Key Trends Shaping the Future of Infrastructure.pdf
2 sustain ty-of_hs_forms_urb_models-eng
1.
2.
Overconsumption
of land.
First because
of the large
residential
plots. Second
because of
the long street
networks.
Third, this
model
“encourages”
consummative
behavior . A
widely-spread
phenomenon
is urban
degradation
due to
inhabitants
deserting poor
areas.
3.
Poor efficiency of technical
and social infrastructure. Over
expansion of the networks
causing extra investments.
Commercial and social services
are inefficient due to
insufficient clients base.
4.
Car dependence. Over expansion
of car traffic. A car on the road
“consumes” 18 times the space
“consumed” by a pedestrian, who
uses public transport. A car when
not in use (a parked car) consumes
30 to 90 times the space used by a
pedestrian – depending on the
length of the stay). Cars are the
main source of air pollutants in
towns and cities.
5. Rigid zoning
and lack of
mix of urban
uses.
The vast areas
of single-family
housing do not
allow for
integration of
any other
functions, but
dwelling. In
fact the lowdensity
residential
zones are the
best example
of „bedroom”
zones.
6.
Social
segregation.
Zoning in this
situation is so
rigid, that even
different types
of dwellings are
zoned and
cannot be
mixed. All plots
in an area
should be the
same size, all
houses should
be of the same
level. This urban
model
encapsulates
social strata.
7. An important
advantage is
the green
and well
maintained
street spaces,
Another
important
advantage is
that this type
of housing is
ecologically
efficient =
naturefriendly
construction
methods and
technologies
8.
In
principle
the use of
land in the
Traditional
Urban
Block is 4-5
times
more
efficient
than the
use in the
Lowdensity
Model.
9. This is true also
with regard to
the efficiency
of the road
and street
networks and
the efficiency
of public
transport.
No car
dependency
Alternative
transportation
options are
viable –
pedestrian,
biking, etc.
10. This is true
also with
regard to the
technical
and social
infrastructure.
This model
too is suitable
for
application
of
ecologically
efficient
construction
methods and
technologies
13. The residential densities of the Athens Charter Model are
similar to the densities of the Traditional Urban Block.
So many of the factors are similar too, but also this is
a reason to study the problems by studying the
differences.
In late 1970s and in the 1980s the Athens Charter Model
was heavily criticized because of:
over-scaling the buildings and the spaces
Too rigid zoning based on urban functions
14.
However,
though the
inhuman scale
and the rigid
zoning were,
indeed, typical
for the modern
approach for its
early period,
these are not
inherent
features of the
Athens Charter
Model. There
are hundreds of
examples of
housing estates
that are low-rise
properly scaled,
with well
defined human
street spaces.
15.
On the other
hand we have
reasons to claim
that the Athens
Charter Model
does offer great
advantages with
regard to
sustainability.
Integrating
nature and
greenery – This is
one of the two
greenest models
(the other one is
the Low-density
Model). But
public access is
provided to the
green spaces of
the Athens
Charter
17. In comparison to
the Low-density
Model, the
High-density
Low-rise Model
is characterized
with many
advantages.
Efficient use of
land. - Higher
development
densities result
in efficient
population
densities
19.
Yet the highdensity low-rise
housing forms
preserve
almost all
advantages of
low-density
housing – well
maintained
green
residential
environment,
housing forms
suitable for
environmentall
y friendly
construction
technologies
20. Extremely high
density and
intensity (FSR
usually > 3.0),
which provides
for important
advantages:
Extremely low
consumption of
land
Extremely high
density of
population –
often more than
500-600
inhabitants per
hectare
22. However, problems are faced
with regard to the
preservation of open
spaces. Minimal standards
for the distance between
buildings in Thessaloniki are
1/5 of the standards in most
English cities, in Istanbul
they are 1/10.
Lack of open spaces results in
problems like:
All urban functions that
need space are reduced as
much as possible. Green
spaces are vulnerable – in
some cases street greenery,
small parks disappear; often
missing sports and children
play-grounds.
23.
Another group of
urban functions and
systems are of critical
importance such as
street and
infrastructure
networks, any type of
communication.
These activities may
not be reduced, but
on the contrary –
they must perform at
the top of their
potential and at the
edge of technical
specifications. Their
planning,
development and
physical structure
become exclusively
difficult and risky.
24.
Other problems are
related to the
application of
„hard” and „heavy”
construction
methods and
technologies
reinforced concrete
or metal structures
that 1) it is too hard,
expensive or
impossible to adapt
or demolish, 2) these
technologies are
based on the
production of steel
and cement, that
are major polluting
agents
25.
Since this is
another urban
model with
extremely high
densities,
problems are
similar to the
problems of the
Model of the
High-rise Urban
Block. However,
it proves that all
problems
related to open
spaces are
easily solved.
26. Open spaces are
preserved and usually
maintained in best
conditions and a lot
of greenery, larger
and smaller parks,
children playgrounds
and sports facilities
are provided.
The mix of urban uses
is very high, but
always optimal
Still one problem is
the application of
“hard” and “heavy”
construction methods
and technologies
27. All advantages
related to high
densities are
present in an
extreme state:
Extremely low
consumption of
land,
Extremely short
communications,
extremely
intensive use –
which is a reason
for optimal
separation
between car
traffic and
pedestrian
connections
28.
Extremely lively cities
In fact, in many aspects this
model is a combination of
› the principles of New
Urbanism and the Smart
Growth (low
consumption of land,
efficient transportation
alternatives, mix of uses,
social integration)
› with those of the Athens
Charter (high-rise
residential building will
provide hygienic
dwelling conditions and
will free the environment
for greenery, public
activities, sports, etc.