Home demolition and recycling

This Issue This is a part of the Canterbury earthquakes feature

By - , Build 126

Recycling on a record scale is part and parcel of the demolition in Christchurch, with some homeowners knocking down their own houses.

Urgent demolition was carried out on one end of the house.
Damage to the 3-year old home after the 13 June earthquake.

Over 10,000 homes across Christchurch require total demolition due to damage caused by the 22 February earthquake. How to remove and recycle such a huge volume of material in a short space of time is a huge logistical challenge for the city.

On top of the emotional toll of losing their home, many residents have taken on the challenge of overseeing demolition themselves – taking advantage of temporary new rules around the process.

Building Act modified to allow demolition by homeowners

Requirements of the Building Act 2001 for properties in the Christchurch area have been temporarily changed through the Canterbury Earthquake Recovery Act 2011. Under the modified Building Act, a homeowner may completely demolish their house without obtaining a building consent, as long as it is free-standing and less than 3-storeys high. But before bringing in the diggers, a homeowner needs to obtain:

  • full approval from a structural engineer on the necessity and safety of demolition
  • authorisation from Christchurch City Council.

Manning a digger in Sumner

Tim Hoban of Clifton Terrace in the suburb of Sumner is getting on with demolishing his house. His 3-year-old family home was damaged beyond repair on 22 February, and he believes one-third of his immediate neighbours in the hillside suburb suffered the same fate.

Tim had emergency works to perform immediately after the 13 June aftershock, as one end of the house was threatening to fall down. He spoke to his insurers, and 2 weeks later brought in a 20-tonne digger to knock the damaged areas down. A structural engineer’s report confirmed that the entire house needed to be demolished. Although this has given Tim and his family some clear guidance, his insurance company is still waiting for a reinstatement/settlement notice from its construction partner before their claim can progress.

With a background in residential house construction, Tim decided to manage the demolition himself. ‘We built the place recently. I don’t want to see all these good materials go to waste. I want to recycle as much as we can.’ A contractor will deconstruct the house with a large digger, then a small digger will be used to sort through the recyclables such as steel, aluminium, glass, fibreglass insulation, plasterboard, concrete blocks and electrical wiring. Of the whole house, he expects only four or five small truckloads will need to be dumped, the rest can be recycled.

Transfer stations in overdrive

Environment Canterbury, Christchurch City Council and the Canterbury Earthquake Recovery Authority are helping to manage the disposal of materials. The total from all homes and buildings is estimated to be over 4 million tonnes.

Christchurch’s five transfer stations are continuing to operate in overdrive, receiving and sorting waste primarily from demolished houses and other smaller-scale residential damage. The waste will eventually be taken and sorted for recycling or disposal at the massive new Burwood Resource Recovery Park. This vast area was fast-tracked into existence in preparation for an unprecedented volume of disposed building material. Up to 1,500 trucks are expected to travel to the park each day over the next 6 months.

An innovative use of demolished clean fill and rubble has also been devised. The government has approved construction of a 10-hectare reclamation at Lyttelton Port to take 1 million tonnes of waste material from the city – recycling on a record scale.

Damage to the 3-year old home after the 13 June earthquake.
Urgent demolition was carried out on one end of the house.

Download the PDF

More articles about these topics

Articles are correct at the time of publication but may have since become outdated.

Urgent demolition was carried out on one end of the house.
Damage to the 3-year old home after the 13 June earthquake.