Environmental Engineering Reference
In-Depth Information
Consequently, it is not surprising that the 'move towards the compact city is
in the mainstream throughout Europe' [28, p. 275].
The disagreements between the compact city and dispersed city discourses
can be summarised to a large extent as a debate about two issues—which
form affords the greater energy efficiency, and which aspects of sustainable
development are more important?
The relationship between urban form and energy efficiency—especially
energy use for travel—is at the core of the sustainable urban form debate.
During recent decades, there has been a multitude of empirical studies sup-
porting the relative energy efficiency of the two urban forms. Boarnet and
Crane worked through this literature and came to a rather surprising conclu-
sion: 'Very little is known regarding how the built environment influences
travel' [13, p. 4]. Although these authors were referring to the United States,
we find the same scepticism in Europe. Williams et al. conclude that 'A great
deal still needs to be learnt about the complexity of different forms and their
impacts' [29, p. 335]. This includes the relationship between urban compact-
ness and travel patterns. A possible relationship between the built form and
long leisure-time travel by car and plane is a part of this new knowledge that
has to be learned [11].
The possible impacts of urban forms are not limited to travel behaviour.
The built form also influences social conditions, economic issues, environ-
mental quality and ecology within the city [29]. All these aspects are also
important parts of the sustainable development concept and therefore can be
used as criteria for a discussion about sustainable urban form. It should come
as no surprise that a study that has minimising energy consumption as an
overall goal could easily reach different conclusions from those of a study that
aims at using urban form to 'reduce the number of people exposed to fine par-
ticles' or to 'promote social equity'. In the end, it will be necessary to balance
these impacts because sustainable urban form is ultimately about values [30].
The dispute between the two camps has led to the development of a num-
ber of middle positions, which try to combine the best aspects of the compact
and the dispersed city discourses, while at the same time trying to avoid the
disadvantages of each. Among such alternative middle positions are the
urban village [31,32], 'New Urbanism', the sustainable urban matrix [33],
transit-oriented development [13], smart growth [34] and decentralised con-
centration [35-37], and sustainable urbanism [38]. These alternatives all try
to combine the energy efficiency gained from a compact urban form with the
broader quality-of-life aspects gained from the dispersed city. Still, whether a
specific urban form will be more energy efficient is an empirical question [11].
2.3.1.2 Density
Much of the concern with density in planning and other related fields has
been over high urban density and its assumed negative effect on the quality
of life of urban residents. The city has historically been perceived to be a place
