A REUSE MARKETPLACE
CASE STUDY:
REPURPOSING AAC BLOCKS

Background: In this project, a set of large AAC (Autoclaved Aerated Concrete) blocks, originally used in an art installation in various downtown Toronto neighbourhoods, were left abandoned with no use. What could be done with the leftover AAC blocks?

Challenge: Autoclaved Aerated Concrete (AAC) blocks, known for their functionality and insulating properties, are often used in construction. Starting back in July 2024, previous attempts were made by various teams to repurpose these blocks, but all efforts proved unsuccessful. The blocks were viewed as a challenge due to their size and weight – 7,200 blocks at a weight of 129,606 lbs. –  which made storing and moving them difficult. The owner had to find a practical and sustainable solution to repurpose abandoned blocks. 

Solution: The REUSE Marketplace. After assessing several possibilities, our team found a local farm in need of material to protect crops and trees from wildlife and weather damage. The AAC blocks, being both sturdy and easily adaptable, were perfect for constructing a strong, cost-effective wall. The REUSE Marketplace facilitated the customer connection, as well as the logistics of transporting the materials from the original site to the farm. 

Results:

• Environmental Impact: The AAC blocks were successfully diverted from the landfill and given a second purpose. In terms of overall embodied carbon:
  • Avoided manufacturing emissions: -1,340 tCO2e
  • Transportation to the reuse site: 4.6 tCO2e
  • Avoided landfill impacts: -429.8 tCO2e
  • Total carbon emissions saved: 1,765.2 tCO2e – equivalent to taking 541 cars off the road for a whole year. This is based on the average car driving 18,500 km annually.
  • Source: EPD for AAC blocks – global
• Cost Savings: Our efforts saved the organization over $7,000 in landfill costs, as well as multiple roll-off bin loads to the landfill.  Additionally, the farm customer saved money on traditional building materials, using high-quality, durable AAC blocks. 

• Community Impact: This project is an excellent example of how finding innovative ways to repurpose materials can benefit both the environment and local businesses. 

We’ve been running Canada’s longest-operating Zero Landfill Clean Material Recovery Facility. Projects like this highlight the crucial role our REUSE Marketplace plays in combating the climate crisis—offering low-cost, low-carbon solutions.