Our delight for DIY, and New Zealand’s current construction boom, are putting landfills under serious pressure.
While building activity is particularly strong in Christchurch and Auckland at the moment, we need to get better at diverting waste from landfills around the country. After all, we’re only a small country with a limited amount of land – and the methane and leachates emitted from waste take a toll on our precious environment.
The construction and demolition (C&D) industry is one of the largest waste-producing industries in New Zealand. C&D waste represents up to 50% of all waste generated in New Zealand, according to the Building Research Association of New Zealand. Cutting down on construction waste can save you money during a build or renovation, while reducing pressure on our landfills.
You don't need to be a builder or have any technical knowledge to make a difference – all it takes is a bit of planning, and talking to other people on your project so they know what's going on. So how does it work?
What to do with…
Many building materials can be reused or recycled, diverting them from landfill. Here are a few examples:
- Concrete: Companies such as Firth re-use concrete from demolished buildings to create new construction material – such as aggregate, a rocky material used in building and roading.
- Steel: 85-95 per cent of steel used in construction is already recycled. Scrap metal can be re-melted again and again, and used for many purposes.
- Wood: Demolition companies around the country will buy timber in good condition, everything from posts to old wooden doors. (They also sell these materials to the public, if you’re looking for reused materials for a project.) Treated timber can be used for outdoor landscaping, such as decks and retainers for garden beds. All kinds of timber, even treated, is used as a fuel source at places such as Golden Bay Cement, which won an EECA Renewable Energy Award in 2012.
- Particle board: This can be reused, or recycled into gypsum and paper.
- Bricks and windows: Head to your local demolition company. They’ll likely buy these products, and on-sell them to other keen renovators and builders. Aluminium windows can be reused or recycled.
- Glass: If window glass isn’t in good condition, it can be recycled.
- Paint: Resene and Dulux offer takeback schemes, where you can drop off unused paint and it’s reused or donated to community groups.
- Insulation: If insulation is old but still in good condition, some companies take it and re-sell it.
Where do I begin?
Ask your builder to set up a REBRI construction waste plan. This will reduce the amount of construction waste sent to landfill, as often materials such as bricks, wood and windows can be recycled. There’s plenty of advice, guidelines and forms available. http://www.branz.co.nz/REBRI
You can ask contractors to sort waste on-site, or arrange for a waste management company (such as Waste Management and Green Gorilla) to pick up the material and do waste sorting at their own facility. Junk Run also offers a pick-up service.
If you’re demolishing or deconstructing a house, talk to a recycling operator first so you know which materials to save and how best to do so. Freecycle is also a great way of passing on building materials to others: it’s common to see doors, windows, framing and timber offered up for free on this nationwide website.
Our rating tools for residential and commercial buildings, Homestar and Green Star, both award points to projects that divert a certain level of waste from landfill. At least 50 per cent, and often 60-70 per cent, diversion is common in Homestar; 70 per cent is easily achievable in Green Star, and some projects reach an impressive 90 per cent.
Go on – our landfills will love you for it!
* Want to learn more? We've made two videos about reducing residential construction waste.