Recent publications on the theme:
Mota, N. (2021). Incremental Housing: A Short History of an Idea. In L. Medrano, L. Recaman, & T. Avermaete (Eds.), The New Urban Condition: Criticism and Theory from Architecture and Urbanism (pp. 160-182). Routledge – Taylor & Francis Group. https://doi.org/10.4324/9781003100362-13
Baitsch, T. (2018). Incremental Urbanism, A study of incremnetal housing production and the challenge of its inclusion in contemporary planning processes in Mumbai, India. Ecole Polytechnique Fédérale de Lausanne [EPFL] School of Architecture, Civil and Environmental Engineering [ENAC] (PhD-Thesis)
Boogaard, S. (2022) Incremental and self-help housing in the Global South. How national governments are supporting an informal practice within their housing policies and programs. Utrecht University. Faculty of Geosciences. Department of Human Geography and Planning (MSc. Thesis)
Van Noorloos, F., Valenzuela, L. et al. (2020) Incremental housing as a node for intersecting flows of city-making: rethinking the housing shortage in the global South. Environment and Urbanization, Vol 32, Issue 1, April 2020.
Batra, B. (2021) Incremental Housing Development and its Implementation in India. International Journal of Scientific & Engineering Research Volume 12, Issue 11, Nov. 2021.
Wainer, L., Ndengeyingoma, B., and Murray, S. (2016) Incremental Housing, and Other Design Principles for Low-Cost Housing. International Growth Centre, London School of Economic and Political Science, code: C-38400-RWA-1.
Self-help incremental housing is important in covering the housing demand of low-income households. Although it does not deliver sufficient housing production, it is an important factor in individual home expansions and renovations. The finishing of the houses costs mostly much time, while the population growth presses more and more on the cities and urban areas. Rising land prices caused by exploding urban housing markets makes housing for the poor often unaffordable.
Many governments focus on promoting large-scale public social housing programs, where private developers realize ready-to-use subsidized projects with houses or apartments to sell to households. These solutions are often too expensive for households with low incomes, while rental homes often are missing or unaffordable. Also, no attention is given to the needs of starters on the housing market and the elderly in public housing policies. Another thing is that housing projects do not take into account incremental finishing of dwellings, and the later need to divide them into apartments.
By combining self-help – and social (public) housing, a hybrid form of housing emerges, whereby low-income households could also participate with a small core house or a starters house. Such solutions refer to organized core-house building, following the example of Ciudad Bachué, a large district of Bogotá in Colombia. This enormous pilot project was designed for incremental expansion, where the residents could play a crucial role with the incremental finishing of their homes. Main question remained: who realizes in advance the huge early investments needed in the foundations and collective building structures?
1 Pune, India, strategies by SPARC
Since 1986, SPARC has been working in India in partnership with two community-based organizations: the National Slum Dwellers Federation and Mahila Milan. Together, they are known as the Alliance. They center on individual housing in high density; which is seen in India as a slum improvement strategy.
Above: Study of informal incrementality, its impacting factors and supporting systems by SPARC (2011)
2 Bogotá, Colombia: Ciudad Bachué
One of the housing models in Ciudad Bachué: with initial provision, Planned and Unplanned expansions.
3 National Housing Authority of Thailand. By director of Department of Housing development studies. 10-11-2017 presented in Bonn, Germany.
Building growth-houses at the start, with expansion possibilities on ground floor. Also semi-detached and row houses were designed. This concept has opportinities for incremental growth on ground floor.
4 Manaus, Brazil, Multi-story incremental proposal by Portugal, Harper and Shaikley.
Building unfinished houses at start of project
Incremental housing – general information.
Incremental house building is a construction method that is used worldwide by millions of individual households. In the literature, different terms are used for the description of house construction methods that in principle have the nature of self-construction of houses by households. One can speak of ‘self-help housing’, ‘assisted self-help housing’, self-managed-housing’, and ‘incremental housing’.
