STEP BY STEP: Saving the planet one cup at a time
Step by Step is the blog of Kate Kerin Interiors. In addition to following some of my clients’ projects, I examine some of the latest issues of interest in the world of interior design.
Sustainable concrete
In my last post, I noted that increasingly clients are becoming aware of, and interested in, the ways their renovations can be sustainable. Joanna’s bathroom in Petersham was a case in point; every decision we made was seen through the lens of sustainability - was this the BEST choice that we could make, within the available budget? It was eye-opening for me, and I think in the end we did a pretty good job.
Recently I read a fascinating article about Australian research which just might change the face of construction (and thereby renovation and interior design). Engineers from RMIT were seeking a solution for recycling organic waste, which usually ends up in landfill and accounts for around 3% of greenhouse gas emissions in Australia. As dedicated coffee drinkers, Aussies apparently generate 75 million kilograms of coffee ground waste each year! This group of clever engineers worked out how to turn coffee grounds into biochar, a product that is similar in particle size and structure to sand. They did this without oxygen, at extremely high temperatures using a low-energy process, creating a product that can be used in cement as a substitute for sand - and not only that, the concrete that used biochar was found to be 30% stronger than that using sand!
Why does this matter, you may ask? Concrete, one of the strongest and most important substances used in creating buildings, is made of sand and cement mixed with water. Builders and home renovators use concrete all the time - it’s strong, it looks terrific and it lasts. But producing concrete is not a very environmentally friendly activity - it accounts for between 4% and 8% of the world’s carbon dioxide (fourth only to coal, oil and gas) and the process emits air pollution. The sand used in concrete is a non-renewable resource that must be mined and the creation of cement accounts for 10% of the world’s water usage.
Now although this research doesn’t solve the issues of water usage and any environmental damage done by the cement, there are a number of sustainability advantages to using this product. First, the biochar replaces sand as an aggregate, potentially saving up to 50 billion tonnes of sand per year (not all used for concrete, but still….!), reducing dredging and erosion as well as limiting the use of a finite resource. In addition, it proposes a circular-economy model of re-using products in a completely different way, reducing waste. It potentially removes millions of tonnes of coffee waste from landfill, where it would release greenhouse gases such as methane into the environment before eventually breaking down.
Although it’s early days for this research, the construction, architecture and interior design industries can (and in my opinion, should) get behind the plan and support ways to make concrete more sustainable.
Full disclosure - I am not an expert in any of this (so please forgive any errors in the information presented here!) But as a humble interior designer based on Sydney’s north shore, I find it fascinating to hear people who ARE experts in this field talk about their amazing ideas and positive, problem-solving initiatives. They are truly looking for ways we can replace old technologies with new ones that put the planet first. Hats off to RMIT researchers Dr Rajeev Roychand, Dr Shannon Kilmartin-Lynch, Dr Mohammad Saberian, Professor Jie Li, Professor Guomin (Kevin) Zhang and Professor Chun-Qing Li. For more information on this groundbreaking idea, go to RMIT’s website.
KK Interiors specialises in working with residential clients in Sydney, particularly older people who are downsizing or live independently in lifestyle resorts. Contact Kate for an initial consultation to talk about your project.
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