Welcome to the BC Low-Carbon Material Sourcing Guide. This guide is updated regularly with the latest materials which meet low carbon criteria.
Last updated Jul 31, 2023
Why This Guide?
The construction of buildings in BC is responsible for 7.5Mt of carbon emissions every year, that’s about 10% of all emissions produced within BC. These emissions are associated with the materials within a building and are known as the embodied carbon (or embodied emissions) of a building.
In order to meet our climate goals, the whole construction industry needs to dramatically change the way we design buildings, and to transition to low embodied carbon design quickly. The City of Vancouver has laid out it’s climate action road map, aiming to reduce all emissions by 40% by 2030 and to get to carbon negative by 2050.
There are many ways that designers and builders can reduce the embodied carbon of the buildings they are building, and many of these tools are available today, and at little or no additional cost:
Although material EPD databases exist, it is not directly clear which of those materials are available within BC, or even within Canada. And for those products that are available, builders and contractors are often unclear on where to source them. This guide aims to serve designers by providing a list of materials that are readily available within BC, and also provide builders and contractors with direct links to suppliers of these materials.
About This Guide
The global warming potential listed within this guide are reported directly from the EC3 database [link], which is a publicly available, free-to-use tool developed and maintained by Building Transparency. All materials within this guide have a verified EPD within the EC3 database. EC3 is one of the most expansive, publicly accessible EPD databases. Manufactures can submit their EPDs directly to EC3, and have the opportunity to report the country of origin as well as locations that the product is available to purchase. Very few manufacturers currently report on product availability, as such
All materials listed in the tables below are available for purchase within BC. In this first iteration of the guide, two material categories were identified as having the biggest impact on the overall embodied carbon of a building [1]. These are:
- Insulation (typically ~20% embodied carbon of a home)
- Concrete (typically ~35% embodied carbon of a home)
Note: Typical values listed here are as found in the City of Nelson Material Carbon Emissions Guide and consider A1-A3 (cradle to gate) only. Only materials with a verified EPD are included in this guide except for those included in the novel materials table.
Quick Links
Insulation
Insulation is unique in that there is a wide variety of insulation products on the market, designed to accommodate different applications (underground, wall, roof) and a variety of product formats (board, blown, batt, etc). It is not helpful to suggest only the lowest carbon insulation products, knowing that blown insulation is not a suitable alternative for projects that have been designed to accommodate board insulation. Unlike other materials, where increasing material efficiency, and reducing material volumes is a key strategy to reduce overall embodied carbon, using less insulation will often result in an increase in operational emissions. Consequently, choice of insulation has a significant impact on total carbon.
Blown Insulation
GWP [kgCO2e/m2 @RSI1] | Manufacturer | Product | Location | Supplier | EPD |
---|---|---|---|---|---|
0.1344 | ROCKWOOL International A/S (Rockwool North America) | Rockwool Stone Wool Thermal Insulation for Buildings | Province Wide | View Supplier | View EPD |
0.2971 | Knauf Insulation | EcoBatt® batts and rolls Unfaced, Kraft, FSK, Foil EcoBatt | Province Wide | View Supplier | View EPD |
0.4702 | Celotex Saint-Gobain | Acoustic Partition Roll (APR 1200) 75mm & 100mm | International - shipped | View Supplier | View EPD |
0.5768 | Owens Corning | EcoTouch PINK (R19, Unfaced) | US - shipped | View Supplier | View EPD |
Batt Insulation
GWP kgCO2e/m2 @RSI1 | Manufacturer | Product | Location | Supplier | EPD |
---|---|---|---|---|---|
0.2062 | Applegate-Greenfiber | SANCTUARY® by Greenfiber® Blow-In or Spray-Applied Insulation (Salt Lake City production facility) | Lower Mainland | View Supplier | View EPD |
Vancouver Island | View Supplier | ||||
1.099 | Owens Corning | Unbonded Loosefill - Atticat | Province Wide | View Supplier | View EPD |
1.099 | Owens Corning | Unbonded Loosefill - Propink L77 PINK Fiberglass | Province Wide | View Supplier | View EPD |
Varies by store, contact directly to confirm shipments between stores
Concrete
Unlike other materials, concrete is inherently local, and products vary widely by geography. Supplementary cementitious materials are often used to reduce the GWP of concrete, but availability of these is also dependent on location. The CRMCA recently published an industry average EPD for concrete produced in BC [4]. This allows designers to establish the realms of possibility for different mix requirements.
In addition to specifying “low-carbon” concrete, designers can minimize their carbon footprint by:
- Minimizing the volume of concrete, they use on a project. Use concrete only where necessary, and do not use concrete where the strength or durability properties of concrete are not required. Maximize the structural capacity of the concrete, avoid over designing elements.
