Low Income Housing Development and the Sustainability of Large Urban Settlements

Abstract

The growth in urban population in Third World countries has been dramatic in the last decades, motivating a very large demand for low-income housing. The offer of affordable housing units produced by the formal construction sector is not inexpensive enough to cover all the demand. This pushes many families into the informal construction of their dwellings, with very negative consequences on the quality of life. This paper shows research oriented to make legally built housing more affordable, by using the concept of progressive development. Introduction and problem statement The tendency of population to move from rural areas to urban settlements is large in Third World Countries. A Country such as Colombia saw the proportion of its urban population increase from 40% in the 1960's to more than 70% today (MesaVIS 2001). If it is considered that the population has more than doubled in that period from around 17 million to more than 40 million, the change in urban population has been from about 7 million to about 28 million or in other words, it has grown fourfold (Dane 2002). These data imply that there is a dramatic pressure on resources, particularly in medium to large cities to accommodate their growing populations. A city like Bogota, Colombia's Capital, has a current population of about 7 million, with an annual growth at present of 2.9% (Echeverry 2000). This growth implies an increased need for housing. Unfortunately this need is not adequately met for one main reason which is the lack of purchasing power of the majority of the population. The minimum wage is of about US $120 per month, and close to 50% of the population earns less than that amount per month. Meanwhile, the least expensive dwellings offered by the construction sector cost about US $7,000. Although there are policies for assisting families in need with a subsidy for home purchase, these subsidies only reach a relatively small portion of those more in need. This situation motivates an informal development of the City through the construction of dwellings outside the legal framework. In essence, this informal urban development involves the settlement of land that has not been adequately developed in terms of road access, streets, nor access to utilities in the periphery of the City. This makes the plot of land to be used for each house more affordable. The family then invests in this cheaper land and begins constructing a dwelling with a variety of low-cost materials assembled on