Clearly, not all poor urban households are clustered in underserviced slum areas; they can be located anywhere in cities and still lack one or more elements of adequate shelter. The lack of basic services in cities has various social and economic dimensions that are related to the physical structure of the environments in which people live as well as to the socio-economic conditions of families. Conversely, not all those who live in slums are poor – many people who have risen out of income poverty choose to continue living in slums for various reasons, ranging from the lack of affordable housing in better parts of the city to proximity to family, work and social networks. No single generalization fits slum neighbourhoods; they are as diverse as cities themselves. However, it is clear that expanding urban infrastructure to underserviced or informal settlements is essential for improving the lives of slum dwellers. The main reason for slum upgrading is that people have a fundamental right to live with basic dignity and in decent conditions. On another level, it is in a city’s best interest to upgrade slums and prevent the formation of new slums. If slums are allowed to deteriorate, governments can lose control of the populace and slums become areas of crime and disease that impact the whole city.
Slum upgrading benefits a city by:
Fostering inclusion. Slum upgrading addresses serious problems affecting slum residents, including illegality, exclusion, precariousness and barriers to services, credit, land, and social protection for vulnerable populations such as women and children.
Promoting economic development. Upgrading releases the vast untapped resources of slum dwellers that have skills and a huge desire to be a more productive part of the economy, but are held back by their status and marginality.
Addressing overall city issues. It deals with city issues by containing environmental degradation, improving sanitation, lowering violence and attracting investment.
Improving quality of life. It elevates the quality of life of the upgraded communities and the city as a whole, providing more citizenship, political voice, representation, improved living conditions, increased safety and security.
Providing shelter for the poor. It is the most effective way to provide shelter to the urban poor at a very large scale and at the lowest cost.
In addition, in-situ slum upgrading is:
Affordable. Slum upgrading costs less and is more effective than relocation to public housing. Developing land with basic services costs even less.
Flexible. It can be done incrementally by the city and by the residents at a pace that is technically and financially possible for both.
Viable. The poor can and are willing to pay for improved services and homes.