Building A Sustainable Future

CONSTRUCTING A SUSTAINABLE FUTURE

INTRODUCTION

To keep up with Australia’s growing population, the demand for housing, commercial buildings, social spaces and infrastructure is increasing at a rapid rate. In June 2022, the total number of dwellings under construction reached a record high of 241,926.1 Experts predict even greater construction activity in the future, with the value of construction activities in Australia anticipated to reach over $213 AUD billion in the 2025 fiscal year.2

However, there is concern that this increasing pace of construction may cost us the Earth. According to the National Waste Report 2020, Australia generated 27 million tonnes of waste from the construction and demolition sector in 2018-19,3 a figure representing 44% of all waste in the country.4 Globally, construction is responsible for an estimated third of the world's overall waste, and at least 40% of the world’s carbon dioxide emissions.5

If we want to reduce the quantity of waste and emissions generated during the construction process, we need to take a closer look at the life cycle of the products we build with. Until now, we have typically designed, built, and operated structures using the linear method of production; raw materials are collected, then transformed into products that are used up then thrown away. In order to secure the sustainability of the industry and the environment, we must instead adopt the concepts of the circular economy—a solutions framework that aims to decouple economic activity from the consumption of finite resources.6

It is becoming clearer that a transition to a circular economy is necessary to avert environmental disaster and mitigate the impact of climate change. The building and construction industry is crucial to this shift. In this whitepaper, we examine the circular economy model, its significance, and the tactics that designers and architects may implement to benefit businesses, people and the environment.

LINEAR ECONOMY VS. CIRCULAR ECONOMY

Much of human production and consumption in general, including traditional building design and construction, follows a linear resource flow. A linear economy follows the "take-make-dispose" model; raw materials are gathered, then turned into useful goods, which are eventually thrown out as waste. This process consumes vast amounts of finite natural resources, while generating hazardous pollutants and waste that cannot be recycled by nature.7 Value is produced by making and selling as many items as possible.8

KEY CIRCULAR PRINCIPLES

Design out waste and pollution

Most of the waste we generate is disposed of in landfills or incinerators, never to be reused again. As the resources on our planet are limited, this system is unsustainable over the long run.9 Understanding that waste and pollution are largely a product of the way we build things and coming up with new and creative ways to design out those negative aspects is the first tenet of the circular economy.10

This principle often means companies need to radically rethink the way they design and manufacture products. Some examples include edible fruit and vegetable packaging that eliminates single-use shrink wrap, or textile dyeing technology that does not use water thus reducing the creation of toxic waste water.11

Keep products and materials in use

The circular economy encourages us to keep materials in use, either as finished products or components of other products, so that nothing becomes waste and the value of products and materials are maintained.12 Accordingly, the circular mode of production places emphasis on durability, reuse, remanufacturing, and recycling to keep products, components, and materials in circulation.

A circular economy is fundamentally different from a linear economy in that its key objective is to stop waste from being created in the first place. Underpinned by the transition to renewable technologies, it is a model of production that focuses on maximum sharing, leasing, reusing, repairing, refurbishing and recycling of materials, goods and components to decrease waste generation and emissions. In a circular economy, value is created by focusing on value preservation; whether the material can provide value even after the function is no longer needed.

According to the Ellen Macarthur Foundation, products and materials can be kept in circulation in a variety of ways, but two fundamental cycles generally apply: the technical cycle and the biological cycle.13 In the technical cycle, products are reused, repaired, remanufactured, and recycled while, in the biological cycle, biodegradable materials are returned to the earth through processes like composting and anaerobic digestion.14

In order to maintain the value of products and materials, they have to be designed to enable further use and circulation. Often this means designing products that are durable, easy to repair and easy to disassemble, and allow for biological and technical materials to be easily separated with the biological and technical cycles in mind.

Regenerate natural systems

The circular economy supports natural processes and gives nature more opportunity to flourish by shifting the focus from extraction to regeneration.15 There is a focus on providing feedback loops that mimic nature and actively improve our natural environment.

A notable example of this is the regenerative agriculture movement that includes practices such as enriching soils, improving watersheds and enhancing ecosystem services.16

Most of the waste we generate is disposed of in landfills or incinerators, never to be reused again. As the resources on our planet are limited, this system is unsustainable over the long run.

