Sustainable design for a low carbon footprint
Fabiano Ximenes, NSW Department of Primary Industries
Carbon positive wood and wood products are enabling architects and designers to create buildings with low or zero (negative is possible!) carbon footprints.
7. LCA of wood products in buildingsWeighing 15-year old Radiata tree
8. Photosynthesis process To produce 0.65 g C – 1 MJ Solar power required (high quality sites) (www.butler.edu)
9. Carbon Facts Carbon makes up 50% of the tree dry weight Younger forests sequester carbon at a higher rate About 25% of the forest biomass is in roots and 20% in woody debris. Carbon is released as tree components decay Forests fires – contributor to GHG emissions
10. Carbon Facts – cont. World’s forests and soils store more than one trillion tonnes of carbon – twice as much as in the atmosphere Plantations, commercial native forests and conservation forests cover 14% of Australia Australian forests store 6.6 billion tonnes of carbon (excluding soil carbon) In 2007: plantations and managed hardwood forests removed a net 18.9 million tonnes of carbon from the atmosphere
12. Carbon Stocks in Native Vegetation Tall Open Forest Open Forest 1 2 900 Woodland 3 340 4 9 Distribution of vegetation types in Australia 5 90 Open Woodland Tonnes per hectare of carbon in above-ground biomass 45 6 Shrubland 15 Poster prepared by Kate Düttmer, 2003 Cooperative Research Centre for Greenhouse Accounting Based at State Forests of NSW Research & Development Division PO Box 100 Beecroft NSW 2119 AUSTRALIA 7 4 Grassland 0.5 Image sources: (1) Christopher Dean; (2) State Forests of NSW; (3) State Forests of NSW; (4) Kelvin Montagu; (5) Kelvin Montagu; (6) Ben Harms; (7) Silje Eikrem; (8) Stephen Roxburgh; (9) Modified from Dr J.A. Carnahan’s ‘Natural Vegetation of Australia’ map, in Australia: A Geography, ed. D.N. Jeans, Sydney University Press, 1977. 8
14. Wood products and Native Forests Native forests managed for conservation: 23 M ha Native forests managed for prodution: 9.4 M ha Production from native forests (09/10): 2.5 M m3 of saw and veneer logs In 2005: managed hardwood forests removed a net 11.9 million tonnes of carbon from the atmosphere
21. Wood products in houses Wood products in houses: from 0.2 m3/m2 in 1945 to 0.06 m3/m2 in 2008 (Kapambwe et al 2008): - Loss of markets - More open planning - Better usage of timber members Average service life of houses: 45 years
22. Wood products in landfills In 2006/07: 20.8 Mt of waste landfilled in Australia Wood waste disposal: 2 Mt / year
34. Carbon loss from forest products in landfills: field and experimental results
35. Carbon Storage in Australia's Forest Plantations, Wood Products in Service and in Landfill
36. Buildings and GHG Emissions Construction, operation, maintenance and demolition of buildings: 40% of global GHG emissions Building sector: 23% of Australia’s GHG emissions GHG emissions from buildings: double by 2050 if energy usage is not addressed Energy savings alone: 30% across the building sector by 2030 (IPCC)
40. GHG emissions and long-term storage Net GHG Footprint: - 0.2 Mt CO2-e
41. Life Cycle Assessment (LCA) “Internationally recognised scientific method of examining the total environmental burden associated with a product and its use. It embraces all the activities that go into making, transporting, using and disposing of that product.” Inputs: raw material resources (petroleum, minerals, water, timber), energy in the form of fossil fuels and electricity, etc... Outputs: Air and water emissions (CO2, CO, nitrogen oxides, hydrocarbons, chemicals), solid wastes, etc... Impact categories: Global warming, biotic resources, land use, human health, acidification, etc...
47. Assumptions Site: The house is located in a flat area in Sydney. Plumbing and electrical components are excluded When wood strip floors are used, they are sanded and sealed. Concrete and particleboard floors are carpeted and the carpets are replaced every 15 years. The house is repainted every 15 years. The house has a service life of 50 years. Decay of wood in landfills: 10%
60. Impact on Markets If major shift to “maximised wood design” in NSW Potential GHG emission savings due to substitution effect: 1 Mt CO2-e / year
61. Summary Carbon in forests and in harvested wood products: important component of the global carbon cycle Carbon in HWP in service: significant potential to increase usage Carbon in HWP: important role to play, physical storage and displacement benefits Use of wood products in house design results in lower greenhouse footprint of house construction
