Architects, engineers and civic planners spend much of their time and talents on building the city of tomorrow, possibly losing sight of the fact that viable infrastructure already exists. While building better with smart technologies, eco-friendly construction materials and interconnected systems is essential for preserving natural habitats and slowing climate change, perhaps it’s time to shift focus to finding solutions for existing structures. Could sustainable urban renewal be the solution?
Urban Areas Need Comprehensive Retrofitting
Aging infrastructure exists in almost every city worldwide. These outdated buildings, roads and pipelines aren’t just potential safety hazards — they adversely affect the local environment and communities.
It’s no secret the built environment contributes to climate change. According to the United Nations, it is responsible for 60% of all greenhouse gas emissions, making it one of the most significant contributors. Aging structures pose a particularly substantial problem because they are far more energy-inefficient and resource-intensive than their modernized counterparts.
Ultimately, inefficient building systems and unsustainable construction materials are the primary culprits. For instance, steel emits 15% more greenhouse gases and produces 300% more water pollutants than wood and concrete a staggering 225%. Even though civil engineers have recognized this problem, their sustainable development efforts are only a partial solution — countless aging, unsustainable structures still exist.
Continuously retrofitting existing infrastructure is the only way to make urban areas comprehensively sustainable and climate resilient. Replacing, renovating or refurbishing outdated architecture is the most straightforward path toward a net-zero future.
The Case for Continuous Sustainable Urban Renewal
Traditional urban renewal involves seizing and demolishing large swaths of public and private property to address urban blight — the worsening physical deterioration of abandoned buildings and vacant lots. City planners use public investments to revitalize economically downtrodden areas.
The problem with this approach is that tearing structures down when they get too old or run down is wasteful. While the recovery rate of construction and demolition waste is increasing as more contractors become aware of the value of reuse and recycling, demolishing structures should not be any city’s go-to strategy.
Sustainable urban renewal prioritizes retrofitting and renovating structures instead of tearing them down, providing an end-to-end solution for real estate. For example, engineers may replace an inefficient air conditioning system in a decades-old apartment with a geothermal heat pump or natural, passive ventilation.
Upgrading electrical, plumbing, fire safety and HVAC systems makes structures more energy-efficient. Moreover, replacing deteriorated or unsustainable construction materials with eco-friendly alternatives helps preserve the environment.
Such regeneration efforts are ongoing. Instead of waiting for buildings to reach a state of decay or become abandoned again, civil engineers, construction workers and architects continuously install upgrades and replacements. They maximize efficiency while mitigating climate change contributions.
Urban Regeneration Benefits People and the Climate
Continuous sustainable urban renewal reduces greenhouse gas emissions while resulting in extensive physical, social and environmental benefits. For one, it mitigates demolition-related pollution, improving locals’ well-being. It also prevents functional deterioration, ensuring neighborhoods and public spaces remain livable and usable.
Climate Resilience
Sustainable urban renewal fosters climate resilience. City planners can use reports to decide what to prioritize, ensuring they consistently reduce greenhouse gas emissions. For instance, since a single mature tree can absorb over 48 poundsof carbon dioxide annually while creating an oxygen-rich environment, the data may show a green building retrofit is ideal.
Biological Diversity
Sustainable building retrofitting can make infrastructure complement its natural environment by incorporating plants and geological structures into the architecture. This approach creates shade and livable habitats, supporting essential biological diversity. For example, the vegetation covering a green building can attract wildlife like birds and bees.
Resource Conservation
Urban regeneration efforts preserve historical structures and prevent obsolescence. The fewer projects construction companies have to work on, the more resources they save. When retrofitting buildings, they can use eco-friendly materials instead of resource-intensive alternatives like steel or concrete.
Moreover, energy-efficient retrofitting projects can reduce the electricity buildings use to power essential systems. For example, installing rooftop solar panels on an aging apartment complex offsets inefficient systems and reduces reliance on the grid.
Case Studies Proving the Value of Building Retrofitting
The value of building retrofitting isn’t hypothetical. Already, multiple homeowners, construction companies and local governments have embraced this concept. Even if a city doesn’t officially adopt this strategy, individual contributions can make a difference.
Forrest Meggers, an associate professor of architecture at Princeton University, is one such person. Over the past three years, he has invested over $340,000 into a continuous, whole-home retrofitting project, overhauling most of his home’s core systems. He has improved his home with rooftop solar, water storage and a geothermal heat pump.
Energiesprong — an energy-efficient retrofitting project in Europe — took a similar approach. Using cutting-edge technologies, professionals adapted apartments’ electrical systems. As a result, overall electricity consumption lowered by 70%, averaging 150 kilowatt hours per square meter. Within 30 years, these buildings will reach net-zero.
These are only two examples of sustainable urban renewal. Since retrofitting requires extensive planning — and can get expensive — few large-scale projects exist. Dealing with the red tape of modern building codes and utility regulations when working on a decades-old structure can be complex. For this reason, it isn’t a standard practice yet.
For reference, in the global north, retrofitting rates were 1% of building stock in 2022. That figure must triple for the world to achieve decarbonization by the end of the century, requiring a $3 trillion investment. Retrofitting is a formidable undertaking even in high-growth urban areas — places where new construction could double building stock by 2050.
Retrofitting Buildings Is Essential for Building Better
Building retrofitting is vital for future-proofing existing urban areas, making cities more livable and mitigating the adverse effects of climate change. Going forward, professionals should learn from successful case studies. Instead of demolishing structures and landfilling the waste, they should use cutting-edge technologies and renewable energy.
