This paper is based on a literature review and an evaluation of practices that have been I place with respect to low cost building materials and technologies so as to lower costs and hence make the buildings, especially housing for the majority urban poor who have meager resources and hence cannot afford conventionally built houses. The paper utilized both secondary data from the literature, and an empirical study of pilot projects that have been constructed in different regions of Kenya by utilizing traditional architectural research techniques akin to observational techniques in the social sciences, augmented by open-ended interviews and discussions with the different actors in the advocacy and use of low cost materials and technologies in building. This study found out that topmost of the constraints that hinder wider application and universalism for the alternative materials and technologies is largely due to both lack of standards and specifications, and also information by the general populace about them. Otherwise I general, the alternative materials and their technologies are quite economical, durable, sanitary and safe in construction as attested to my findings from the case studies for this paper. Over the last five, or so decades, developing countries in particular have experienced phenomenal growth of urban areas partly due to policies that have tended to favours urbanization as an engine of rapid development (Duranton: 2008). However, this trend has had worsening urban housing conditions and in particular, the sprawl of informal settlements and slums is the single-most manifestation of the urbanization phenomenon that has brought about human misery, poverty, insecurity and failures of national policies, administration and economies (UN Habitat: 2008). Proliferation of these settlements is a combination of rapid rural-urban migration, internal and external displaced persons due to conflicts and wars, high birth rates, increased poverty and marginalization, soaring land prices such that the urban poor cannot afford, weak urban planning.