Life cycle assessment of the Waitakere NOW Home and Papakowhai Renovations

David Drysdale, Julie Sandilands.

This report provides an assessment of the environmental impacts of the Waitakere NOW Home and two Papakowhai Renovation homes using Life Cycle Assessment (LCA). All life-cycle stages from material manufacturing through to the end of life of the house are included. The inputs in the life cycles of the homes were modelled using international data, as New Zealand specific data is not available at this stage.

The operational stage of the Waitakere NOW Home was the most dominant stage in terms of global warming potential, embodied energy, and acidification potential of the life cycle, accounting for between 63-71% of the total impact. The concrete foundation of the Waitakere NOW Home accounted for the greatest proportion of the acidification potential, eutrophication potential, and global warming potential of the building. In the House 2 renovation, the main environmental impacts were from the glass wool in the insulation
materials. Glass wool is the dominant contributor to all environmental impacts in House 2, due to the large amount of insulation materials installed in relation to the other materials used. In the House 10 renovation, the main contributors to the environmental impacts are glass wool, glass, and aluminium.