Approximately 26.3 per cent of the population of urban India lives in slums, according to estimates of the Ministry of Housing and Urban Poverty Alleviation. Where some people see a problem, French cement giant Lafarge sees an opportunity. "We are looking very pragmatically at our businesses and at the bigger picture of cities, which means looking at how to expand our clientele," said Alexis de Ducla, the head of Lafarge’s Affordable Housing project in India.

Over the last few years, Lafarge, the world's largest cement company, has been developing new products and initiatives to reach the 93 million Indians who live in slums. “We believe Lafarge has a responsibility to get involved in not only providing material, but also better services,” said de Ducla. “We want to look at the people who are building cities and how we can help them.”

This French multinational manufactures cement, a binding agent usually made of clay and limestone, which when mixed with water and a granular aggregate forms concrete. However, if concrete is not kept churning in a large mixer, it hardens rapidly. This makes it difficult to use in densely packed neighbourhoods like slums, which have no space to park these mixers.

"We did several studies and realised a simple fact that our materials were not reaching small sites," said de Ducla.

Lafarge’s solution was simple. Since they could not bring mixer trucks to the construction site, they developed a new form of concrete that takes longer to set. This can be transported in regular buckets on rickshaws that can negotiate bylanes more effectively. They tested this product in Mumbai's Dharavi neighbourhood in 2012 with some success.

The previous year, the company organised a four-month programme on affordable housing in Mumbai with the Institute of Urbanology, a research and consultancy initiative, and the JJ College of Architecture. During this project, they collaborated with architects and activists to develop homes that could be built by slum dwellers employing local contractors.

The housing initiatives of the Institute of Urbanlogy and Lafarge's Affordable Housing aim to give smaller contractors access to high-quality building materials and to allow slum dwellers to design homes that suit their lifestyles and occupations. This, they say, preempts the need for government-led slum rehabilitation schemes of the sort that are operating in Mumbai, a city in which 48 per cent of the population lives in slums. These rehabilitation projects only result in the development of vertical slums, they say.

"This is a work in progress," said Rahul Srivastava of the Institute of Urbanology.  "Most of our work involves constantly working with existing contractors and projects. We don't want to take ownership of the project, but help contractors to realise it."

But not all urban experts approve of Larfarge's Affordable Housing project. Though the company's tagline says that it is "building better cities", these experts contend that cities are more than mere agglomerations of homes. Sustainable cities also require public amenities and open spaces. This can only be achieved by a central planning authority, with the participation of the people of an area, they say.

"No private company can cater to the needs of the smaller people," said PK Das, an architect and housing activist. "Rehousing needs to be a massive effort led by the government in collaboration with the people of that area."

He added, "There are people living in 50 square feet huts and people living in 500 square feet huts. Will you provide both of them with the same solution and reconstruct houses that are already cramped?"