The “Talk series – Porto Towards Carbon Neutrality 2030” is an initiative organized by the Porto City Council, which includes 10 clarification and debate sessions related to the themes of sustainability, decarbonization, and climate transition in the context of cities’ carbon neutrality. The third session took place last Thursday, May 18, at the Porto Innovation Hub and had as its theme “Decarbonization of Construction.”

Bento Aires, President of the Order of Engineers of the North Region, was the moderator of the event, which featured Francisco Rocha Antunes, Director of Development at + urbano; José Gomes Mendes, Executive Director of the Casais Foundation; and Humberto Varum, Full Professor at FEUP.

Each of the speakers had the right to an intervention, followed by a space for debate and clarification with the audience.

The session opened with the Vice-President of Porto City Council, Filipe Araújo, who highlighted the changes that are happening in the construction industry and how Portuguese companies are looking to the future: “We talk a lot about paradigm shifts, but when we talk about the future of construction, I believe we are really going to witness a giant leap. It is very good to realize how Portuguese companies are looking at this future and, I hope, this future is very much linked to the development of Porto,” said Filipe Araújo.

“Construction is in a phase of change. Almost 40% of carbon emissions are linked to construction, which is undergoing a maturation process to respond to this,” began Bento Aires, introducing the theme of the event.

Lack of funding as a brake on emissions

Francisco Rocha Antunes, Director of Development at + urbano, brought to the discussion the challenge of lack of financing, which will be a reality for the more polluting construction of buildings: “By January 2026, all real estate projects that are not aligned with sustainable development goals will cease to have bank financing. They can be made, but they do not have financing”.

The director of + urbano explained that this decision stems from the decision of the European Central Bank (ECB) to align its decarbonization and sustainable development objectives with the financing rules of the European Union. Francisco Rocha Antunes mentioned that this alignment is crucial to boost the decarbonization of the real estate sector, adding that the construction industry is, certainly, the most conservative industry on the planet.

“There are, at this moment, sectors of the economy that no longer have access to bank credit, cannot make a renting or leasing contract, nothing. This is because they are what is called “brown sectors” of the economy, that is, they are the sectors most linked to the commercialization of fossil fuels. And, after the brown ones, comes the gray sector, in which construction falls in,” he continued.

In this sense, the director of Development at + urbano highlighted the importance of replacing construction materials with higher CO2 emissions. “Concrete and steel can only be used for what cannot be done otherwise. Everything else has to be done in another way. We are far from it and we have to be quick because the calendar is against us. We all, professionals of this industry, have to be open to change,” he said.

Promotion of circularity in construction

In turn, José Gomes Mendes, Executive Director of the Casais Foundation, focused his intervention on promoting circularity in the construction sector. The Casais Foundation’s director highlighted the importance of reintroducing resources into the economy, reducing the financial and environmental cost of waste disposal and constant material extraction.

“Extraction, besides depleting cultural heritage, is also very costly for the environment. Everyone thinks that the combustion process generates a lot of CO2, and it’s true, but nobody thinks about the environmental damage and CO2 emissions in the extraction process,” he warned.

José Gomes Mendes explained, therefore, that “reducing the amount of materials used and extending the useful life of buildings” is extremely necessary to promote circularity. In addition, the director of the Casais Foundation also mentioned the longevity of buildings as a goal that should be on the minds of all players in the construction industry, as well as the concern to build low-carbon buildings.

“How can I have a building with zero emissions? High carbon intensity materials are out, but low carbon intensity materials have to be there because it is not possible to have only decarbonized materials. So how is this achieved? Through the offsetting of these materials. I have to put there materials that have sequestered carbon before entering the building. They already bring credit, they have negative emissions, such as wood,” he explained.

For the director of the Casais Foundation, the change will have to go through the four sectors “that make the needle move,” namely the food sector, manufacturing processes, the construction environment, and mobility and transport. “We need to act in the sectors that have the greatest impact. Changing niches is good, but it will not make the necessary difference for the urgency of the problem,” he assured.

The weight of construction and transportation on Porto’s emissions

In the final intervention of the event, Humberto Varum, Full Professor at FEUP, addressed the importance of analyzing the emissions from construction and transportation in the city of Porto.

The FEUP professor also stressed that, when discussing decarbonization in the construction sector, it is essential to consider not only buildings but also the people involved, namely the end users, the real estate agents, the people involved in the construction itself and the project. Humberto Varum emphasized the need for joint work to reduce emissions and achieve carbon neutrality.

The concern and dynamism that the municipality of Porto has shown in anticipating the goals of the European Commission were praised. And for this to become a reality, the professor warned of the need for further advances not only in the construction sector but also in transportation. “Municipal assets generate 6% of GHG from the entire city of Porto. Within the city’s total emissions, residential and commercial buildings generate 50% of the total, and transportation generates 40%. These are, in fact, the two major vectors that we have to attack.”

Improvements in the efficiency of transportation networks, investment in residential photovoltaic systems, in multi-family buildings and infrastructure; the focus on natural materials, particularly wood; the acquisition of sustainability certificates; the establishment of relationships between construction participants and universities; and also investment in rehabilitation, were some of the solutions presented by the professor to face this challenge.