To meet global climate targets, the construction industry must drastically reduce greenhouse gas emissions—by over 90% within the next two to four decades. This isn’t just a matter of future planning; it’s a critical requirement for keeping global warming below the 2°C threshold outlined in the Paris Agreement. The challenge is immense, given current housing deficits across major economies, but feasible.
The Scale of the Problem
Globally, construction accounts for 10-20% of all greenhouse gas emissions, largely due to cement production. However, many cities and nations lack even basic estimates of their construction-related emissions. This gap in knowledge makes effective planning impossible. A recent study by researchers at the University of Toronto analyzed 1,033 cities, revealing a severe lack of data on construction emissions at the municipal level.
Solutions: Efficiency and Material Choice
The solution isn’t simply switching to “green” materials like wood. While wood can reduce emissions compared to cement, its sustainability depends on optimistic assumptions about forestry growth. Instead, prioritizing efficient building design is more effective. Reducing wasted space and unnecessary structural elements can significantly lower emissions.
Furthermore, construction emissions must be considered over a building’s entire lifecycle, including operational energy use. Designs that promote natural ventilation and minimize energy consumption are crucial. The researchers found that cities have significant control over construction emissions but often lack the resources to measure and manage them effectively.
Rethinking Housing Priorities
Meeting housing demand through single-family homes will push cities over their carbon budgets. The analysis suggests focusing on multi-unit housing as a more efficient alternative. Moreover, countries must re-evaluate construction priorities. For example, Canada could accommodate millions in new housing without increasing emissions if it scaled back oil and gas infrastructure projects.
The Bottom Line
Reducing emissions from construction is non-negotiable if the world is to meet the Paris Agreement goals. Cities have the capacity to act but must first assess their emissions, then implement radical changes in building design, materials, and overall construction priorities. Without this shift, even zeroing out other sectors won’t prevent dangerous levels of warming.