Since the 1950s/1960s, self-help housing is seen as an important factor in housing production. Self-help housing is based on the power of many low-income households, which often have no other option but to create their own housing. The possession of a private plot to build on is crucial. Institutional housing in the form of social or public housing was and still is missing in many countries. As a consequence, millions of households have to use their own labor, knowledge, materials and savings for the construction of their home, or otherwise, have to search for a rental facility. In the latter case, it is usually the private market segment that provides living space. Initially, self-built homes can be very simple, and regularly consist of waste material and second-hand building materials. In later phases, the houses are improved and expanded step by step by the inhabitants. Families often make use of the help of family members and friends and also hire skilled construction workers for the execution of specialized works. However, not all households that start a building or renovation process, can or will succeed. In these cases, help from governmental or non-governmental organizations is necessary. When this is the case, one can speak of ‘assisted self-help housing’.
Since the 1970s, international institutions such as the World Bank and UN-Habitat have recognized the vital role of self-help housing in providing affordable housing solutions to (and by) the urban poor. Even today the cities in the developing world have been built for a large part on the basis of informal self-building activities. Based upon the recognition of the enormous potential and capacity of self-builders to meet the urgent housing challenges, the mentioned international institutions started developing tools for public housing policies to assist the urban poor. National and local governments also adopted the notion of ‘assisted self-help housing’, rather than completely clearing squatter settlements and by facilitating the ‘incremental’ self-build processes in such neighborhoods. Incremental house construction implies a stage-wise informal building process, realized by individual families, only if and when their financial situation allows them to take further steps in the building process. This approach has the advantage of excluding the risks of long-term financial obligations in the form of mortgages. On the other hand, it means that the entire process of finishing a self-built house may take a long time. The adoption of policies supporting incremental self-help housing reflects a major break with earlier common practices, such as the eviction of the illegal inhabitants and the demolition of their provisional shacks in squatter settlements.
Since around 2000, the term ‘incremental housing’ has been used more and more. Some researchers have found that incremental self-help housing is a phenomenon of great importance in housing production worldwide. Incremental housing can be defined as a gradual process whereby building components are appended or improved by owner-builders as funding, time, or materials become available. Incremental housing requires flexible, relatively small short-term loans that are responsive to the intermittent demands of housing. In contrast, conventional mortgage finance requires enough funding to purchase or build a complete house.
Actors in research
Latin America Housing Network (L.A.H.N.), University of Texas, Austin. Coordinator: Dr. Peter Ward.
MIT/SIGUS, Global Consortium for Incremental Housing. Coordinator: Dr. Reinhard Goethert.
The work of Architects: John Turner, Charles Correa, Balkrishna Doshi, Alejandro Aravena and others.
<Text below was derived from: http://www.spatialagency.net/database/john.turner>
John Turner is a British architect who has written extensively on housing and community organisation. He investigated the squatter settlements in Peru from 1957-1965. There, Turner studied and advised on a number of reconstruction and slum upgrading programmes which were part of a nation-wide community development initiative. During this time Peru was also a leading centre for debate on housing policy, community development and the role of self-help housing. Turner’s own theoretical stance was formed in this context and combined aspects of the work of the Peruvian urban theorists Fernando Belaúnde, Pedro Beltrán and Carlos Delgado.
Turner’s central thesis argued that housing is best provided and managed by those who are to dwell in it rather than being centrally administered by the state. In the self-building and self-management of housing and neighbourhoods, Turner asserted that the global North had much to learn from the rapidly developing cities of the global South. Through a number of empirical studies, some of which were published in a collection for Habitat International Coalition entitled Building Community, he showed clearly that neighbourhoods designed with local groups worked better since people were experts on their own situations and should be given the ‘freedom to build’, a phrase that became the title for an edited collection by Tuner. Whether this freedom was granted by the state or wrested from it through squatting was less important. Within this framework the state as well as private professionals such as architects and engineers, act as enablers, resulting in a shift in thinking that valorises experience and local know-how over technocratic and professionalised forms of knowledge.
In contrast to the ‘aided self-help’ policies of the World Bank, for which Turner is frequently credited, his vision was far more radical as he not only contended that residents should build their own houses and neighbourhoods, but that they should also have control over their finances and management. In Freedom to Build: Dweller Control of the Housing Process, which was first published in 1972, Turner sets out these views, which remain relevant today.
