Global Housing: Slums, Informal Settlements and Affordability

SDG target 11.1 aims to ensure access for all to adequate, safe and affordable housing and basic services and to upgrade slums by 2030. It is tracked by indicator 11.1.1, the proportion of the urban population living in slums, informal settlements or inadequate housing, with UN-Habitat as custodian [2][5].

In 2024 about 1.16 billion urban residents, almost one in four, lived in slums or informal settlements without access to safe water, sanitation, secure housing or adequate living space [1]. UN data put the share at 24.8% of urban residents in 2024 [4].

The slum share of the urban population was 25% in 2015, fell to 24.2% in 2020 and rose to 24.8% in 2022 [2]. The total slum population was 1.12 billion in 2022, 130 million more than in 2015, ending a consistent decline from 2000 to 2020 [2]. That implies roughly 0.99 billion slum dwellers in 2015 (FREEE.REPORT calculation) [2].

The number reached about 1.16 billion in 2024 [1]. Even where the share has dipped, urban population growth keeps pushing the total up [1].

Over 85% of all slum dwellers in 2022 lived in three regions: Eastern and South-Eastern Asia (362 million), Central and Southern Asia (334 million) and sub-Saharan Africa (265 million) [2].

The 2020-2022 setback was concentrated in Eastern and South-Eastern Asia, where the slum share rose from 21.7% to 24.8%, and sub-Saharan Africa, where it rose from 50.2% to 53.6% [2]. Sub-Saharan Africa is expected to see the largest proportional increase, with an extra 360 million slum dwellers by 2030 if current trends persist [2].

The UN's 2025 SDG report says housing affordability has reached crisis levels, affecting between 1.6 billion and 3 billion people worldwide [3]. Data from 124 countries show the global average housing cost burden - the share of household income spent on rent or mortgage payments and utilities - was 31.0% in 2023 [3].

Without urgent, coordinated action, the UN projects the global slum population could exceed 1.2 billion by 2030 [1]. The UN names barriers to affordable housing, insecure land tenure and limited urban planning capacity as the main structural obstacles [1].

Figures come from the UN Statistics Division's Sustainable Development Goals Reports for 2024, 2025 and 2026, the UN data portal for SDG indicators and the UN DESA Goal 11 page [1][2][3][4][5]. Slum estimates are modelled by UN-Habitat from household surveys and censuses and refer to urban populations only. The 2015 slum population (about 0.99 billion) is a FREEE.REPORT calculation: 1.12 billion in 2022 minus the reported 130 million increase. The 2030 figure is a UN projection, not an observed value.