Physical Density and Urban Sprawl: A Case of Dhaka City - KTH

unrealistic because tall buildings need to be placed at longer distance which means the
percentage of land coverage should be less.
Rådberg has analysed the density in urban blocks in Sweden; four out of 25 has been
illustrated in figure 2.4. The values presented in the figure 2.4 are estimated ranges, which
aim to visualize the way in which different building types occupy land in relation to the FAR
values. He estimated that the FAR value for 1 storey villas range from 0.10 to 0.15 with 5-
10% land coverage whereas 8 storey tower blocks have FAR value of 0.95 with 10-15% land
coverage. These analyses can be used to analyze the physical densities of any urban block.
1 storey villas
FAR = 0.1– 0.15
Coverage 5-10%
3 storey lamella blocks
FAR = 0.55
Coverage 15 – 20%
8 storey tower block
FAR = 0.95
Coverage = 10 -15%
The analysis of densities can explore the comparison of FAR, space use and spatial qualities,
as well as dimensions of urban sprawl. Rådberg developed a systematic method to analyze
the densities of housing block for Swedish urban block (Figure 2.5). The analyses of FAR,
percentage of land coverage by building and number of storeys can be seen in figure 2.5.
Figure 2.5 shows the classification of urban blocks in the Swedish context. Rådberg (1996) is
of the view that for the classification of typologies, a typo-morphological urban analysis (as
opposed to the functional typology) of urban types should be made which means buildings
are studied in context, together with the surrounding public and private spaces. He argues that
the analysis of such object may be a group of buildings and open spaces which mean urban
block, the building lots or the street pattern.
Rådberg uses the parameters of residential density, building height and percentage of the land
covered by buildings. He suggests that the basic methodology for typological classification
should be essentially the same regardless of the country (Rådberg, 1996:386).
Figure 2.5 is showing the parameters to classify the urban types. Here the residential density
‘e’, building height or average number of storeys is ‘n’ and the percentage of land covered by
building is ‘v ’. The formula is e = v x n.
Rådberg shows that if the number of different urban blocks are registered and place each
block as a dot on the graph (according to their urban density and number of storeys), the
individual observations of blocks (dot in the diagram) tend to cluster into a larger bubble
15
19th century inner city
FAR = 1.5 – 2.2
Coverage = 40%
Figure 2.4: Density of several urban blocks in Sweden. Source: Rådberg, 1988 in
Gren, 2006: 18.