Buildings to 'sit lightly' under rebuild proposal
An area of central Christchurch is pushing to open up opportunities for the building of lightweight structures, as a less expensive and more "sensible" way to rebuild parts of the quake-ravaged city.
Peterborough Village sits within Colombo, Salisbury and Barbadoes Sts through to the Avon River.
Peterborough Village, a residential and commercial community inside the Christchurch central business district, is organising an international workshop to look into the issue in mid-February.
Spokesperson Di Lucas said there were concerns the cost of stronger and deeper foundations required under post-quake bylaws could be unaffordable for some.
She understood there were options for lightweight, cheaper but robust structures to sit lightly on the soft land as alternatives to the standard heavy structures being proposed on deep vertical piles.
"With gravels buried five to 20 metres below ground level, it is appropriate that other methods are explored."
At the workshop it was hoped case studies could be done for sites on which geotech reports were available, getting experts to look at different construction options, she said.
An example of the problem was popular restaurant Valentino's, which had consent to build, but for a two-storey tilt-slab building on the site the cost of foundations would be around $300,000.
"This is quite exorbitant for a 200sq m building."
Alternative foundation options could be less expensive, more sensible, and could be more resilient in an earthquake.
Lucas said she had spoken to structural engineers who had told her different foundation options were available, that were more practical and less expensive.
It was necessary to look at the research and testing that had been done, including that at Canterbury University.
Lucas said the community had also started talking to regulators, and more discussions were planned.
Peterborough Village wanted to be a cutting edge, innovative hub for redevelopment, with a focus on affordable resilience and sustainability, Lucas said.
The village precinct had traditionally been, and was intended to remain, half commercial and half residential, but was hugely damaged.
"Most blocks will soon have scarcely a building remaining. This provides great opportunity for innovative redevelopment."
Village chairperson Mark McEntyre said a public presentation was proposed following the workshop to demonstrate desired options. A summary of the workshop would also be published at peterboroughvillage.org.nz.