Ecologically Sustainable Development

Ecologically Sustainable Development, ESD There are three major aspects to consider when trying to achieve ecologically sustainable development: – environmental; – social; and – economic. So how does this fit into designing and building an Ecologically Sustainable Built Environment?

1. Environmental What we design and build should have a low impact on the environment, and if possible a positive impact.

2. Social The communities we develop and our places to live should be safe and healthy. We can achieve this through good design and by use of healthy materials.

3. Economic The decisions we make should maintain the welfare of our current population, and bear in mind future the welfare of future generations. We should use materials that are renewable rather than exhausting the worlds supply of natural resources.

Principle of ESD for buildings The Royal Architects Institute of Australia’s ESD aims are to: maintain and restore biodiversity; minimise the consumption of resources; minimise pollution of air, soil and water; and maintain health, safety and comfort of building users.

Keys to ecological construction practice Low construction cost; Easy maintenance; Healthy natural environment; Healthy living environment; and Low operation cost. Adapted from Ecological Construction Practice, H. Preisig, W. Dubach, U. Kasser & K. Viriden Zurich University of Applied Sciences

Conclusion By considering ESD when making decisions about building we can construct a built environment that is healthy for the environment and for people now and into the future.

Timber as a sustainable building material B+C Design Construct Bala Residence

Sustainable building materials The materials used to build our homes can have significant health and environmental effects When choosing materials for environmentally sustainable buildings we must consider: 1.The processes used to harvest raw material 2.Processing of material 3.Transport to site

So, what is timber? Timber is a material which can be used for building or carpentry and is derived from trees. It is organic and renewable and can be used in a wide range of applications. In order to make best use of timber in environmental buildings we must understand how timber is produced and how its natural properties effect it as a building material.

The resource The majority of Australian timber production is from managed forests. There are two broad classifications of managed forests: 1.Managed Native Forests 2.Plantations Click on image to play video >> Source: FWPRDC Education Resource Package -Construction Component

Managed native forests Managed for: Species conservation Water harvesting Timber harvesting Public education Recreation

Plantations In plantations trees are specifically planted and nurtured for timber production.

A plantation coup Most commonly plantations have only a single species is planted. However plantations can be several species.

Timber - environment 1. Growing and harvesting timber Low energy of production Carbon stored in timber away from atmospheric cycle 2. Managed Forests Plantations - single species farmed for timber Native forests managed for many uses  species conservation / biodiversity  water harvesting  timber harvesting  public education  recreation

Carbon cycle Growing Trees absorb lots of C0 2 Carbon IN Carbon OUT Large trees die by losing leaves then falling over Over long term Carbon in ~ carbon out

Environmental considerations New trees planted Managed Native Forest Plantation Growing Trees Harvesting Removes Carbon C0 2 IN C0 2 OUT Over long term Carbon removed from atmosphere > carbon released into atmosphere

Harvesting timber

Timber grows on trees! “All plant material consists of cells of various shapes and arrangements. The presence of the very complex organic substance known as lignin is an essential feature of those plants being described as woody. It bonds the various types of cell together, producing the degree of rigidity that is associated with wood, and enables woody plants to attain their large size” (Wood in Australia, 1983)

Timber is cellular!

Cellular construction of timber The cellular construction of timber effects its properties; Cells are bound together to form fibres, and have the main direction of orientation in the longitudinal direction. This makes timber a fibrous material.

Grading for forest products

Only some part of any log or tree can be used for sawn or veneer products. The remainder can be used for sheet products, paper or cardboard. Sawlogs – Approximately 30% of the tree goes to producing sawlogs Pulp Veneer

Timber is a light construction material with a high strength to weight ratio. Economic and easy to use, it is available as a structural and appearance product, and suitable for a wide range of uses. Hardwood in a drying yard

Some considerations when selecting materials! Clean materials Healthy Materials Renewable materials Natural materials Abundant materials Durable materials Resource efficient materials and material usage Reusable and recyclable material Energy Efficient material

Timber is a clean material Using Life Cycle Assessment timber can be seen to be a clean material relative to other building products like concrete and steel.

Life cycle impacts of major building materials. Source: ATHENATM Sustainable materials Institute, undated

Timber is a healthy material Timber is a natural, organic and healthy material, and its production helps clean the environment. Timber can be chemically treated to enhance performance in some ways, (appearance, durability), in most cases only a small amount of this chemical is used.

Timber is a renewable material Timber is grown and harvested in the natural environment, flows through the economy in many different applications and then returns to the natural environment at the end of its life. Managed forests ensure that timber remains in abundance as a building material.

Timber flows through the economy.

Durability issues Timber has natural durability to some hazards. This can be due to the chemicals stored in the wood structure, or in some cases it may be due to the wood structure itself. 700 year old grain store, France

Durability issues Hazard - biological or physical Natural durability of timber Treatment of Timber Design for Durability Fire

Durability Biological/ Physical Hazards: Weathering Fire Chemical Fungi Termites / borers Marine Timber: Species Natural durability of heartwood Design Detailing Minimises exposure to hazards Treatment enhances durability of sapwood Maintenance ensures protection remains functional

Timber can be durable by design Correctly specify species and treatment to match function and environment Keep timber dry Protect timber from weathering Detail connections to avoid trapped water Use corrosion resistant fasteners Isolate timber from termites - inspect regularly Maintain timber regularly - use good quality paints, stains, WRP’s Protect structural timber from fire

Timber is resource efficient All parts of a tree can be used in various applications, and care and good design can ensure greater resource efficiency when using timber.

Reusable and recyclable material There is much recycled timber available for reuse, and local council DCP’s and Green building rating tools encourage reuse. 500yr old recycled timber, France

Other recycling options Waste timber can be mulched or chipped for energy or heat recovery as biomass.

Timber is an energy efficient material Timber uses less energy to make!

Summary Timber is a renewable resource; Timber can be made more durable through good design and treatment; Timber is a low embodied energy material, with low life cycle impacts ; There are various reuse and recycle options; Timber has an important role in a sustainable built environment.