Abstract:
Cities have a tendency to transform through intensifying its land use in urban areas.
Bangladesh is a developing country where the expansion of the capital city Dhaka is
resulting in one of the mega cities of the world. Buildings are being built to accommodate
the increasing inflow of population within this mega city. Recent studies reveal that the
impact of urban heat island in Dhaka city is gradually increasing. Thus proper master
plan is required for sustainable development and also to improve microclimate within
urban areas. Microclimate within the streets is influenced by its morphological character,
geometric pattern, orientation, built density and available green space. In residential areas
of Dhaka, street morphology is an outcome of the neighboring built forms, usually
controlled by building construction rules. The Metropolitan Building Construction Rules
[BCR] introduced in 2006 with the application of Floor Area Ratio [FAR] with
amendments in 2008 and further in 2013. FAR rule results increased building height,
relatively smaller building footprint and potentially free ground floor resulting in an
urban street canyon with uneven canyon walls. Thus the research examines the results of
an investigation, how FAR impacts outdoor street microclimate with spatio temporal
characteristics of the ambient climatic environment. Different microclimate parameters at
pedestrian level were studied. Results from an intensive field survey were studied at
locations of different street orientations in a planned residential area of Dhaka city.
Computer based simulation results as well as observed field data were compared,
statistically analyzed and examined in terms of street orientation, aspect ratio, building
mass configuration. Comparisons of the present building regulation with the previous are
made. Possible urban design considerations are discussed to enhance urban street
microclimate for planned residential areas.
