Op-Ed: Embodied Carbon—Regulating to Reduce
As Denmark has recently tightened its standards for new construction with the aim of reducing embodied carbon, what lessons can Canada draw from this experience?
In 2023, the Danish Building Code made life-cycle assessment (LCA) mandatory for all new buildings over their first fifty years, initially capping CO₂ emissions for buildings larger than 1,000 m² at 12 kg/m²/year.
Since July 1 of last year, this average limit has been lowered to 7.1 kg/m²/year and extended to new buildings of various uses, from secondary homes to public institutions and office buildings.
Danish regulations
“The Danish government worked very close with researchers [from the Built Environment Department (BUILD)] at Aalborg University : they did an estimate of new builds, how much CO2 is there from materials and how much CO2 is on the building site ” explains Thomas Graabaek, architect and founder of Formfaktor, a Danish software development and distribution company specializing in BIM. “They also developed an LCA calculator that worked with the Danish laws and the research behind it : It was given away for free to all architects and engineers ” he recalls.
The government also mandated researchers to provide practitioners with a list of generic material data for cases where an Environmental Product Declaration (EPD)—required to perform an LCA—was not available.
When the regulation came into force in 2023, the entire construction industry was opposed to it, recalls Thomas Graabaek. “ And then slowly there was a movement within architects and engineers that actually we need to have even stricter demands.”
In collaboration with an architectural firm, and with two students from the Technical University of Denmark, he also created a plug-in module for BIM design software that allows architects to calculate LCA directly from model data: DesignLCA. This tool now makes it possible to perform calculations at the earliest design stage, ensuring that projects comply with regulations from the outset.
And in Canada?
“Unfortunately, in Canada, [architects] have been educated only around operations, [not on its entire life cycle],” explains Kelly Alvarez Doran, architect, co-founder of Ha/f Climate Design, and adjunct professor at the University of Toronto. “If we look at the whole cycle, we see that the production stage is the worst for the emissions.”
In 2014, Mr. Alvarez Doran worked with MASS Design Group on the construction of a primary school in Ilima, a remote village in the Congo that is difficult to access from major cities. He had to rely on local labor and materials to design the school. “These projects are an opportunity to redirect most [of the project budget] back into the community,” he adds.
Researchers at MIT later calculated that the amount of embodied carbon generated by the construction of this primary school was 28 times lower than the global average for education projects.
Upon returning to Canada, he decided to calculate the embodied carbon emitted by a cottage he had built a few years earlier for his in-laws in Ontario. “What I thought was a wood-frame house was in fact, like most houses in Canada, a concrete foundation with a wood structure on top,” he says wryly. “Sixty-five percent of the emissions were generated by the foundation, particularly reinforced concrete and extruded polystyrene.”
The Toronto example
As part of a workshop he taught in the fall of 2020 at the University of Toronto, he analyzed several types of buildings across the Greater Toronto and Hamilton Area, ranging from multi-unit residential buildings to university pavilions. After reviewing regulations implemented elsewhere, he wrote an open letter in Canadian Architect advocating for the adoption of embodied-carbon benchmarks and targets in building standards and policies.
Using the data collected with his students, he helped the City of Toronto integrate requirements related to upfront embodied-carbon emissions (associated with the manufacturing, transportation, and installation of a building’s main components) in 2023. Thresholds for new City-owned buildings must now be below 350 kg CO₂e/m². For the time being, requirements for private buildings are voluntary, but a future revision of the standard could expand their scope.
In Denmark, the transition period between 2023 and 2025 was intended to give built-environment professionals—particularly those in smaller firms—time to learn how to carry out LCAs.
“Many of them preferred to pay consultants […] since the results didn’t initially matter, but now [that a limit has been imposed on all buildings], So I think now they wish that they had to..”
Through Ha/f Climate Design, Mr. Alvarez Doran also made recommendations to the City of Toronto that led to the revision of mid-rise building guidelines in 2024. These included discouraging underground construction—which has a disproportionately high carbon footprint and exposes buildings to increasing flood risks—establishing minimum requirements for bio-based materials in façade systems, and encouraging material reuse as well as design for deconstruction.
According to Thomas Graabaek, Danish regulations now allow recycled materials to be counted as having zero impact in a building’s LCA, in order to encourage their use.
Designing differently
“I think that as architects, we need to redefine what we think is beautiful at the core of it” says Kelly Alvarez Doran. “Expansive reams of curtain wall glass is not beautiful when you actually understand its [environmental] impact both upfront and operationally.” In his view, reducing both the environmental and financial costs of a project requires designing buildings with less complex forms.
He also advises all designers to ask manufacturers for their EPDs. “They’re not expensive to do, and it allows manufacturers to look at their own supply chains and make better decisions,” he says.
For example, during his collaboration with the City of Toronto, Kelly Alvarez Doran conducted an LCA on a project that was already at an advanced design stage—the Toronto Paramedic Services Multifunction Station No. 2. Simply by replacing certain materials with alternatives offering similar performance, such as insulation, cement types, and sealants, the team managed to reduce the building’s embodied-carbon emissions by 800 tonnes, at no additional cost.
In Denmark, the client now bears the cost of the mandatory LCA, according to Thomas Graabaek. But for Kelly Alvarez Doran, this cost can easily be offset. “The materials that increase a building’s carbon footprint are the same ones that increase its cost,” he concludes.
To reduce a building’s carbon footprint, Mr. Alvarez Doran encourages the use of local and bio-based materials: “Why are we not using structural stone again [in Quebec] as they are now in France and England, for example?”
Finally, he advocates for the establishment of embodied-carbon targets at different regulatory scales. “Denmark is a small country,” he acknowledges. “In Canada, we should [push for regulation] city by city and province by province.”
“Even if it isn’t perfect, this new regulation has really turned the whole industry in a much more sustainable direction.,” says Thomas Graabaek. “Everybody now wants to be part of it.”
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