ASSESSING THE CIRCULARITY OF BUILDING MATERIALS

Applying the principles of the circular economy to individual building projects can be a difficult task. Circular economy maturity assessments are tools that allow stakeholders to understand the upstream and downstream impact of materials. By measuring the circularity of selected materials, we can determine the maturity of different product manufacturers in transitioning towards a circular economy.

When assessing the circularity of different products and materials, the distinction between biological and technical materials is important to keep in mind. Technical materials, such as metal and plastics, cannot be processed by biological systems but rather must be dismantled, reused or transformed after their initial use phase.17 Biological materials such as wood, cotton fibre and paper, on the other hand, are designed to be returned to the environment after initial use.18 Identifying where different materials sit in relation to these cycles will help when assessing and optimising for circularity.

After it is understood that the material is technical or biological, the emphasis must be on maintaining the material at its highest value for as long as possible. For technical materials, only once the technical cycle is exhausted should it be sent to recycling. In some cases, biological materials can be treated through the technical cycle to create higher value products. An example of this is creating engineered wood products out of timber, which is stronger and more stable that conventional timber and thus has higher potential for reuse.

When it comes to selecting safe and circular materials, it is important to know their chemical composition, where they come from, or how they are sourced. Selecting safe products that are created using recycled, reused, or properly-managed renewable resources is ideal.19 To promote circularity, technical materials can be derived from waste from another industrial process or created using post-consumer waste.20 With biological materials, the key question is whether they can be sourced in an ecologically responsible and renewable manner.21

CASE STUDY: CIRCULARITY ANALYSIS WEATHERTEX CLADDING

In 2020, to assess the circularity of five chosen materials, Coreo Pty Ltd analysed each respective material’s upstream and downstream material journey from the Coomera Foreshore and North Lakes Vida project sites on behalf of Stockland, a diversified Australian property development company. This information would help Stockland identify challenges, opportunities, and actions towards creating a circular economy particularly in areas where the company has direct control and could create systemic impact in the supply chain.

Using the five chosen materials as a starting point, Coreo developed a Circular Economy Maturity Assessment (CEMA) to analyse, measure, and assess the circularity of those materials and assess the product manufacturers' level of maturity in moving towards a circular economy. The CEMA includes a quantitive assessment of input and output material flows and provides a score based on how circular a company’ products and materials are today. The qualitative assessment evaluates indicators in four thematic areas: strategy and planning; innovation; people and skills; and external engagement.

Weathertex cladding was included in the circularity analysis, achieving an outstanding quantitative circularity score of 86%.

Weathertex is an Australian owned and operated manufacturer of timber cladding, weatherboard and architectural panels. The following factors contributed to the company’s high circular score:

• Weathertex cladding is 97% hardwood timber, 3% paraffin wax and less than 1% acrylic primer, titanium dioxide, and tinted acrylic. No toxic or hazardous chemical additives are used. While the product is made of 97% virgin materials, the materials are renewable and sustainably sourced.

• The timber used in Weathertex’s products is from inferior trees considered a waste product and sourced from PEFC-certified suppliers and controlled sources.

• 97.5% of all waste materials generated from the production of Weathertex’s products are reused.

• While Weathertex uses approximately one million litres of water per day, 85% of it is recycled water from an onsite aquifer and recycled water from the facility.

• Weathertex products have a long life expectancy (50 years).

• The majority of Weathertex by-products (75%) are recovered at their end of life and turned into additives for compost.

This figure depicts the journey of Weathertex cladding from the Stockland design brief to their manufacture, use in the Medium Density Projects and journey downstream to either reuse or disposal in landfill. Figure 4. Weathertex cladding supply chain material journey

Source: Coreo Pty Ltd. Stockland Supply Chain Management: A Circularity Analysis (Stockland, 2020).

APPLYING CIRCULARITY TO BUILDING PROJECTS

The shift from a linear to a circular economy requires businesses to rethink how they interact with materials and building products. Circularity principles must be considered from the outset of any project. Where the client and project team are aligned, it is recommended to work with an assessor to record and assess the project within the circular economy framework.

Designers and specifiers have a critical role to play. Material selection is an important factor in designing for a circular economy. By choosing healthy, sustainable and circular materials, you can ensure that they can be

used and reused safely for the benefit of humans and the environment. The distinction between biological and technical materials is one factor that will determine whether building products can have a second life after their initial use.

