​About 1 billion people currently live in slum settlements – almost a third of the world’s urban population – and this could increase to 3 billion by 2050 (UN DESA, 2013). The Sustainable Development Goals (SDGs), agreed earlier this year, acknowledge the urgency of the urbanisation challenge, most clearly reflected in the inclusion of an urban-specific goal. Goal 11 aims to ‘make cities and human settlements inclusive, safe, resilient, and sustainable’, with its first target seeking to ‘ensure access for all to adequate, safe and affordable housing and basic services, and upgrade slums’ (UN, 2015).

It is, therefore, timely to review the evidence on what works in improving the living conditions in slum settlements. Our focus is on physical living conditions: that is, access to land, housing and utilities, as these are among the most salient challenges facing the urban poor. They are also core elements of UN-Habitat’s definition of a slum household.

In particular, we review the evidence of four different slum-upgrading programmes regarded in the literature as good practice: Rio de Janeiro’s Favela Bairro, the Programa Integral de Mejoramiento de Barrios Subnormales (Integrated Programme for Improvement of Slum Settlements – PRIMED) in Medellín, Colombia, Thailand’s Baan Mankong programme and a community toilets initiative in Mumbai, India. We conclude by highlighting the future challenges that governments will need to address to deal with urbanisation and the implementation of the SDG target on access to housing and slum upgrading. Ultimately, we hope this paper is a useful resource for policy-makers and donors grappling with the challenges posed by urbanisation and contributes to the wider SDG debate, particularly on how to meet target 11.1, as well as Habitat III conversations on a new urban agenda.

Paula Lucci, Tanvi Bhatkal, Amina Khan and Tom Berliner