We analyzed twenty-six projects – ranging from 9,000 m² to 115,000 m² – to calculate our firms Embodied Carbon intensity (ECI) in 2025. These projects varied in building typologies and the chart below summarizes the key ECI measurement compared to primary building use (data point colour), the building height (x-axis), and the size of the project (shown by the data point size). We highlighted this in our December 2025 OnTrack article.

ECI – measured in kgCO₂e/m² — represents the greenhouse gas emissions associated with material extraction, construction, and demolition. It is provided per unit area to create a functional unit allowing comparisons of projects across different scales. A large percentage of our projects analyzed consisted of reinforced concrete structures across BC.

Data Deep Dive

Collecting the overall average intensities is helpful to measure the efficiency of the projects we are involved with. However, the real goldmine lies within the metadata and detailed exports for each project. Our hope is that we can identify trends and develop specific structure-focused embodied carbon reduction strategies for future projects.

Three key elements stood out to us when reviewing the data:
1. Basement size / non-GFA area
2. Building Height
3. Building Transfers

One of the things you will notice about the three points above is that they are all determined in the early phases of a project’s design. Early coordination and collaboration between owners, architects, and engineers can manage these elements effectively.

Basement Size

Given that the ECI metric is often per unit area of habitable space (residential and commercial usages), the ECI intensities are very dependent on the amount of built area allocated to other usages:

• Parking basements
• Outdoor landscape and amenity areas
• Roof structures
• Storage and MEP areas

As expected, if more of the structure aligns to the key functional usage, the project will use less material for the same result and will have a lower ECI:

This highlights a couple of known embodied carbon reduction strategies:

• Consider the parking needs for the project to reduce the large amount of material required for basement structures.
• Consider the massing of the project to maximize the gross floor area over the basement below to avoid large roof areas over parking and podium structures.

Building Height

One of the most interesting findings within our data suggests there is an optimal height for high-rises within BC. Many of our projects sit within 25-35 above-grade floors and have a close group of lower ECI:

Our thoughts on why this might be the case:

• These types of structures often end up with efficient 3-bay elevator cores, the plan dimensions of these circulation cores balance the seismic strength and stiffness demands efficiently, reducing the ECI associated with shear walls.
• Additionally, in BC, this height of building balances the wind and seismic forces effectively which leads to less material associated with the shear walls and foundations. Shorter buildings can be more stiff and can attract a larger proportion of their mass in an earthquake. Taller buildings must manage accelerations under wind effects to make sure the occupant is comfortable.
• The foundation ECI for projects of this size typically have much lower foundation ECI. This could be a combination of the building weight vs overturning, or be due to the efficient layout that we typically see on single point towers.
• ECI for shorter buildings (<15 floors) can be significantly skewed by changes in the GFA ratio mentioned earlier, poor ground conditions, or inefficiencies in the lateral system.

Building Transfers

When building usages result in column grids not being able to stack, we must design structural transfer elements to move column loads between these mismatched columns. As these often occur near the base of the building (e.g. where residential column layouts do not suit commercial or parking layouts), these can be very significant. For a 30-storey concrete building, this could involve 1m to 2m deep concrete transfer slab, which incurs a significant embodied carbon impact.

The chart below compares the ECI contribution from the transfer slab itself on the X axis to the overall project ECI on the Y axis:

It is evident that the additional transfer ECI results in a higher overall project ECI. This is not only due to the inherent ECI in the transfer structure, but also the knock-on effects from the increased mass at that level (larger shear walls, columns, and foundations).

It won’t be a surprise to hear that a lot of our initial input in a project revolves around minimizing transfers to save money and help maintain the construction schedule. Now, we can also show that there is a significant embodied carbon reduction too – somewhere in the range of 20-60 kgCO₂e/m² or 5-10% of the project’s ECI.

Wrap up

Embodied carbon performance is shaped early; our findings reinforce that early coordination has measurable carbon consequences. We hope this gives an idea of some of the insights we are looking to learn and share with the wider community.

Remember: keep the basements small, landscapes on native soil, and avoid transfer structures where possible. This will reduce both the cost and ECI of the building.

We welcome the opportunity to discuss how these patterns can inform future projects, so please do not hesitate to get in touch with us if you would like to dive deeper into these findings.

Written by Rory Roberts – Director of Sustainability

Together, we can contribute to a more sustainable built environment. If you are interested in sustainability and would like to discuss any of the topics in this article, please get in touch with us at [email protected].

For more information on our sustainability initiatives and to stay updated on our latest projects, visit our website and follow our OnTrack blog series.