A specific set of design strategies should also be used to provide reversibility, adaptation, and flexibility. This includes designing connections and intersections so that they can safely and easily be disassembled. From an economic and environmental perspective, allowing building elements and materials to be disassembled into components and then reassembled into new combinations is preferable than the cycle of demolishing and rebuilding structures.

A better choice, naturally

All Weathertex boards are manufactured using waste timber sourced from Australian, PEFC-certified harvesters and controlled sources. No old growth hardwood is ever used, so there’s minimal environmental impact and avoids depletion of natural resources. Weathertex timber product is the only product of its kind in the world containing absolutely no added silica, glues, resins or formaldehyde.

Weathertex is a family-owned Australian manufacturing cladding company, operating in NSW since 1939. No toxic or polluting chemicals are added to Weathertex products during the manufacturing process. The manufacturing process of all Weathertex products minimises waste by-products through resource recovery systems. This includes selling the wood dust and bottom ash used in the process to create compost, using the offcut board as fuel and using it as packaging.

Weathertex’s on-site bore water management system is unique and highly sustainable, it reduces water usage by ensuring processed water is treated and recycled. Like most timber products, Weathertex can be reused/repurposed for various usages – other construction applications, recycled into packaging, used as fuel or turned into compost. Even in landfill, Weathertex does not rot/breakdown, so the carbon stored in it will remain contained indefinitely.

Better than zero carbon footprint

Weathertex's factory creates less of a carbon footprint during the manufacturing process than the timber product can absorb and store, giving Weathertex its unique “better than zero carbon footprint.” In other words, Weathertex is able to reduce their carbon emissions and sequester carbon through the use of sustainable forestry practices, resulting in a net positive impact on the environment.

Circular economy maturity assessments are tools that allow projects to analyse the upstream and downstream impact of materials. By measuring the circularity of selected materials, we can determine the maturity of different product manufacturers in transitioning towards a circular economy.

REFERENCES

1 Australian Government. “Building Activity, Australia.” Australian Bureau of Statistics. https://www.abs.gov.au/statistics/industry/building-and-construction/building-activity-australia/latest-release (accessed 17 February 2023).

2 Statista. “Value of construction activity in Australia from financial year 2015 to 2020 with a forecast until 2025.” Statista. https://www.statista.com/statistics/1050009/australia-construction-activity-value (accessed 17 February 2023).

3 Pickin, Joe, Christine Wardle, Kyle O’Farrell, Piya Nyunt, Sally Donovan. “National Waste Report 2020.” Department of Agriculture, Water and the Environment. https://www.dcceew.gov.au (accessed 17 February 2023).

4 Ibid.

5 Miller, Norman. “The industry creating a third of the world's waste.” BBC. https://www.bbc.com/future/article/20211215-the-buildings-made-from-rubbish (accessed 17 February 2023).

6 Ellen Macarthur Foundation. “What is a circular economy?” EMF. https://ellenmacarthurfoundation.org/topics/circular-economy-introduction/overview (accessed 17 February 2023).

7 Ibid.

8 Het Groene Brein. “How is a circular economy different from a linear economy?” Het Groene Brein. https://kenniskaarten.hetgroenebrein.nl/en/knowledge-map-circular-economy/how-is-a-circular-economy-different-from-a-linear-economy (accessed 17 February 2023).

9 Ellen Macarthur Foundation. “Eliminate waste and pollution.” EMF. https://ellenmacarthurfoundation.org/eliminate-waste-and-pollution (accessed 17 February 2023).

10 Ibid.

11 Ibid.

12 Ellen Macarthur Foundation. “Circulate products and materials.” EMF. https://ellenmacarthurfoundation.org/circulate-products-and-materials (accessed 17 February 2023).

13 Ibid.

14 Ibid.

15 Ellen Macarthur Foundation. “Regenerate nature.” EMF. https://ellenmacarthurfoundation.org/regenerate-nature (accessed 17 February 2023).

16 Taylor Liam. “Three Core Principles of the Circular Economy.” Planet Ark. https://planetark.org/newsroom/news/three-core-principles-of-the-circular-economy (accessed 17 February 2023).

17 Ellen MacArthur Foundation and IDEO. “Material selection.” Circular Design Guide. https://www.circulardesignguide.com/post/material-selection (accessed 17 February 2023).

18 Ibid.

19 Ibid.

20 Ibid.

21 Ibid.

All information provided correct as of March 2023