Part of the coastal attraction is the appreciation of the harsh conditions
on natural and cultural elements eg. sandblasting effects of wind on glass,
erosion, rust, the impact of Toredo worms on wharf structures. These effects
have strong implications for the maintenance of structures.
- Coastal structures are generally subjected to harsh conditions,
particularly from wave attack, winds, sand movement and the corrosive
effects of salt. The coast is a popular recreation area and structures
also suffer heavy usage by the public. Vandalism is also a problem,
particularly as the majority of buildings are unoccupied for considerable
periods.
- Roof pitches should be sufficient to allow self washing and undersides
of roofs shielded from salt-laden winds, thus reducing salt build-up.
- Robust fittings and surface finishes which are capable of withstanding
high usage and are resistant to damage by vandals should be used.
- Adequate security lighting should be utilised to deter vandals whilst
also having regard to the impact of such lighting on adjacent residential
areas.
- Vegetation should be used to screen structures from salt laden winds.
- Landscape works should utilise vegetation which is resistant to
coastal exposure. Landscape design should be appropriate to the level
of maintenance envisaged. For example, in low maintenance areas, native
plants in mulched soil with crushed rock paths may be more appropriate
than a formal arrangement of plants with lawn areas.Structures should
be located away from unstable shorelines to obviate demands for erosion
protection works in the future. Where it is necessary to locate structures,
such as observation towers for lifesaving services, close to unstable
shorelines, they should be designed particularly for these unstable
conditions. Portable or demountable structures, that can be moved
when erosion threatens, are preferred.
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3.1.12
Structural Design
Structures should be designed to satisfy the engineering constraints
of the special wind and soil conditions of the coastal environment.
Wind force on buildings
is a function of windspeed, local topography, surface features of the
surrounding terrain, building form and building height. Structures in
coastal areas being located adjacent to a flat expanse of water which
offers little resistance to wind speed , are exposed to greater wind
forces than inland areas. Buildings on cliff tops and bluffs are exposed
to even greater forces due to their height above the surrounding terrain.
- Wind forces may be reduced by:
> setting structures back as far as possible from the shoreline;
> siting structures away from elevated exposed sites;
> grouping buildings;
> locating vegetation on the windward side of buildings;
> localised earth mounds in strategic locations.
- All buildings should incorporate a system of connections, such as
galvanised steel straps or framing anchors, which:
> adequately anchor the roof and walls to the footings to withstand
vertical uplift forces;
> adequately cross-brace the building to withstand horizontal uplift
forces;
> assure continuity of anchoring and bracing throughout the structure.
- Design wind forces should be calculated in accordance with appropriate
Australian Standards.
- The design of footings should take account of the soil type and
its depth and bearing capacity.
- While standard building practices can be employed to overcome the
problems associated with these soil types, particular attention should
be given to the effect of the chosen structural system on the surrounding
environment. In some areas the choice of the structural system has
a significant impact on the extent of erosion and vegetation removal
by the structure.
- New permanent structures should not be built on mobile uncompacted
sands.
- For general information concerning soils and footings consult the
appropriate authorities listed under Contacts at the back of this
document.
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3.1.13
Energy Considerations
Buildings should be sited and designed to ensure optimal thermal
performance and to utilise natural light.
- Buildings, where internal comfort is an important requirement, should
be designed to:
> maximise winter sun penetration into the building by careful orientation,
siting and use of north facing windows, whilst minimising the penetration
of summer sun with appropriate shading devices and minimal east and
west facing windows;
> minimise undesirable heat loss and gain with appropriate insulation
of the walls, floors and ceilings;
> facilitate cross ventilation by the appropriate location of openable
windows and doors; > make use of the thermal capacity and performance
of building materials to reduce internal temperature fluctuations.
- Vegetation should be used to shelter the building from summer sun
and prevailing winter winds, whilst allowing the penetration of winter
sun. This may be achieved through clever planting design for solar
control.
- Where views to the coast are to the east, west or south, windows
should be located to both take advantage of the view and allow winter
sun penetration. All such windows facing the view should be adequately
protected to prevent undesirable heat loss and gain.
- In buildings where hot water is required, consideration should be
given to the installation of a solar hot water heater.
- Ensure that adequate natural light is provided within buildings.
- Help reduce wind impact. The Victorian coast is an ideal region
for using wind generators; these should be encouraged in order to
help reduce our use of fossil fuels and to generate power. Visual
and wind buffers are needed in places such as commercial, industrial
and dry storage areas. Dense, fast growing material should be planted,
possibly together with longer living, slower growing trees.
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