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Report 4 (of 6): Cut the Noise -
The Netherlands
Introduction
New locations are needed for housing in the Netherlands
and planning policy is now focused on building in
and near towns. Although the Netherlands is renowned
as Europe's bicycle capital, the volume of motorised
traffic on Dutch roads has increased by a third in
the last ten years. Increased traffic means increased
noise. This is a problem for building companies which
by law have to construct houses to comply with strict
noise regulations.
Building at locations near roads and railways forms
an essential part of government policy and over the
next few years, the number of locations exposed to
high noise levels will increase due to planned infrastructure
works. Proposals have been made to reduce the noise
problem. Initially, noise barriers, such as embankments
and mounds, were built to counter the problem of
noise but these require major investment and are
often very unsightly constructions. Furthermore,
the enormous increase in the volume of traffic means
that the noise bunds would have to be built for ever
higher.
Bungawalls
In June 1995, in the town of Utrecht, the fourth largest
city in the Netherlands, the first bungawalls were
constructed. The project was supported by the local
authorities and received the status of "experimental
housing".
The bungawall was created to defeat the noise of the main railway in Holland
and was built at a distance of about 30 metres from the railway line. The noise
level on top of the wall is about 78 decibels and, in nearly every situation,
it is about 50 decibels on the roof terraces of the houses built behind the
bungawall.
More recently, in Utrecht, a project consisting of 78 houses has been completed.
It is situated close to one of the busiest railway lines in the country and
is in the vicinity of a motorway which has approximately 86,000 cars travelling
along it each day. Fourteen houses were incorporated into the noise bund and
it forms an effective barrier to the noise from trains and traffic.
Along the highway A2 in the village of Neerijnen in the centre of Holland,
29 bungawalls have been constructed. The housing developed alongside the bungawalls
contain rooms which are sensitive to noise, such as the kitchen, attic, bathroom
and staircase, and they are designed against the "blind" and "deaf" elevation
created by the bungawalls.
Construction of the Bungawalls
The elevation is situated about 40 metres from the highway but the residents
hardly hear the noise of traffic. An earthen wall about 10 metres high and
300 metres long was built to reduce the levels of noise from about 80 decibels
to 53 decibels (a reduction of 3 decibels reduces the noise level by half).
The wall is constructed using sand and black soil and is built at a gradient
of 1:2. It is important to use black soil (or clay) because it naturally clings
together and therefore will not slide down the slope which is at an angle of
45 degrees. The concrete wall is covered with a water resistant layer made from
the same materials usually used to construct roofing. Ten centimetres of roof
insulation is used to stop the cold coming in. The bungawall is on the west side
of the complex, so the rooms, such as the living and sleeping rooms, are built
on the east side of the house.
Noise Levels
The residents of the houses built along the bungawall have no complaint about
the noise levels while they are inside the houses because of the insulation
provided by the ten metre wall and the dike at the back of the house. However,
sometimes while the residents are outside on the patio or on the roof terrace
during intensive rail traffic the noise can be very intrusive.
The noise insulation is slightly more effective if the house is incorporated
into the bungawall but this is not absolutely necessary.
Energy Demands
The energy demand in these houses is low because the houses are full of natural
light which comes in from the roof and the sides facing away from the bungawall.
The insulation used helps to reduce the noise levels from outside and also
provides an effective means of retaining heat in the winter.
Advantages of Bungawall Housing
Combining a noise bund with housing has many advantages:
They reduce the need to build housing in ecologically sensitive areas
The noise load on existing buildings is reduced
Strips of land otherwise unsuitable for housing are used beneficially
They have attractive town planning and architectural features
Local competition for buying the houses incorporated into a noise bund has
been immense because people are keen to move into them. The prices of these
properties are now at the top end of the housing market.
For further information, please contact:
Roel Slagter,
Wilma Bouw Engineering,
PO Box 8591,
3503 RN Utrecht,
The Netherlands.
Tel: +31 30 291 0102
Fax: +31 30 296 7853
Intermediate Technology would like to thank Wilma Engineering - in particular,
Roel Slagter - for providing the original material on the noise walls.
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