From Housing Boom to Resilience: Why Today's Building Choices Will Shape Global Risk to 2100

Global housing stock could nearly double to 4.1–4.55 billion units by 2100, while exposure to floods, earthquakes, storms and extreme heat rises sharply. Investing early in resilient construction, safer land use and stronger building standards could reduce replacement costs and protect governments, communities and investors from escalating disaster risks.

The world is approaching an unprecedented housing construction challenge that could reshape cities, public finances and disaster risks for decades. A World Bank study covering 181 countries projects that global housing stock could rise from about 2.46–2.48 billion units in 2025 to between 4.10 billion and 4.55 billion by 2100. The findings suggest that governments must look beyond simply increasing housing supply and focus on where homes are built, how long they last and whether they can withstand floods, earthquakes, storms and extreme heat.

The challenge is already substantial. The study cites a housing deficit of around 268 million units affecting 1.26 billion people across 64 emerging economies, while more than one billion people live in informal settlements. Future demand will be shaped not only by population growth but also by shrinking household sizes as incomes, demographic structures and living arrangements change.

Africa and South Asia Face the Biggest Housing Expansion Challenge

Regional differences will determine where investment pressures become most severe. Sub-Saharan Africa's housing stock could increase nearly fivefold by 2100, reaching approximately 1.12–1.37 billion units. Housing stock in the Middle East and North Africa could expand by 167–225 percent, while South Asia could record growth of 105–144 percent.

East Asia and the Pacific faces a different challenge. Its housing stock is expected to peak around 2040 before gradually declining as populations age and fertility falls. Europe and Central Asia may experience little net housing growth, but governments will still need significant investment to replace aging and obsolete buildings.

Importantly, an estimated 20–50 percent of housing expansion could take place on land that is undeveloped today. This allows governments to guide growth toward safer locations while providing roads, electricity, water, sanitation and public transport before settlements become established.

Stronger Homes Today Could Cut Tomorrow's Replacement Bill

Construction quality could determine how expensive the housing challenge becomes. The study assumes an average lifespan of around 20 years for fragile housing, compared with 40 years for median-quality structures and 60 years for robust buildings.

Under business as usual, annual replacement requirements could reach approximately 100–122 million housing units by 2090–2100. A resilient construction pathway could reduce annual replacement demand by around 34–40 percent because better-quality buildings remain usable for longer.

Resilience costs more initially. However, in most regions, annual expenditure under the resilient pathway eventually falls below business-as-usual construction costs, generally between 2060 and 2070.

The situation is more difficult in South Asia and Sub-Saharan Africa, where massive construction volumes mean resilient housing can remain more expensive throughout much of the century. Yet the study's calculations do not include avoided disaster losses, lower maintenance costs or wider welfare gains, meaning the full economic benefits of resilient housing could be greater than the construction-cost comparison suggests.

Extreme Heat Could Become the World's Biggest Housing Threat

Natural-hazard exposure is expected to increase dramatically. Flood-exposed housing could rise from approximately 250 million units in 2025 to 419–513 million by 2100. Earthquake-exposed housing could increase from around 495 million to 833–932 million units, while storm-exposed stock could grow from approximately 364 million to 472–547 million.

Extreme heat produces the most dramatic increase. The number of homes exposed to extreme heat could rise from around 630 million in 2025 to between 2.3 billion and 3.2 billion by 2100—an increase of 267–412 percent.

South Asia is particularly exposed. The study identifies major concentrations of future construction and flood hazards around Pakistan's Indus River basin, Bangladesh's Ganges-Brahmaputra delta and the Indo-Gangetic Plain across northern India. Sub-Saharan Africa also faces growing exposure to flooding and extreme heat alongside its massive housing expansion.

This means governments cannot separate housing policy from disaster management. Building codes, hazard mapping, zoning, drainage, flood protection and infrastructure planning need to become part of the same development strategy.

46 'Triple Burden' Countries Need Targeted Global Support

The study identifies 46 countries simultaneously facing high housing demand, significant hazard exposure and limited financial capacity for resilient construction. Thirty-seven are low- or lower-middle-income economies, while 21 are located in Sub-Saharan Africa.

The problems differ by region. African countries face exceptionally large construction volumes, South and Southeast Asian economies face high hazard exposure, while Pacific island states struggle particularly with financing. These differences mean international development partners will need targeted rather than one-size-fits-all approaches.

Concessional loans, grants and climate finance could help countries struggling with the upfront cost of resilient housing. Development institutions can also support stronger building regulations, hazard mapping, serviced land, municipal capacity and disaster-resilient infrastructure.

For the private sector, the construction boom creates opportunities for developers, engineering companies, resilient-material manufacturers, insurers, housing-finance providers and infrastructure investors. But it also creates risks. Housing constructed cheaply in hazardous locations could become increasingly difficult to finance, insure and protect.

The study's broader message is therefore about acting early. Much of the housing that will exist in 2100 has not yet been built. Governments, development partners and investors still have an opportunity to determine whether that construction creates safer and more productive cities or locks billions of people into higher disaster exposure and decades of unnecessary rebuilding costs.