(February 2012) High density for housing informalities and environmental effects in developing cities
Housing activities may create immediate as well as long term direct and indirect influences on environment. Some informalities of housing system increases density, and thus create widespread effects on environment in the cities of developing countries. This paper is an interim outcome of the study that is targeting to determine the issues and contexts of informalities in housing due to lack of urban planning implication and violation of building construction rules in the high density cities of developing countries, as well as consequential immediate environmental effects. Moreover, this report provides some policy recommendations to reduce these sorts of informalities. Dhaka, capital city of Bangladesh has been selected as a case study city. The study has collected data from site visits to a selection of detail case study areas in Dhaka, semi-structured interviews with a selection of stakeholders of housing in the city, and secondary sources.
Density of Dhaka is one of the highest in the world that is increasing through noncompliance of planning as well as building rules by housing system. Private sector dominates on housing in Dhaka. Almost all privately owned housing areas in the city have been grown through organic way and without fulfillment of city planning. Therefore, population density is increasing through developing congested road and complex land-use mix. The residents of the city are getting less accessibility of community facilities such as open space, urban service facilities. It is increasing paved areas and reducing green areas and natural water bodies; depleting underground water and increasing surface water logging; spreading human and household wastes to the environment and degrading underground as well as surface water, air, soil in Dhaka. Infringement of building construction rules is increasing population density through reducing inter-building space and increasing floor area ratio. Consequently, it is increasing tiled surface, reducing green space and accessibility of utility services. Therefore, it is creating air circulation disturbance, temperature increase, less replenishment of underground water and creating environmental pollution.
Informalities of housing system in Dhaka are one of the major causes for environmental degradation of the city. So, for reducing environmental problems in the city it is pressing to increase conformity of Dhaka's planning and building rules by housing. Application of recently enacted Detail Area Plan (DAP) in Dhaka metropolitan area as well as Imarat Nirman Bidimala (Building Construction Rules) 2008 might reduce environmental consequences resulting from housing informalities. Furthermore, some comparable legal entities and capacity building of enforcing agencies may reduce housing informalities through city planning and building rule's accomplishment for both existing and further housing.