Architectural Design Plays a Key Role in Combating the Climate Crisis
Globally, the construction sector consumes more virgin natural resources than any other human activity. It is responsible for half of the world’s annual raw material use, leading to massive climate emissions. In Finland, as in many other countries, construction accounts for about one-third of annual emissions. According to the IPCC, the building sector must reduce its climate emissions by 80–90 percent by 2050.
“The 1.5-degree climate goal is no longer realistic. We may still stay within 2 degrees, but that won’t happen without a sustainability transition in the construction sector. Reducing resource use is the biggest challenge,” says Professor of Sustainable Construction Matti Kuittinen from Aalto University.
The current state of building design and construction is far from sustainable, making future trends even more concerning. Resource consumption is increasing, not decreasing. The main driver is population growth: by the end of the century, the world’s population will be 2–3 billion higher than today—people who will all need homes, schools, roads, and infrastructure.
Additionally, extreme weather events and natural disasters are intensifying, damaging the built environment. Reconstruction, repairs, enhanced maintenance, and protective infrastructure all demand vast resources. Material consumption is growing even faster than the population.
“Reducing resource consumption is no easy task in these circumstances. The equation is very difficult, but still solvable. Legislation should be developed vigorously, as the market-driven transition to sustainability is neither sufficient nor fast enough, says Kuittinen.
In addition to national legislation, international regulation is urgently needed. At the COP29 climate summit in Baku (2024), a petition coordinated by Aalto University and signed by international researchers called on world leaders to implement building-related emissions legislation in every country within the next ten years.
A Copernican Revolution
Public debate on sustainable construction often focuses on details such as energy efficiency, leaving major issues of principle unaddressed. New construction should no longer be the starting point for building design. Kuittinen is introducing a new hierarchy to architecture and construction, in which the highest goal is to avoid building anything new. The aim is to make the most of existing buildings, either as they are or with minor alterations. The second-best option is to renovate the premises to suit their intended use, and the third is to extend the building.
“New construction should be the last resort. And if it must happen, spaces should be designed for multiple functions. New buildings should be multipurpose and easily adaptable,” says Kuittinen.
In addition to the intended use, sustainable building design must take into account factors such as the location and life cycle of the building. Buildings in city centers should be designed to be easily adaptable and to last for centuries, while service buildings constructed for declining populations in remote areas, for example, should be relocatable. Log houses, for example, have traditionally been moved to new building sites in Finland.
“- If it is not known whether a building will be used in the future, it should be designed so that it can be converted, moved in parts, or dismantled for reuse if necessary. The purpose and location of a building determine what is sustainable for building sites, he adds.
After usability, the next most important factor is size. Smaller buildings require fewer materials and consume less energy.
“- I don’t mean that everyone should squeeze into tiny houses, but even a 10 percent reduction in floor space has a significant impact over the life cycle of a building. Better design could improve the quality of the space while reducing the square footage,” Kuittinen says.
From Wastefulness to Circular Economy
To improve the sustainability of new construction, the priorities are: make buildings multipurpose, reduce their size, and only then focus on energy and material efficiency. Kuittinen argues that construction should use either recycled materials or those that have sequestered carbon. The use of renewable bio-based materials—such as wood, willow, and hemp—would support sustainability. Promising technologies also bind captured atmospheric CO₂ into construction materials like concrete.
Building within planetary boundaries requires an almost closed-loop circular economy, Kuittinen states. Construction projects should maximize the use of reused components. A comparison between EU countries shows Finland is doing poorly: it leads in raw material consumption but ranks last in construction and demolition waste recycling. A longer building lifespan is also better for circularity. Yet in Finland, buildings are typically demolished after just 50 years — even in growth areas.
“Ten years ago, 4,000 buildings were demolished annually. Now it’s 8,000. This is not a good direction. If a building can’t be repurposed, we should consider reusing its frame or foundations,” Kuittinen says.
The high demolition rate combined with low recycling is unsustainable. With a circular mindset, deteriorating neighborhoods in shrinking areas or outdated service buildings could become material banks rather than burdens.
According to Kuittinen, the construction sector should be brought under climate-based taxation. A comprehensive emissions-based tax system for materials would make high-emission materials significantly more expensive, encouraging builders to choose sustainable options. A strong enough financial incentive would accelerate the transition
“- The younger generation of designers is very aware of these issues, which is encouraging. But in mainstream construction, idealists are still crushed under time and budget pressures.”
The climate crisis and the sustainability transition are already receiving attention in architecture and design education. Kuittinen emphasizes the need to teach systems thinking and foster understanding of how building impacts the environment and society. Designers also need practical tools to conduct proper lifecycle assessments that support sustainable choices.
On a global scale, Finland is a stable country in terms of population growth and natural conditions, and its inhabitants live mainly in prosperity – is continued new construction justified here?
“It’s not fair. Finland is skilled, creative, and resource-rich—we should lead by example in building within planetary limits,” Kuittinen concludes.The article and interview are based in part on Matti Kuittinen’s talk Building within Planetary Boundaries (10/2023), available on Aalto University’s YouTube channel.
AUTHOR: Saana Katila