Case Studies on Decarbonised Construction | One Click LCA

Stubbe’s Precast EPDs for low-carbon concrete | One Click LCA

Written by Aileen Carroll | Feb 07 2025

Pioneering sustainability in low-carbon concrete manufacturing

Under the guidance of QA Manager and Plant Engineer Steven Van Wyk, Stubbe’s Precast transitioned from using industry average EPDs to developing their own in-house EPDs using One Click LCA software. This strategic shift empowered the company to identify carbon reduction opportunities, improve material efficiency, and benchmark against industry standards.

Why embodied carbon reduction matters

According to the World Green Building Council (WGBC), buildings are currently responsible for 39% of global energy related carbon emissions. Embodied carbon — a result of manufacturing, transporting, and disposing of building materials — constitutes a significant portion of these emissions. As energy grids decarbonise, the relative impact of embodied carbon will continue to grow. 

Low-carbon concrete roadmap to transparency at Stubbe’s Precast

Stubbe’s Precast leveraged One Click LCA to develop a comprehensive set of seven third-party-verified environmental product declarations (EPDs), covering a range of precast products, including hollow-core slabs, structural and cladding walls, beams, columns, and insulated wall panels​. By transitioning from consultant-led EPD development to an in-house approach using One Click LCA, Stubbe’s Precast gained greater control over its data analysis, scenario modeling, and carbon reduction strategies. 

Stubbe's Precast successfully achieved a 14.6% reduction in carbon emissions per ton of precast concrete between 2021 and 2024, while maintaining emissions 6.7% below the Canadian industry average​.

The EPD software enabled them to assess the global warming potential (GWP) of different material choices and production processes, identifying key emission hotspots. As a result, they successfully achieved a 14.6% reduction in carbon emissions per ton of precast concrete between 2021 and 2024, while maintaining emissions 6.7% below the Canadian industry average​. Stubbe’s Precast also used One Click LCA to model potential further reductions — revealing that strategic supplier selection, process improvements, and alternative material choices could cut emissions by up to 45% for certain products​.

 

Stubbe’s Precast replaced traditional cement with Portland Limestone Cement (PLC), reducing emissions while maintaining structural performance.

  1. Supplementary cementitious materials (SCMs): Increased use of SCMs further reduced the carbon intensity of concrete.
  2. Waste heat recovery: The plant implemented a heat recovery system, capturing and reusing waste heat to cure concrete more efficiently, significantly reducing reliance on natural gas.

These advancements, combined with continuous R&D on alternative curing methods, position Stubbe’s Precast as a leader in sustainable manufacturing.

Whole-building LCA: Evaluating systemic impact

To understand the broader implications of its efforts, Stubbe’s Precast conducted a whole-building life cycle assessment (wbLCA) for an eight-story residential building constructed using their innovative FastTrack system.

Stubbe’s Precast FastTrack is an optimised precast concrete construction system designed to accelerate project timelines while improving material efficiency and sustainability. By leveraging total precast structures — including hollow-core slabs, structural walls, beams, and columns — FastTrack reduces on-site labor, minimises construction waste, and enhances installation speed. A key feature of the system is pre-installed windows within precast panels, allowing buildings to be enclosed immediately upon assembly, reducing temporary weather protection needs and lowering site energy consumption. This approach not only shortens construction schedules but also aligns with sustainable building practices by optimising material use and reducing embodied carbon. 

The whole-building life cycle assessment (wbLCA) was conducted on an eight-story, 132-unit residential building in Ontario, and compared the project’s embodied carbon against the most stringent tier of the Toronto Green Standard (TGS v4).

Key findings from the wbLCA:

  • The project achieved an embodied carbon intensity of 220 kg CO2e/m² — exceeding the Tier 3 benchmark of 250 kg CO2e/m² set by the TGS .
  • Precast materials accounted for 70% of the building's embodied carbon, with very low contributions from transportation (1%) due to the plant’s proximity to the site .

This performance demonstrates Stubbe’s Precast alignment with leading sustainability standards and the advantages of prefabrication in reducing emissions during construction.

Results and impacts

  • Carbon reductions: Stubbe’s Precast achieved a 14.6% reduction in carbon emissions per tonne of precast since 2021, remaining 6.7% below the Canadian Precast Concrete Institute's (CPCI) industry average .
  • Transparency: Detailed EPDs have provided architects and contractors with critical data to make informed, sustainable choices.
  • Scalability: The adoption of One Click LCA has made it easier for Stubbe’s Precast to model future scenarios and continuously refine its processes.

A blueprint for low-carbon concrete industry leadership

Stubbe’s Precast exemplifies how a mid-sized manufacturer can implement cutting-edge sustainability practices to exceed industry standards. By combining technological innovation, data transparency, and strategic collaboration, the company has not only reduced its carbon footprint but also provided a replicable framework for others in the sector.

Instead of relying on external consultants, Stubbe’s Precast was able to take full control of its EPD development and carbon reduction strategies, generate its own third-party-verified EPDs, analyse carbon hotspots, and model reduction scenarios. Bringing EPD development in-house revealed a clear path to cutting emissions by up to 45%​. One Click LCA enabled faster decision-making, greater transparency, and deeper insights into material and process impacts, helping Stubbe’s Precast exceed sustainability targets and meet stringent standards like the Toronto Green Standard Tier 3​.

Manufacturers looking to reduce carbon, streamline EPD creation, and stay ahead of regulations can achieve the same results. With One Click LCA, you can quantify emissions, compare suppliers, and optimise materials — without outsourcing control of your data.