This knowledge base article provides an explanation of how we arrived at the values used in the Carbon Cost calculation.
Introduction:
In late 2022, Envirocon took a significant step by registering New Zealand's first precast concrete Environmental Product Declaration (EPD). This EPD serves as a comprehensive guide detailing the environmental inputs and footprint of our products. EPDs are independently produced, verified, and registered documents that provide valuable insights into a product's environmental impact. Envirocon's EPD showcases an exceptionally low embodied carbon footprint, with potential reductions of up to 97% compared to standard precast products.
To further emphasise our commitment to environmental sustainability, Envirocon has introduced the concept of "Carbon Cost," which allows us to illustrate the relative carbon footprint of our products compared to other common solutions.
Carbon Cost Calculator Overview:
The Carbon Cost calculator is designed to provide a relative indication of the carbon footprint of Envirocon products in comparison to other prevalent building materials. It is essential to note that this tool is intended for demonstration purposes and may not provide 100% accuracy, as a comprehensive analysis would require evaluating the structural design of all building materials, which is not practical.
Calculation Process:
The Carbon Cost calculator operates based on the following key components:
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Baseline Information: The initial data input includes the quantity of blocks specified for a structure. This quantity is then converted into indicative wall square meterage and tonnage.
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Comparative Analysis: The tonnage and square meterage of the wall are used to compare Envirocon products against five common building materials.
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Baseline Embodied Carbon Calculation: Envirocon blocks are assigned a baseline embodied carbon value of 6.7 kgCO2e per tonne.
Comparative Values:
Here are the baseline embodied carbon values used for the comparison of Envirocon products with other building materials:
- Envirocon Blocks: 6.7 kgCO2e per tonne
- Precast Panels: 202 kgCO2e per tonne
- Shipping Containers: 1500 kgCO2e per tonne
- Precast Segmental Wall: 202 kgCO2e per tonne
- Gabion Baskets: 13.66 kgCO2e per tonne
- Timber: 34 kgCO2e per tonne
Explanation of Comparative Values:
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Envirocon Blocks: This value is derived from the registered EPD for Interbloc, with an embodied carbon profile of 15.7 kg CO2 e/M3 of concrete converted to tonnage at 2340 kg of concrete per m3.
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Precast Panels: As there are no registered EPDs for traditional precast products in New Zealand, Australian precast product EPDs have been used to estimate embodied carbon. The lowest reported value of 202 kg per tonne is included for a conservative comparison.
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Shipping Containers: An average embodied carbon calculation of 1500 kg of CO2e per tonne of steel manufactured is used, based on data reported by the International Energy Association. This is provided for comparative purposes but may not precisely reflect the actual embodied carbon in steel containers.
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Gabion Baskets: An EPD for gabion baskets registered in Europe is cited, with a declared footprint of 0.906 kgCO2e per kg of the box. An average weight of 20 kg per gabion is considered for the calculation.
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Timber: Multiple EPDs registered for timber produced in New Zealand indicate an average GWP of 34 kgCO2e/m3 of softwood timber on a GWP-fossil basis. The calculator assumes a timber density of 490 kg/m3 and specific dimensions for the comparison.
Calculator Disclaimer:
Every calculator carries the following additional disclaimer.
Carbon intensity is GWP expressed in kg CO2 equivalent per tonne. Equivalencies sources from the US Environmental Equivalencies Calculator available here, numbers based on the highest potential saving. The information included on this page is primarily designed to be demonstrative of relative carbon intensity, and therefore carbon reduction opportunities between common building materials. The information is be generic by nature, and so many not accurately reflect every consideration on your project.
General Note:
It's important to understand that the values used in the Carbon Cost calculator are intended for illustrative purposes. Envirocon acknowledges that the values associated with non-Interbloc products may not precisely reflect their embodied carbon profiles due to the absence of registered Environmental Product Declarations covering those products in New Zealand. The provided values are conservative estimates aimed at erring on the side of caution while showcasing potential CO2e savings.
Conclusion:
Envirocon's Carbon Cost calculator offers a valuable tool for assessing the relative carbon intensity and potential carbon reduction opportunities between common building materials. While it may not provide absolute accuracy, it serves as a powerful tool to demonstrate Envirocon's commitment to sustainability and environmental responsibility.