Charles Correa (1931-2015) was a famous architect from India. He defined modern architecture in the country, moving on from the designs that Le Corbusier made in the new city of Chandigarh and in Ahmedabad in the early years after India’s independence. Correa acted as a President of the Indian National Commission on Urbanisation and was a pioneer in the field of affordable housing, and he constantly called attention to the crucial link between affordable housing, public transport and work areas. At the beginning of the 1960s he and two colleagues were advocates of this concept and they came up with a proposal for a radical restructuring of Mumbai (then called Bombay), where the growing number of illegal settlements in the city would be addressed. The then foreseen new town was designed to accommodate 2 million people and is now known as Navi Mumbai (New Bombay). By developing land on the other side of Bombay’s port, he would convert the North-South-development development axis of Mumbai into a poly centric urbanization model around the Bay. Navi Mumbai is a large-scale new town and one of the largest in the twentieth century. It is also the location of a smaller-scale experiment: the Belapur Incremental Housing project. As an architect Correa designed only one residential tower in his own city Mumbai, but this has become an iconic building, showing his Indian approach to architecture, using local building forms based on Indian living cultures.
Source: Charles Correa Associates/ RIBA
Initially, Correa applied his ideas on housing and living to low, single houses, to incremental housing and to high-rise living. The ‘tube house’ in Ahmedabad (1962) is an early model of sustainable design for down-to-earth housing. It is a prototype of low-income housing, having a natural ventilation system and large living spaces; it was affordable as well as climate friendly. Only one tube house was built which finally was demolished in 1995. Nevertheless, the design is seen as iconic influencing the later work of Correa in the 1960 and 1970s, such as with the GHB-2 housing project (of the Gurajat Housing Board) in Ahmedabad, and designs for the PREVI (Experimental Housing Project) affordable housing project in Lima, Peru, where he showed the advantages of low-rise, high-density housing, with a cluster of incremental row-houses, with fluctuating widths, open-to-sky spaces and central double-height spaces covered by ‘wind-scoops’ for ventilation. Charles Correa’s work on housing has led to another iconic project, namely the Belapur Incremental Housing project realised in 1983 in Navi Mumbai. The project reveals the possibilities of the high-density, low-rise principle, based on a courtyard unit shared by a group of seven incremental houses. The project grew into a fully-fledged housing project to accommodate 600 households. The houses of the Belapur Housing are of one or two storeys, and were built traditionally, which fits well with the household’s life styles. The features are: high-density, incremental growth, small communities.
Images : Charles Correa Associates/ RIBA
The architect Balkrisna Doshi (1927) is another Indian architect who is dedicated to the social housing questions in India. He received the prestigious Pritzker Prize in 2018. The jury stated that “with an understanding and appreciation of the deep traditions of India’s architecture, Doshi united prefabrication and local craft and developed a vocabulary in harmony with the history, culture, local traditions and the changing times of his home country India”. During many decades Doshi created an extensive collection of educational, cultural, public administration buildings and residential projects.
Balkrishna Doshi designed the Aranya Low Cost Housing project that was realized in 1989 in Indore. The complex accommodates over 80,000 residents through a system of low cost housing with courtyards and internal pathways. The community is comprised of over 6,500 residences, amongst six sectors – each of which features a range of housing options, from modest one-room units to spacious houses, to accommodate a range of incomes. The homes were designed with extension and adaptability in mind. It won the Aga Khan award for architecture in 1995, and was praised for its integration of mixed-income groups. Balkrishna Doshi about the Aranya Low-Cost housing project: “They are not houses but homes where a happy community lives. That is what finally matters.” Furthermore he says: “It seems I should take an oath and remember it for my lifetime: to provide the lowest class with the proper dwelling.”
