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While New Zealand looks for ways to deal with the mountains of plastic waste that can no longer be sold to China, there is another elephant in the room – Auckland Council’s analysis shows that almost half of the waste that goes into landfill in this region is related to the construction and demolition industry.
This is partly due to the large amount of building taking place in Auckland, but also to the lack of regulation around waste minimisation. On a majority of construction and demolition sites, all the rubbish goes into a skip that is sent to landfill, rather than items being separated for reuse or recycling.
A typical house build produces around five tonnes of waste, while demolition produces around 25 tonnes.
Council’s waste planning manager, Parul Sood, says Council is working with construction businesses to develop alternatives to directing waste, especially in co-mingled skips, to landfill.
“Often companies say they don’t have the time or space for separating materials, and it’s easier to throw it all in one skip. But it’s about spending time planning, and seeing the benefits of that,” she says. “We are promoting deconstruction, rather than demolition. Demolition waste is a particularly concerning issue for many people, because they see perfectly usable materials, fixtures and fittings, being crushed and thrown out.”
Parul says another way to avoid waste, and reduce costs, on a site is to avoid over purchasing and use products efficiently to reduce the amount of offcuts.
However, as Council does not control this part of the waste stream, any reductions so far have been voluntary.
Currently Government is considering a proposal that could see the waste levy that is charged at landfills increase from $10 per tonne – Council is seeking an increase to $140 per tonne (HM November 1, 2017). Government distributes half this revenue to Councils, where is it used towards projects that minimise waste.
Parul says that making landfill the last and most expensive option will encourage reuse and recycling. “We expect over time that commercial enterprises will invest in developing new resource recovery infrastructure, for example to handle construction and demolition waste.”
Also working with the industry to help clean up its act is the NZ Green Building Council. The organisation has just over 450 members, which include developers, architects and material suppliers. It was set up 12 years ago to move the construction sector towards sustainability.
Andrea Davison, NZ Green Building Council’s technical manager of special projects, says its rating tools, which include the Green Star (for commercial buildings) and Homestar (residential) establish best practice standards for sustainability, including energy use, materials and construction waste. The standards are voluntary, but Andrea says some countries are making such standards mandatory and that can drive change.
She says she has seen more material diverted from landfill in recent years as the industry becomes more aware of the issues. “It’s possible to get 70-80 percent diversion,” she says. “A big motivation is recognition of the monetary value of the material that is being thrown away.”
She says increasing landfill fees will also help, as well as regulation. “Ideally we need a mix of voluntary targets, but with regulation backing things up. It would also help if the clients who are building commercial or residential properties asked for Green Star or Homestar standards to be applied.
“Panuku Development Auckland adopted the Homestar standard last year on the sites it controls and, as it works with large developers, it is very influential.”
The first homes to be awarded a 6 Homestar rating using a bespoke checklist developed by Panuku will soon be built in Hobsonville Point.
Plastic wrap
It puts the community’s attempts to reduce its use of plastic bags in perspective when an entire apartment block, such as Orewa’s Nautilus, is currently wrapped in around 7000 sqm of the stuff. The plastic material, called Scaf-lite, is used to protect the scaffolded areas so that work can continue in most weather conditions. Prendos NZ is project managing the work and Prendos director Philip O’Sullivan,says this material contains a netting, so it is possible to re-use it. However, once it reaches the end of it useful life it needs to be disposed of. He says in the past, tarpaulins were used, but the hold-down ropes would often break free and became a safety issue. Philip says there is a lot of waste in remediation projects on leaky buildings like the Nautilus. “The only good news for the Nautilus is that we chose a laminated aluminium panel that has avoided the cost, inconvenience and waste of possibly having to replace new panels with a fire resistant plastic core,” he says. “In the world of remediation there are so many obstacles to overcome that waste minimisation has not been an issue for us. We have to consider the affordability factors, as it the end we need to meet our client’s needs rather than our own desires.”
