What can you make with an earthquake condemned house?

When a large disaster strikes an urban area it is critical for those affected that there is an efficient and timely restoration and recovery process. One aspect of this is to remove housing that is beyond repair or on hazardous land.

The quickest (and probably cheapest) way to do this is by using heavy machinery like diggers and bulldozers to demolish the house and dump the materials at a waste disposal site. Problematically, disasters often create an influx of waste far exceeding the community’s normal waste generation. In Christchurch, New Zealand, a series of earthquakes has led to a large quantity of building debris. It is estimated that if all unprocessed waste was sent to landfill it would take 2o years to complete the demolition and disposal process.

For this reason multiple disposal sites have been needed to be established and some waste recycling is being undertaken.

House being demolished (By Fought70 (Own work) [CC BY-SA 3.0 (http://creativecommons.org/licenses/by-sa/3.0) or GFDL (http://www.gnu.org/copyleft/fdl.html)%5D, via Wikimedia Commons)

Although using heavy machinery to demolish houses is most likely the quickest cheapest option, it assumes that the materials that make up the house such as the doors, roof, and kitchen sink are no longer of any value after the decision is made to no longer inhabit the house. Given the problems with disposing of large quantities of waste this begs the question – can we reuse the ‘waste‘ after disaster?

An exhibition at Canterbury Museum aims to show that there is value to the materials from condemned houses, and that the materials that make up a house can be reused for a variety of purposes. The Whole House Reuse (WHR) project displays what can be made from materials salvaged from a house that had been condemned due to the Canterbury Earthquake sequence of 2010-11.

WHR also hopes to visually quantify the irreplaceable material being otherwise lost in the often hasty demolition process, and spark realistic discussion on the pros and cons of deconstruction and demolition.

The Whole House Reuse website states:

Over 250 people from around New Zealand and the world have invented ways of reusing these resources and the result is a huge collection of objects from a delicately carved taonga puoro by master carver Brian Flintoff, to a finely crafted backyard studio by artist Nic Moon and architectural designer Lyn Russell.

The process broadly involved three stages:

  1.  Deconstruction: Professional salvage crew deconstructed the house over 9 days (click here for a short documentary). Care had to be taken to not damage valuable materials and to inspect wood for borer and check for asbestos (some was found in the flooring)
  2.  Design: Materials were carefully cataloged and invitations for people around the country to submit designs for the project
  3.  Reuse: Participants receive materials and begin the process to reshaping the materials into new resources

Below I share some of photos I took of the exhibition (sorry phone quality!).

A dog made from electrical wiring
A chair made from a door
Appropriate 3D Richter shelf.
A table with a rather appropriate looking ‘fault’ acting as the structural bracing
The left over material that could not be reused. Often borer infected wood, rusty nails…and asbestos!

Now of course there are logistical practicalities to deal with, and the above examples might not seem like they would be scalable after a disaster, but the point is that there is indeed value with reusing materials after disasters. As a society we must decide if viewing such materials as waste is the best course of action.

Burwood Resource Recovery Park (photo from Transwaste Canterbury)

In Christchurch about a quarter of all earthquake related debris is currently being taken to Burwood Resource Recovery Park, with an aim to recycle about 50% of the material received. This represents a relatively small proportion of all earthquake debris, but even this modest amount will take until 2017 (12-16 hrs/day, 6 days/week) to filter through. This amounts to over 5 years of work from start to finish.

A mammoth job indeed.



The Story of Helike

I have always found stories of the difficulties ancient civilizations have had with geohazards and disasters interesting. The story of Helike is especially interesting in this regard. Helike was an ancient Greek city located near the Corinthian Gulf that was thought to have disappeared over night into the sea. In many respects this story is quite similar to the story of the fictional Atlantis. However, the story of Helike’s demise always appeared credible due to the fact that many of the people who wrote of the demise of Helike were contemporaries.

The story goes that a massive earthquake and tsunami devastated the city in 373BC and it subsequently sunk to the bottom of the ocean. Along with the city, 10 Spartan ships which were anchored in the harbour at the time were also said to have been pulled down beneath the water. At the time this disaster was considered to be as a result of the wrath of the God of the Sea Poseidon. It was said that for centuries after this event the ruins of the city could still be seen beneath the water. Eventually the site was silted over and consequently was lost to time and forgotten. It was considered by some to be another myth, similar to Atlantis, until its rediscovery within an ancient lagoon, near a normal fault in 2001.


Excavations at the site have found significant archaeological finds going back thousands of years to the Early Bronze Age (2500-2300 BC). Investigations by Carlos A. Alvarez-Zarikian, Steven Soter and Dora Katsonopoulou into the environmental history of the area indicates that the Early Bronze Age (EBA) is overlain by clay and sandy clay with freshwater, brackish and marine microfossils. The explanation for this has been that the EBA site was submerged in a lagoon, possibly by an earthquake on a normal fault within the area. The 373BC site is overlain by silty sands and silty clays with mostly freshwater and brackish microfossils.

A working theory is that recurring earthquakes on the fault pull the land down, submerging it beneath the water, and providing an ingredient for tsunami inundation. Rapid sedimentation occurs at this site due to the Selinous, Kerynites, and Vouraikous Rivers. This sedimentation brings the land back above sea level………in preparation for the next society to come along and develop on.

Interestingly, on the same site in 1817, an earthquake followed by a tsunami swept away much of the beach. In Vostiza (now known as Aigio) 65 people lost their lives, two thirds of the buildings were ruined and 5 villages on the plain destroyed.

This provides a very interesting perspective on how the time between significant and catastrophic events are sometimes out of sync with human time scales — including the passing down of stories. What Helike has shown is that a society finds a site which looks good for development (coastal, rivers etc.), develops on it, eventually a massive earthquake and possibly a tsunami occur, the area sinks beneath sea level, rapid sedimentation occurs bringing the area above sea level, the next society comes along and thinks this is a great place to build a city…….repeat ad infinitum.

What Helike teaches us is that relying solely on anecdotal evidence is very dangerous, but such an idea is often hard to convey to those who have lived peacefully in a region without incident for their whole lives. Adequate site investigation, including an understanding of the geological history, in the quest to analyse the suitability of the building of a site is absolutely critical to future development of cities.

Further Information

Submergence and uplift of settlements in the area of Helike, Greece, from the Early Bronze Age to late antiquity

Slip rates on the Helike Fault, Gulf of Corinth, Greece: new evidence from geoarchaeology

Recurrent Submergence and Uplift in the Area of Ancient Helike, Gulf of Corinth, Greece:Microfaunal and Archaeological Evidence


Helike Foundation

Helike: The Real Atlantis BBC documentary

Natural History Magazine article