The construction and demolition industry is one of the largest waste-producing industries in New Zealand. Construction and demolition waste may represent up to 50% of all waste generated in New Zealand, with 20% of the waste going to landfill and 80% going to cleanfill sites.
Disposing of these materials to landfill means that, as well as not being recovered for further use, they are contributing to adverse environmental effects. These include harmful chemicals leaching into soil and waterways, plus methane emissions into the air, as the waste breaks down and rots.
Types and sources
Construction and demolition waste is made up of a wide variety of materials, including concrete, plasterboard, wood, steel, brick and glass.
The sources of this waste include off-cuts, packaging, surplus materials, formwork, protection materials, damaged materials and rework.
Reduce, reuse, recover
The good news is that much of this construction and demolition waste can be reduced, reused or recovered.
However, diverting waste from the landfill or cleanfill requires careful planning for each building project. Research shows that planning for waste reduction and reuse during project planning phases is the most successful way to ensure waste is minimised throughout the project.