Building a sustainable future: repair over replacement in Australian construction

This National Recycling Week, Building Chemical Supplies (BCS) underscores a pivotal yet often overlooked aspect of sustainability in the construction sector: the repair of concrete structures rather than their replacement. While Australia’s construction and demolition (C&D) industry has made commendable strides in recycling concrete waste, BCS advocates for a paradigm shift towards repairing and restoring concrete as a first step in sustainable construction practice.

Concrete repair presents a critical opportunity to extend the lifespan of existing structures before they reach recycling facilities, thereby conserving valuable resources and reducing environmental impact. According to BCS, the industry currently generates around 26.8 million tonnes of construction and demolition waste annually. Repairing concrete can potentially keep this material in active use for significantly longer periods, mitigating the demand for virgin raw materials, curbing energy consumption, and lowering carbon emissions associated with cement production, a process known for its high carbon intensity.

Queensland serves as a leading example within Australia’s waste diversion efforts. The State of the Environment Report 2024 highlights that 83.3% of Queensland’s C&D waste was successfully diverted from landfill in 2023–24, surpassing its 2025 recovery target of 75%. Around 1.6 million tonnes of concrete were recycled in this same period, reflecting substantial progress in waste management practices across the sector. Nonetheless, BCS points out that recycling processes come into play only at the end of a structure’s useful life. Prioritising repair techniques such as crack injection, spalling restoration, waterproofing, and carbon-fibre strengthening can safely extend the functional life of concrete elements by a decade or more, thereby reducing waste creation upstream.

National data reinforces the scale and impact of the challenge. The Australian Government’s National Waste and Resource Recovery Report 2024 reveals that construction and demolition waste accounted for 29.2 million tonnes in the 2022–23 financial year, approximately 39% of the country’s total waste generation. Despite an industry recycling rate of 84% for building and demolition materials, equating to 22.4 million tonnes recovered, there remains a pressing need to adopt circular economy principles more comprehensively.

Embodied carbon in buildings, which contributes roughly 10% of Australia’s overall greenhouse gas emissions, is a critical factor in the sustainability equation. Repairing concrete structures directly reduces embodied carbon by lowering the demand for new cement, whose manufacture is energy-intensive and emits significant CO2. This makes repair not only an environmental imperative but also a cost- and time-efficient solution for builders, engineers, and asset managers aiming to maintain infrastructure resilience while advancing carbon reduction targets.

Complementing repair initiatives, industry reports such as ‘Australia’s Waste[d] Opportunity 2025’ emphasise waste minimisation throughout the construction value chain, noting that the average building project discards 141 kilograms of material per square metre, with concrete, masonry, and tiles comprising the largest volumes. This reinforces the potential impact of repair and reuse strategies in preventing waste before it arises.

Blair Edmonds, Director at Building Chemical Supplies, summarised the company’s position during National Recycling Week: “Recycling is valuable, but before concrete becomes waste, there’s an opportunity to repair and reuse what already exists. That’s the real foundation of sustainable construction.” He urges the industry to focus efforts on extending the life of built assets, thereby easing pressure on recycling facilities, reducing material demand, and fostering a genuinely circular built environment.

In conclusion, while current recycling efforts signify important progress, sustainability in construction demands a proactive approach centred on repair and preservation. This shift promises to deliver substantial environmental benefits by conserving resources, reducing emissions, curbing landfill input, and driving down embodied carbon footprints. For Australia’s industrial decarbonisation goals and circular economy ambitions, repairing concrete structures is emerging as a vital strategy, one that complements recycling and drives the industry towards a truly sustainable future.