structure continues to consume energy and have a carbon footprint. Many options exist to reduce the carbon impact of buildings from the point of construction all the way to deconstruction, but the industry still needs to adopt these measures. Things are getting better though as more people in the industry understand how to think about the carbon footprint of the construction industry.

Take Whole Life Carbon Perspective

By plotting the impact of a building over time, we observed the tensions between upfront impact strategies and long-term solutions. Our class first employed a “whole life carbon” approach to assess emissions associated with the construction and performance of a range of façade systems, discovering that the bulk of an enclosure system’s upfront emissions stem from window systems reliant on carbon-intensive framing materials, such as aluminum or polyvinyl chloride. Last fall, we scaled our investigations up to the whole building, finding that the actual operational data uniformly eclipsed modeled emissions, and that the balance between embodied and operational emissions varied significantly across the campus’s buildings.

Architects Need to Build Their Knowledge to Build a Sustainable Future

Current popular building practices lack a nuanced approach to sustainability due to years of it being culturally ok to put future generations into ecological debt. Thankfully, things are starting to change and architects want to build a sustainable future, and fast. Prior to mass industrialization buildings were constructed using locally sourced materials, making them more sustainable with a relatively small carbon footprint. As globalization increased the techniques of using local materials were forgotten and now architects are calling for everybody in their field to share best practices around locally sourced material and techniques.

Architects are at the forefront of our drive to lessen the impact humans have on the environment. While the agenda has stayed relatively constant since I was at school, the sustainability goalposts have moved â€“ and narrowed. A building designed as zero-carbon just half a decade ago would now be considered â€˜operationallyâ€™ zero-carbon at best, whereas â€˜whole-life carbonâ€™ calculations now consider the buildingâ€™s demolition and waste disposal. Our thinking, designs and architectural goals must evolve, but things are evolving at such a speed; how on earth are architects to keep up?

â€˜Renewable and sustainable technologies change very quickly, as does our understanding of sustainable outcomes, so it is important to try to keep on top of it,â€™ says Tate Harmer partner Jerry Tate. â€˜We need to communicate to each other in our industry, sharing best practice and our experiences to help get to the right answers.â€™

To Build a Green Future We Need Green Buildings

Buildings suck up a lot of energy and thus are massive contributors to our collective carbon footprint. After they are built ongoing operational costs are incurred, and the costs are greater on buildings which are inefficiently deigned and built. This has led a team in the states to call for a new approach towards how construction functions in the nation. A green approach to build green is the dream.

Of course, the best thing we can do is work to reduce our demand on new buildings and re-purpose existing infrastructure to be more efficient.

With public demand growing for scalable climate solutions from all levels of government, policymakers can work together to transition the United States from a patchwork of requirements to a set of dynamic, performance-based policies that enable rapid decarbonization throughout a buildingâ€™s lifecycle. Zero-carbon building codes for new construction address the emissions from buildings constructed each year, while emerging building performance standards and policies can address existing buildings.

Bamboo is Super!

Bamboo grows quickly and so to is the market for bamboo. The plant can be used for many different things from building to bicycles, but what’s so great about it today is that more construction sites are aware of how great bamboo is. Bamboo can be used to build stand-alone structures or be used as scaffolding at a construction site – either way bamboo also acts as a carbon sink.

The fast growing rugged grass has â€œunrivaled capacity to capture carbonâ€ the article claims.

The bamboo industry hails the cropâ€™s other environmental benefits. Because it shoots up quickly – as much as a meter (over 3 feet) in a day – it is highly renewable.

According to the Bamboo Clothing website, it thrives without fertilizers or pesticides, requires little water, grows on slopes too inhospitable for other crops, and has a 10 times higher yield per acre than cotton. Want more? It does not uproot soil (harvesting involves cutting it as itâ€™s a grass) and itâ€™s 100 percent biodegradable, the website notes.

The World Bamboo Organization says todayâ€™s bamboo market is $10 billion and could double in five years. China produces about 80 percent of the worldâ€™s supply, but other nations are turning to it as a cash crop.