Specifying efficient use of materials and considering their impact from manufacture to disposal.
Construction and demolition produce large amounts of waste.
On this page
- costs of construction wastes
- statutory requirements
- waste diversion and rating tools
- ecolabel specification for construction and demolition waste management
Construction and demolition waste makes up 40–50 percent of New Zealand’s total waste going to landfill, according to government and council documents. Each home constructed generates an average of four tonnes of waste. An Auckland study found that construction waste by weight is made up of timber (20%), plasterboard (13%), packaging (5%), metal (5%) and other (45%).
Most of this dumping of construction waste is unnecessary – it has been demonstrated that simply by sorting waste, at least half of it could be diverted from landfills and cleanfills. Large volumes of waste also increase the costs of a project and its environmental impact.
Costs of construction wastes
Environmental costs from waste disposal include:
- limited reuse of landfill sites due to potential health hazards
- energy required in transportation
- pollution to land, air and water from heavy metals and toxic chemicals
- greenhouse gas emissions
- unsustainable depletion of resources.
Economic costs from waste disposal include:
- cost of operating and maintaining landfill sites
- cost of transporting waste to landfills
- loss of financial benefit from using recycled or salvaged materials.
Social costs from waste disposal include:
- noise, dust and traffic pollution to the community
- effects of hazardous or nuisance waste to workers on a building site and to the community.
The Building Act 2004 contains sustainability principles that the Ministry of Business, Innovation and Enterprise (MBIE) and building consent authorities (BCAs) must take account of under the Act. These include:
- the efficient and sustainable use of materials
- the reduction of waste during the construction process.
The Waste Management Act 2008 was introduced to encourage waste minimisation and reduce waste disposal by applying a levy of $10 per tonne (excl. GST) on all waste sent to landfills. The levy aims to encourage people to think about how they dispose of materials, and provide an incentive to avoid waste as well as provide funding to help develop waste minimisation projects. More than $70 million has been spent on over 100 projects.
Some industry observers have said that the spending has had little impact on the volume of rubbish created or sent to landfills, however.
A report by Eunomia Consulting commissioned by a mix of councils and other bodies recommended extending the levy to different types of landfill, different rates for standard and inert waste, gradually lifting the rate and applying more monitoring and enforcement. Potential benefits would include a much larger proportion of waste recovered rather than going to landfill, and economic and employment benefits have been identified. There would be costs to implement the changes, but these would be lower than the economic benefits.
In November 2019 the government produced a consultation document Reducing waste: a more effective landfill levy. The document points out that while in other countries there is growing recovery and recycling of materials, in New Zealand, waste sent to landfills has been steadily increasing. It also says that significant quantities of waste from construction and demolition are not subject to a levy at the moment.
There is a proposal for a levy of $20 per tonne for construction and demolition fills and for an increase of the existing levy at municipal landfills to $50 or $60 per tonne.
The Ministry for the Environment estimates current levy-related waste disposal charges for construction and demolition waste of around $6.6 million each year. The levy-related cost of disposal under the proposed new levy could be between $68.9 and $75.55 million.
Waste diversion and rating tools
The Homestar rating tool for residential buildings awards points for diverting waste from landfill. At least 50% can be diverted, and often 60–70% is achieved.
(The Green Star rating scheme for commercial buildings also rewards waste diversion. The New Zealand Green Building Council reports that some commercial projects have diverted 90% of building site waste.)
Ecolabel specification for construction and demolition waste management
The New Zealand Ecolabelling Trust (which administers Environmental Choice New Zealand) has developed a specification for construction and demolition waste management to help reduce the amount of waste going to landfills. It can be downloaded from this page.
The first company to achieve the ecolabel, Christchurch company Taggart, has shown it is possible to divert 70% to almost 100% of waste from landfill, even in its work demolishing the remains of the Tui stand at Lancaster Park.
Updated: 12 July 2021