- Minimizing the volume of the project itself. For example, question whether the additional garage is really needed or if the basement is necessary to achieve the project needs.
- Consider setting total GWP goals for the project, and allowing the concrete mix designer to have flexibility in how they achieve this goal. Specifying minimum SCM contents can place conflicting requirements on concrete suppliers, which may lead to an increase in GWP, or alter other aspects of performance. Additionally, overuse of SCMs in buildings can cause shortages of SCMs in other industries (infrastructure for example). Dams, bridges, and other large infrastructure projects often rely on SCMs to limit early thermal cracking. If SCMs are not available to those projects, additional reinforcement may be required to control cracks instead. It is important to have an understanding of availability of resources, after all the end goal is to mitigate climate change globally, and not minimize embodied carbon on one project to the detriment of many others.
For different regions in BC, the following concrete suppliers provide the lowest GWP concrete.
Supplier | Location | GWP @ 25MPa | GWP @ 30MPa | |
---|---|---|---|---|
Butler | Vancouver Island | 136 - 216 kgCO2e / m3 | 169-374 kgCO2e / m3 | https://www.butlerco.ca |
Lafarge | Canada wide | 170 - 575 kgCO2e / m3 | 195-494 kgCO2e / m3 | https://www.lafarge.ca/en |
Heidelberg* | BC | 99 - 231 kgCO2e / m3 | 162-245 kgCO2e / m3 | https://www.heidelbergmaterials.com/en |
CRMCA Industry Avg | BC | 170- 270 kgCO2e / m3 | 199-317 kgCO2e / m3 | https://concretebc.ca/wp-content/uploads/2022/10/810.CRMCA_EPD_BC.pdf |
CRMCA Baseline | BC | 219.7 kgCO2e / m3 ** | 258.9 kgCO2e / m3 ** |
Novel Materials
As plants and trees grow, they absorb CO2 from the atmosphere, a process known as carbon sequestration. Carbon accounting in forests is complex and varies between forests and forest management processes. There are uncertainties related to the amount of carbon released by the soil after felling of trees (among many other uncertainties). Current best practice is to not include carbon sequestered during the life span of virgin forestry products; however we are aligned with Builders for Climate action in our approach to carbon storing of quick growing crops. These plants have fast growth cycles, often less than one year, and are utilized within buildings for a period of time much longer than the growth time of the plant. Allowing those crops to degrade, or burning for fuel would release any stored CO2 into the atmosphere immediately, however using these within buildings allows us to delay that inevitable CO2 re-release for upwards of 25 years.
There are very limited EPDs for fast growing, plant-based products, but generic information on a few of these is shown below.
GWP [kgCO2e/m2 @RSI1] | Product | Additional Information | Source |
---|---|---|---|
-5.0 | Straw | UK industry average data | |
-3.0 | Hempcrete | https://www.hemp-works.ca/ | US industry average data |
-1.0 | Hemp fibre | ||
1.0 | Sheep's Wool | https://www.insulationshop.co/eco_products.html | |
-2.0 | Wood Fibre | https://www.insulationshop.co/eco_products.html | Gutex https://foursevenfive.ca/gutex-multitherm/ |
Key Definitions
Embodied carbon: also referred to as material carbon emissions. This is the upfront carbon associated with constructing a building. In this report, emissions stated are from life-cycle phases A1A3, the material production emissions only. Other life-cycle analysis software often includes phases A1-A5. The additional phases are related to transportation to the construction site as well as the emissions created during construction of the building.
Materials: in this report the word materials is used to mean the individual components that go into building a home, whether that’s an actual material, like wood or steel, or a component like a cladding panel that is made up of a group of materials.
Further Reading
Carbon Leadership Forum
Carbon Smart Materials Palette
KPMB LAB
Building Transparency
References
[1] Magwood, C. and Trottier, M. Nelson Material Carbon Emissions Guide. Builders for Climate Action (2022). https://www.buildersforclimateaction.org/our-work.html
[2] Magwood, C. and Trottier, M. Material Emissions Benchmark Report for Part 9 Homes in Vancouver. Builders for Climate Action (2022). https://www.buildersforclimateaction.org/our-work.html
[3] Lewis, M., Huang, M., Carlisle, S., Simonen, K., AIA-CLF EMBODIED CARBON TOOLKIT FOR ARCHITECTS PT2. Measuring embodied carbon,
[4] King, B., Magwood, C., Build Beyond Zero (2022)
[5] https://www.buildersforclimateaction.org/beam-estimator.html