The Auckland region is in the midst of a major building boom. Whilst this is good news for new homebuyers, it generates a lot of waste that usually ends up being sent to landfill.
Construction and demolition waste currently accounts for 50 per cent of Auckland’s total waste stream. Auckland Council estimates that for the year ending 30 June 2019, Auckland will produce 568,935 tonnes of construction and demolition waste. That’s the equivalent of 196 Auckland Town Halls filled to the brim with waste and stacked on top of each other.
And that number is growing. Construction and demolition waste is projected to grow at around 3 per cent per annum (current GDP is 3.8 per cent). Currently, Auckland is tracking around two years ahead of projections in terms of construction and demolition waste generation.
Diverting valuable resources from landfill to communities
It’s an issue that Auckland Council is tackling head-on with its own construction and demolition projects around the region.
The council is working to adopt a deconstruction and soft strip approach as a standard. The deconstruction methodology sees buildings carefully taken down, bit by bit, to recover materials so that they can be re-used elsewhere. This can include building fittings and fixtures, such as seating, light fittings, kitchen and bathroom sinks, as well as important building componentry and materials such as trusses, timber, corrugated iron, and steel.
“Deconstruction techniques allow us to extract and recover valuable construction materials from buildings,” says Parul Sood, Programme Director of Waste Solutions.
"It’s another way that we can support a circular economy that re-uses resources and diverts construction waste from landfill."
The opportunity at Puhoi Pioneers Memorial Park
Rodney Local Board seized the opportunity to walk the talk around minimising construction waste to landfill when they were faced with the need to demolish a dilapidated barn located on the 35.7 hectare council reserve at Puhoi Pioneers Memorial Park on Ahuroa Road in Puhoi.
“The Puhoi barn is an important historical farming landmark for the local community. So, when dealing with the difficult situation of having to remove the barn for safety reasons, we were keen to manage it in a way that was respectful to the building’s heritage.
"Being able to recover the resources from the barn and see them re-used by adopting a deconstruction approach, rather than demolition, seemed a fitting way to honour the building’s history within the Puhoi community,” says Rodney Local Board Chairperson, Beth Houlbrooke.
“Together with Auckland Council’s Community Facilities and Waste Solutions teams, we have set a target of achieving zero waste to landfill for this project.”
Building contractor, UMS NZ Limited, has sub-contracted Trow Group to undertake the demolition of the barn, as they specialise in deconstruction and salvaging of material.
Instead of a ‘wrecking ball’ approach, the team from Trow will be bringing in a four-wheel drive scissor lift so that the barn can be carefully deconstructed to recover the reusable corrugated iron and timber that make up the barn’s structure.
The deconstruction is due to get underway from 23 May 2019. Fencing and safety signage will be installed on site ahead of works starting.
Once the deconstruction is complete, a report will be published to highlight the results achieved.
Giving building materials a second lease of life
Materials recovered from the deconstruction will be sent back to Trow Group’s yard in Swanson and be redistributed to local charities and community groups in Auckland or, possibly, further afield to our Pacific Island neighbours to assist with reconstruction efforts in the islands, in the wake of recent cyclone events.