The environmental impact of construction waste

By Ivan Chen

Construction is a resource-intensive industry that produces significant waste, making sustainable solutions essential. (Credit: rhythmuswege/Pixabay)

Building infrastructure is a fundamental part of how societies grow and function. From condos to transit projects and commercial towers, these developments shape cities and keep daily life moving. But behind the heavy machines is an often overlooked issue: construction waste. 

The construction industry is one of the largest consumers of raw materials and energy globally. Some estimates suggest that the industry is responsible for over 30 per cent of the extraction of natural resources and a quarter of all solid waste globally. 

In Canada, construction, renovation and demolition (CRD) waste contributes nearly four million tonnes, or about 12 per cent, to the country’s solid waste stream. CRD waste includes numerous materials, like wood, asphalt roofing, drywall, metals, plastics, concrete, bricks and glass. 

Some CRD waste may also include chemicals, such as paints, solvents and heavy metals, that can pose environmental risks. If improperly managed, these substances could leach into soil and groundwater, contaminating surrounding ecosystems. Additionally, when organic materials like wood break down in landfills, they can release methane, a greenhouse gas. 

Every demolition and rebuild cycle incurs a sizable climate cost, ranging from the greenhouse gases released during the production of building materials to the transportation and disposal of construction waste. And as Canada pushes to address its housing crisis, construction activity will ramp up in major cities like Toronto. The increased construction of new homes in the coming years is expected to result in higher material use, demolition activity and waste generation. This adds urgency to managing CRD waste sustainably.

Challenges to managing construction waste

A few challenges can arise when trying to sustainably manage construction waste.

One is the volume and complexity of the waste. Construction generates large volumes of diverse waste. Managing this capacity and variety may require specialized handling, which can be expensive and complex. 

Along with tight schedules, this makes it difficult to implement effective, sustainable waste management. Disposing of all materials in landfills, including those that may be recyclable, is often cheaper and simpler.

Navigating waste management rules, permits and disposal requirements can be complicated and inconsistent across jurisdictions. Meeting these standards can be time-consuming and costly.

Solutions

Only about 16 per cent of construction waste is currently diverted in Canada, though there’s potential to achieve a nearly 85 per cent diversion rate.

To address these challenges, regulations should be supportive and streamlined to help increase demand for circular products and services. Offering tax incentives or subsidies could reduce financial barriers to sustainable waste management. 

Industry members and advocacy groups should advocate for policy reform and collaborate with environmental organizations and other sector leaders to better integrate circular and sustainable practices.

When it comes to the infrastructure, buildings should be designed to be adaptable, reusable and easy to disassemble. Reclaimed materials — salvaged from previous construction or manufacturing projects, like old buildings or structures — should be incorporated in new projects. 

Existing infrastructure should be repurposed and upgraded instead of being demolished. If infrastructure is built with disassembly in mind, demolition can be replaced with planned deconstruction to recover materials. 

Similarly, improving the overall efficiency and durability of infrastructure will extend its lifespan. Toronto’s Green Standard pushes new private and city-owned developments to meet stricter energy and emissions requirements, with the overall goal of making them more eco-friendly and climate-resilient. While it doesn’t address all the challenges of construction waste, it represents a small but important step in the right direction.

Lastly, by establishing organized marketplaces and storage spaces for reclaimed materials, builders can have consistent and convenient access to construction materials that might otherwise end up in landfill — strengthening the circular economy within the industry.

Summary

Construction activity is expected to grow in the coming years. Tackling construction waste will require coordinated efforts from governments, industry stakeholders and communities. As the world grows, sustainable construction waste management will be essential for building a cleaner future.

Edited by Jess Blackwell