Circular design: making the most of what’s already there to reduce carbon impact
September 21, 2026
In interior design, reducing a project’s environmental footprint is not only about choosing more responsible new materials. Another approach deserves equal attention: preserving and reusing what is already there.
This circular design approach was central to the design of Bentley Systems’ Québec City offices. Rather than treating the existing space as something to erase and start over, we looked closely at what could be retained, reused and integrated into the new design.
Reuse as a design strategy
Preserving existing materials can have a significant impact on a project’s environmental footprint.
For the Bentley Systems offices, this approach reduced GHG emissions associated with embodied carbon by approximately 40% compared with an entirely new interior fit-out.**
Glass partitions, gypsum board, carpeting, acoustic ceiling tiles and light fixtures were the elements with the greatest impact on the project. Without the design decisions that made their reuse possible, the project’s environmental footprint would have been considerably higher.
Overall, the approach avoided 25 tonnes of CO₂ equivalent.* Based on the equivalencies used in the assessment, this represents approximately 100,000 km travelled in an average gasoline-powered car, or the carbon captured by some 415 young urban trees over ten years.
In sustainable design, measuring the impact of our decisions is essential to learning from them. For this project, the embodied carbon analysis helps us identify, in very concrete terms, which reused materials deliver the greatest value.
These results make tangible an idea that can otherwise seem abstract: decisions made early in the design process can have a measurable impact on the carbon footprint of an interior space.
Making what’s already there a design resource
Circular design also requires us to look differently at what is already in place. It means carefully assessing the technical, design and economic potential of existing spaces. Which materials can continue their life cycle? Which elements can be adapted to new uses? And how can they be integrated into a coherent new composition?
Reuse does not mean compromising design intent. Rather, it calls for a different way of designing: working with what exists, revealing its potential and giving it new value.
Designing with what already exists doesn’t mean doing less. It means exploring how existing elements can fully contribute to a new design intent. That constraint can become a creative material in its own right.
This approach also has an economic dimension. When an existing element can adequately meet the project’s needs, retaining it can avoid certain purchases of new materials as well as the work required to replace it. Potential benefits must, however, be assessed within the specific context of each project.
Measuring to design better
At STGM, sustainability becomes tangible when it translates into responsible decisions and measurable results.
The design of Bentley Systems’ offices demonstrates the value of a reuse-based approach. Making the most of what is already there extends the life cycle of materials and reduces the need for new ones. The team balanced environmental responsibility with the realities of the project while creating high-quality spaces.
Discover the full Bentley Systems office project in Québec City →Bentley office renovation in Quebec City
*Comparative data from a Carbon Leadership Forum study.
**GHG assessment conducted using One Click LCA and covering modules A1–A3 of the life-cycle assessment.