Reduce waste from construction and demolition

Construction and demolition waste is one of the largest waste streams in New Zealand. Locally, it forms 27.5 per cent of the estimated 700,000 tonnes of waste sent to landfill from the Waikato region each year.

This waste stream is created during the construction, renovation or demolition of residential and commercial buildings and facilities, including civil projects such as roading, bridges etc. It can be waste created from things like off-cuts, damaged materials and over-orders. The ‘big 3’ materials that form 80 per cent of waste from construction sites are timber, plasterboard and concrete.

The word demolition implies a ‘smash and bash’ operation but deconstruction is a more suitable term for businesses that appreciate the cost-saving opportunities and profit potential in recovering and reusing valuable materials. When encouraging behaviour change, particularly in larger organisations, the language used is important.

There are a range of causes for unnecessary waste finding its way to landfill. Some common ones that can be avoided through better business processes include:

• lack of site space for sorting and storing materials
• tight scheduling of construction projects
• waste prevention not being planned for at the design and build stages
• lack of buy-in or interest in waste from the team
• perceived cost of waste reduction (in time and money)
• lack of knowledge of where to send materials for recovery/reuse
• sites not being the business sites of the working teams (a lot of waste can be avoided in prefab housing where the building is undertaken in yards operated by the builders, as this allows for efficient storage of spare materials for reuse).