From demolition to cooling: How urban renewal can become an infrastructure tool for heat risk governance and stock development

The Real Issue in Urban Renewal Is Shifting from “Demolish or Not” to “Heat and Resilience”

A study published in *npj Environmental Social Sciences* offers an angle for urban renewal that is uncommon, yet increasingly important: does demolishing informal settlements really cool cities down?

Rather than stopping at empirical judgment, the study used a difference-in-differences method, combined with Landsat thermal infrared imagery from 2002 to 2022, to track 77 demolished informal settlements and 584 control sites in Beijing, Shanghai, and Guangzhou. The results show that all three cities experienced statistically significant declines in land surface temperature after demolition, with reductions of 3.04±0.37K in Beijing, 1.09±0.27K in Shanghai, and 1.23±0.36K in Guangzhou.

The significance of this data goes beyond “demolition brings cooling.” More importantly, it suggests that urban renewal is no longer just a land development or housing governance issue, but a comprehensive infrastructure topic that simultaneously involves heat environment management, spatial form reconstruction, public service reconfiguration, and the redevelopment of existing land.

Why This Kind of Research Matters to the Infrastructure Industry

In the context of infrastructure investment and urban development, the thermal environment has long been seen as a climate or public health issue, somewhat distant from roads, drainage, electricity, or development finance. But in high-density cities, heat risk is increasingly entering infrastructure decision-making directly.

When informal settlements are demolished, the original spatial structure—low-rise, dense, poorly ventilated, and lacking green coverage—is replaced, and the city’s land cover and underlying surface conditions change accordingly. The study points out that such areas often become “heat hotspots” because of high building density, insufficient trees and vegetation, and narrow alleyways. In other words, demolition itself is not only a prerequisite for real estate redevelopment; it may also be part of the city’s heat management system.

This also explains why many urban renewal projects ultimately do not simply involve demolition and rebuilding, but are accompanied by road paving, drainage systems, green belts, public spaces, and more organized building layouts. Together, these elements affect urban ventilation, albedo, surface heat storage, and thermal comfort.

From Case Effects to System Logic: Why Renewal Increasingly Resembles Infrastructure Investment

What makes this study worth attention is that it emphasizes causal identification rather than simple correlation. Previous studies often relied on before-and-after comparisons or cross-sectional spatial analysis, but such methods struggle to separate three confounding factors: ongoing urbanization, climate change, and policy overlays.

For infrastructure research, this is especially critical. Urban renewal projects have never happened in isolation; they are usually carried out alongside land concessions, area development, transit introduction, public facility upgrades, sponge city construction, and functional reorganization of districts. Without controlling for these background variables, it is difficult to determine whether the cooling effect comes from demolition itself or from the broader urban transformation process.The study adopts a difference-in-differences framework precisely to identify, as much as possible, the net effect of the “demolition” intervention. This methodological shift also reflects a trend in urban infrastructure research: more and more urban governance actions are being treated as measurable, attributable, and assessable spatial engineering projects, rather than merely administrative renewal.

Informal settlements are not peripheral areas, but the revealing surface of the costs of urban expansion

The importance of the samples from Beijing, Shanghai, and Guangzhou lies in the fact that they represent a typical spatial phenomenon in the rapid expansion of China’s megacities: after rural land is absorbed by urban boundaries, transitional neighborhoods emerge that lie between formal development and informal residence.

Such areas are not uncommon in cities of the Global South. As noted in the introduction, loteamentos in Brazil, kampongs in Indonesia, and other informal settlement forms in rapidly urbanizing regions all reflect a similar mechanism of urban growth: inadequate formal infrastructure supply, with housing demand coming first and governance and redevelopment following later.

From a long-term development perspective, this shows that urban renewal is not as simple as “clearing out the old urban core”; it is about addressing the historical debt accumulated in the course of urban expansion. Informal settlements often concentrate low-income mobile populations, with complex property rights, insufficient public services, and weak infrastructure, but they are also the interface where contradictions among urban land value, population mobility, and spatial efficiency are most concentrated.

Therefore, demolition is not just a substitution of form; it is also the city redefining land use, public investment priorities, and the boundaries of future growth.

