Geography Reference
In-Depth Information
the fact that Amsterdam and Stockholm have 49 and 53 persons per ha of built-up
area respectively, compared to sprawling American cities, such as Phoenix at 10
persons/ha. Nevertheless, the growing environment movement and the recognition
of the need to reduce the massive inputs of water and energy in particular, the build-
up of wastes, congestion from car use, plus pollution from noxious emissions from
cars, especially carbon dioxide and nitrous oxide and various particulates, has led
to a revision of some older policy ideas and the generation of a series of new policy
initiatives. These seek to increase not only the degree of sustainability of urban
places, but also the attractiveness in human terms, by improving the liveability of
these renovated areas of urban places and new developments.
Perhaps the most obvious trends in the development of more sustainable urban
practices in both newly developed or urban renewal areas of cities in the developed
world are the emphases on a dozen of the most important sustainable development
principles, some of which are the familiar New Urbanism standards (Chap. 2) but
applied to renewed or renovated urban areas. These involve: increasing the density
and compactness of new urban developments; preferring brown-field over green-
field sites for future growth; ensuring the connectivity of new developments to
older areas; creating urban growth boundaries to reduce sprawl; providing greater
land use mixes in place of single function areas; conserving and re-using heritage
buildings; increasing transport sustainability by reducing car use; providing mobil-
ity alternatives, from new mass transit routes to separate bicycle paths; adding more
green space, ecological variety and sensitivity, with more permeable surfaces to
allow drainage; including carbon neutral energy generation and district-wide heat-
ing schemes; use the best conservation and waste recycling practices; create more
pedestrian-friendly spaces to make places more liveable and healthier; reducing the
risk from local natural hazards, by not building in vulnerable areas, such as flood
plains, part of the adaptation of the settlement to local physical conditions.
In all cases the objectives are to reduce energy and other resource consumption,
to re-use land, reduce pollution and the other negative externalities of resource use,
and adding ecological practices. What is particularly important is the need to reduce
car use in cities, using the policies described in Table
6.2
. All these principles are
designed to make places more liveable and healthier as well as sustainable.
6.5.1
More Effective Area Heating Solutions
One of the most important areal developments that can provide greater sustainabili-
ty in energy uses comes from the creation of District Energy Schemes. Traditionally
the heating and cooling of buildings has adopted an individual building approach,
either through fossil fuel heating systems for the building itself, typically based on
coal, peat or oil, or through connections to some grid, delivering gas or electricity,
which then either needs a power furnace to burn the fuel to convert the energy into
hot water or steam, or to directly power the heating and other appliances. These
individual systems are very inefficient, costly, and wasteful of space. In addition,
they have high installation and maintenance costs, while there are safety problems
