Up-cycling landscapes

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Updated: July 18, 2016
Mulch

The new standard of ecological design

Words / John Gabriele for Landscape Contractor Magazine

Modern landscape designs are crisp, sleek, and functional; their intent is to engage the user with a sensual experience that personifies the modern Australian lifestyle and shapes the future and present physical environment. To achieve an aesthetic that is both long-lasting and sustainable, the landscape designer must consider the type of materials used in the landscape. Modern design often uses state of the art materials to achieve the desired outcome, which can include metals, stone, ceramics, wood, plastics and polycarbonate materials. All too often these materials are sourced new and the cost is not just one of economics; there are far greater environmental costs to consider when it comes to selecting landscape materials.

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Ashes to ashes, dust to dust = sustainable landscapes

The use of recycled products in the landscape construction industry has been gaining traction in recent years, garnering wider acceptance by a number of companies with the foresight and vision of developing sustainable, environmentally responsible enterprises. Reusing and repurposing materials has given rise to a number of alternative materials becoming more readily available for construction purposes. Bulk materials suppliers are paving the way for reducing industry reliance on products derived from natural resources.  A common criticism targeted at recycled or repurposed products is that they are inferior to the refined graded raw materials they substitute. This situation is being addressed through the collaborative research and development of recycled materials specifications by a number of government departments, external agencies and private sector suppliers. Substitute aggregate materials for use in landscape construction include recycled construction and demolition material, manufactured sand from crushed hard rock residue, blast furnace slag products, fly ash from coal fired power stations and spoil (excavated rock and soil) from major developments.

Recycled organic materials in landscapes such as composts, soil conditioners and mulches, soils for landscaping and garden use, and organic products used for playground resurfacing are readily available from suppliers Australia wide. It is advisable to ensure that such products are sourced in accordance with the relevant Australian Standards. The Recycled Organics Unit can provide detailed information on the correct use and application for a range of recycled products for the landscape industry at www.recycledorganics.com. As an independent organisation, the ROU continues to work directly with government, industry and communities for the safe and beneficial recovery and use of organic resources.

Apart from substitute materials for aggregate applications and growing media, there is a wide range of other materials that can be reused or repurposed for many landscape applications. Fencing timbers, pavers, bricks, old doors, roofing iron and steel beams, to name a few, can all be reused or repurposed to reduce construction costs and the volume of materials that would otherwise go to land fill. Such products provide a number of opportunities for contractors to utilise materials that are comparable in quality and performance to those products produced and sourced from virgin raw materials, in most instances at highly competitive or equivalent prices to raw material alternatives. Suppliers will also often have individual unique pieces that can be reused or repurposed in the landscape as garden art or to perform some function other than that for which they were originally intended.

 

From cradle to grave

One of the benefits of repurposing materials within a landscape is the historical perspective and uniqueness that such materials lend to the setting. Repurposed materials don’t necessarily need to appear rustic to achieve such results and they can also be dressed to provide a clean, fresh appearance congruent with modern landscape design principles and newly processed materials. The aim of sustainable landscape design should be to use a minimal amount of processed materials whenever practical. Consideration should also be given to the reuse of site structures or materials at the end of a project life. The aim is to work towards zero net waste over the life of a landscape project. Forward planning can reduce the volume of excavated site materials that would normally be directed to landfill.

There are recycled/second hand materials suppliers that can supply large quantities of recycled materials for construction purposes in all states and territories. These suppliers will often have some very unique materials that would normally be hard to source from suppliers of new materials. A good example of this is the supply of used hardwood railway sleepers, a very sort after item for retaining wall construction and garden steps. Old wharf timbers and bridge beams can be precision milled and, once dressed, can make exceptional timbers for use in a wide range of landscape construction applications. Sydney based company, Timber with Veins, specialises in such timbers. For a full list of suppliers, check the National Timber Product Stewardship Group website at http://www.timberstewardship.org.au.

The availability of recycled timber products that have been processed to formulate blended composite materials manufactured from a range of reclaimed wood waste (fibre) and recycled plastic materials continues to expand. The plastic component is predominantly being sourced from post-consumer recycled plastics such as HDPE shampoo bottles, water bottles and milk cartons. Composite timber products may at first appearance be an environmental alternative to forest timbers and provide a way of reducing the use of non-renewable plastics, but there are several disadvantages associated with this. The type of materials incorporated into the composites may contaminate the product with materials that reduce the long term capacity to recycle the product after its end use. A question mark is also raised when combining a synthetic material with a biodegradable material such as wood fibre, which goes against the principal of sustainability to segregate such materials. Despite this, the benefits of composite materials cannot be understated. They do provide a viable alternative to timber products and in some applications can provide superior engineering qualities over their timber counterparts.

Setting the standard

Landscapes constructed with reused or repurposed materials are not limited to smaller residential applications. Large commercial installations can utilise recycled or repurposed products just as effectively as smaller installations. Opportunity also exists for the reclamation and reuse of site materials within any size construction site with thoughtful planning prior to site excavation and demolition activities. Effective incorporation of reused, recycled or repurposed materials in landscapes requires considered planning and an integrated approach to landscape design, with collaboration between designers, suppliers and construction contractors to encourage adaptive resource management across all sectors of the landscape construction industry. The use of recycled, reused, and repurposed materials in construction is opening the path to setting a new standard for ecological landscape design.