case studies / Environmental credentials of fencing in Australia
This case study estimates the life cycle environmental impacts of the construction, maintenance and utilisation of suburban fences in Australia. The fencing systems investigated include timber fences, brick and concrete block fences and steel mesh as well as Colorbond fences. The study was conducted over a sixty year period, with the fences being demolished and replaced at set intervals. The study does not take into account different functionality (eg open wire mesh versus solid fill, bush fire protection from steel sheet and brick fences).
To provide a fast and user friendly, interactive LCA case study, which allows the user to investigate the life cycle impacts of a range construction, transportation, recycling and utilisation, options.
The system analysed included the manufacture of all materials from resources in the ground, construction site activities, construction equipment, repairs/maintenance and finally, decommissioning.
The entire life cycle is considered, from resources in ground through to demolition and recycling/landfill of the structure. Landfill emissions are excluded.
Transportation mode and distance are included for each material.
Environmental impacts investigated were resource energy consumption, GGE (greenhouse gas emissions), NOx, SOx, NMVOC (non-methane volatile organic compounds), SPM (suspended particulate matter), and fresh water consumption.
Gross energy (GJ/t), or high heating value (HHV), is used. Feedstock energy is included for all materials except timber.
IPCC weighting factors (global warming potentials) are used in the calculation of greenhouse gas emissions, eg for CH4 and N2O.
Australian LCI data.The data are maintained in EMMA (Eco-model for Material and Manufacturing Assessment), BHP's LCA data system.
The study did not require any allocation. Recycled materials have displacement credits allocated based on the displacement of virgin production.
The approach and allocation rules used in the LCI data conform with ISO guidelines for LCA and attempt to simulate reality as closely as possible.