A new generation of architects is demonstrating the ability to connect social responsibility, economic demands, design of human habitat and the city. With his group ‘Elemental’ the Chilean architect Alejandro Aravena – is the recipient of the 2016 Pritzker Architecture Prize. He and his team have been changing several design aspects of social housing, and also public policy concerning housing. What really sets Aravena apart is his commitment to social housing. Since 2000, he and his collaborators have consistently realized works with clear social goals. Calling the company a “Do Tank,” as opposed to a think tank, they have built more than 2,500 units using imaginative, flexible and direct architectural solutions for low cost social housing. The ELEMENTAL team participates in every phase of the complex process of providing dwellings for the underserved: engaging with politicians, lawyers, researchers, residents, local authorities, and builders, in order to obtain the best possible results for the benefit of the residents and society. An understanding of the importance of the aspirations of the inhabitants and their active participation and investment in a project, as well as good design, have contributed to the creation of new opportunities for those from underprivileged backgrounds. Below: images of incremental growth in ELEMENTAL’s structures:
SPARC with and Prasanna Desai.
The architect Prasanna Desai has done research (with Society for the Promotion of Area Resource Centers) to develop an Incremental Housing Strategy that could be implemented anywhere. A team of international architects, urban planners, landscape architects and graphic designers volunteered to set up the strategy which uses the existing urban formations as starting point for development. Organic patterns that have evolved during time are preserved and existing social networks are respected. Neighbours remain neighbours, local remains local. When the architects started working the Indian government would initiate a grant of 4500 euro per family for making their homes incremental – at a national scale. The grant is now active and it can be given to any family who lives in a kaccha – an old temporary structure, not suitable for living. It is called City In-Situ Rehabilitation Scheme for Urban Poor Staying in Slums in City of Pune Under BSUP (Basic Services to the Urban Poor), and JNNURM (Jawaharlal Nehru National Urban Renewal Mission). The strategy strengthens the informal and aims to accelerate the legalization of the homes of the urban poor. Their strategy was arranged to fit the parameters of this grant. This study was done with SPARC and Mahila Milan (Women Together).
About SPARC: the Society for the Promotion of Area Resource Centers is one of the largest Indian NGOs working on housing and infrastructure issues for the urban poor. In 1984, when SPARC was formed, it began working with the most vulnerable and invisible of Mumbai’s urban poor – the pavement dwellers. SPARC’s philosophy is that if they can develop solutions that work for the poorest and most marginalized in the city, then these solutions can be scaled up to work for other groups of the urban poor across the country and internationally.
Since 1986, SPARC has been working in partnership with two community-based organizations the National Slum Dwellers Federation and Mahila Milan. Together, they are known as the Alliance. Today, the Alliance works in about 70 cities in the country and has networks in about 25 countries internationally. Sheela Patel, the Director of SPARC was awarded the Padmashree Award in 2011.
The Pune Municipal Corporation followed a participatory approach to implement an in-situ slum upgradation project under BSUP scheme of JNNURM to provide an alternative housing solution in high density slum areas of Yerwada region.
Images by Filipe Balestra and Sara Söransson of Urbanouveau.
Patricio Samper Gnekko, Ciudad Bachué
In Bogotá, Colombia, Ciudad Bachué is a high-density pilot project for social housing, that was built between 1978 and 1982. The project featured single and multi-family progressively expanded units, in total 7,124. Initially, the urban housing area Ciudad Bachué was located at the periphery of the Bogotá city centre, and later became well-connected to the city by various public transit lines. Meanwhile, the area is fully part of Bogotá’s urban fabric to the North. The project combines ten different housing types all less than 100 m2: five types are single family, five are multi-family, ranging from 1 to 5 story. All housing types were intended to be expanded progressively, except for the 4 and 5-story buildings with duplex apartments on top. Ciudad Bachué is a successful urban housing settlement, in terms of the experienced housing growth, and the evolution of community facilities and services of the settlement. Households of single-family and multi-family dwellings developed their homes within a built structure, which gave them the possibility to finish and refurbish their homes. One result of the incremental housing development is a sense of belonging, and a form of community development. The building blocks are small but incredibly dense and are mostly pedestrianised; only a few streets are wide enough to accommodate cars. The buildings are long and narrow with boxy additions stacked on top of the other onto the original structure.
Pedestrian street in ciudad Bachué. Photo by Chris Erb.