Behind the cooling effect are ventilation, greening, and infrastructure reorganization

The study’s findings show that after informal settlements were demolished, all three cities experienced cooling, but to different extents, indicating that urban form, geographic conditions, and renewal approaches all alter the outcome.

Beijing saw the largest cooling effect, while Shanghai and Guangzhou were smaller. This difference is not surprising, because the density structure, climatic conditions, renewal pathways, and surrounding land-use patterns of different cities all vary. For the infrastructure industry, this means heat governance cannot rely on a single template for replication; it must be designed in coordination with district development, road grids, building-height controls, green-space allocation, and drainage systems.

If traditional urban renewal focused on floor-area ratio, land value, and balancing demolition with construction, then today’s urban renewal must also incorporate thermal comfort, walkability, continuity of public space, and adaptation to extreme climate into its engineering objectives. Especially against the backdrop of increasing heatwave frequency, cooling is no longer just an environmental benefit; it also affects residential stability, labor efficiency, and public health expenditures.

What this means for PPPs, district development, and the allocation of public capital

From the perspective of project financing, such research is quietly changing the returns structure of urban renewal projects.In the past, the investment logic of urban renewal revolved more around land value appreciation, residential development, and commercial redevelopment; today, if heat risk, resilience improvement, and public health benefits are incorporated into project evaluation, the composition of project value becomes much more complex. Roads, green space, drainage, community public spaces, and building restructuring are no longer merely supporting costs, but may become core capital expenditures that enhance the quality of urban assets and the stability of long-term operations.

This also means that more urban renewal projects in the future will be advanced in a portfolio-based manner:

• In the early stage, the focus may be on demolition and land consolidation;
• In the middle stage, infrastructure gaps will be filled, including roads, water supply and drainage, and power facilities;
• In the later stage, long-term returns will be realized through development, operations, and public space maintenance.

If city governments hope to link renewal with climate adaptation, heat risk management, and livelihood improvements, then the scope for PPPs, land consolidation financing, integrated district development, and coordinated investment in public facilities will all expand. In other words, demolition is no longer merely a clearance action, but may become the starting point of a type of “urban environmental infrastructure.”

From Urban Renewal to Heat Governance, the Infrastructure Evaluation System Is Changing

The most valuable aspect of this study is not that it proves demolition will definitely cool things down, but that it reminds policymakers: urban renewal needs to be incorporated into a broader infrastructure evaluation system.

Within this system, the assessment criteria should not be limited to how much is demolished and how much is built, but should also include:

• Whether local heat exposure is reduced;
• Whether ventilation and green coverage are improved;
• Whether the continuity of public space is enhanced;
• Whether the long-term vulnerability of high-risk, low-service areas is reduced;
• Whether synergies are formed with drainage, power, roads, and housing systems.

This line of thinking is consistent with global trends in the infrastructure sector: climate adaptation is beginning to enter the core asset logic of urban development, and heat resilience, together with drainage resilience, transport resilience, and grid resilience, is becoming an important indicator for measuring a city’s long-term competitiveness.

Conclusion: Demolition Is Just an Action; the Real Variable Is How a City Reorganizes Itself

If viewed only on the surface, this study discusses temperature changes after the demolition of informal settlements; but from a broader infrastructure perspective, it is really about how cities adapt to rising heat risk, changing population density, and the transformation of development models through spatial reorganization.

In the cases of Beijing, Shanghai, and Guangzhou, demolition is not the end point, but a node in the city’s reconfiguration of land, infrastructure, and environmental performance. For planners, investors, and engineering firms, what is truly worth paying attention to is not the short-term changes of demolition versus construction, but whether urban renewal can create a higher-quality infrastructure network, a more stable thermal environment, and a more sustainable development structure.

This is also why urban renewal is increasingly becoming a long-term infrastructure investment rather than a one-off land operation.

SEO DescriptionBased on the latest research from *npj Environmental Social Sciences*, this article analyzes from the perspectives of infrastructure and urban development why the demolition of informal settlements may lead to urban cooling, and how this outcome may reshape the long-term logic of urban renewal, heat risk governance, PPP development, and the redevelopment of existing land.

Information Source URL

https://www.nature.com/articles/s44432-026-00009-1