Canterbury Earthquakes Royal Commission Te Komihana Rūwhenua o Waitaha Canterbury Earthquakes Royal Commission – Te Komihana Rūwhenua o Waitaha

Those who lost relatives and friends in the 22 February earthquake can be assured that there will be a very thorough inquiry into the failure of buildings that resulted in loss of life.
Chair, Justice Mark Cooper

Interim Report


Canterbury Earthquakes Royal Commission

Interim Report

October 2011

ISBN: 978-0-477-10344-2 (paperback)
ISBN: 978-0-477-10345-9 (pdf)
ISBN: 978-0-477-10345-9 (pdf) is the official electronic format
of the Canterbury Earthquakes Royal Commission Interim Report


Letter of Transmittal

To His Excellency, Lieutenant General The Right Honourable Sir Jerry Mateparae GNZM, QSO Governor General of New Zealand.

Your Excellency

Pursuant to the Order in Council dated 11 April 2011 appointing us to be a Royal Commission of Inquiry into Building Failure caused by the Canterbury Earthquakes and to provide an Interim Report under the stated Terms of Reference no later than 11 October 2011, we now humbly submit our Interim Report for Your Excellency’s consideration.

We have the honour to be

Your Excellency's most obedient servants

Hon Justice Mark Cooper (Chairperson)

Sir Ronald Carter

Adjunct Associate Professor Richard Fenwick

Dated at Wellington this 10th day of October 2011


The Royal Commission of Inquiry has been at work in Christchurch since 4 May 2011.

In the period since then we have worked out our approach to the Inquiry, and begun implementing it.

Much of our work has been behind the scenes. It has involved gathering facts from people and organisations, collecting engineering reports and other information about the performance of buildings in the earthquakes, and specifying work and reports that the Royal Commission considers it needs to cover the broad ground mapped out in the Terms of Reference. Many of these reports have been received, published on the Royal Commission’s website and are being analysed. Peer reviews of the reports, requested from eminent overseas experts, are also coming in.

The Royal Commission called for expressions of interest in the Inquiry, to be lodged by 22 July 2011. Public hearings will begin on 17 October 2011. In the following weeks and into the New Year the Royal Commission will hear both from those who have filed expressions of interest and from those whom we have specifically sought out as likely to have information or opinions that will assist the work of the Inquiry.

The Terms of Reference specify that the Royal Commission must provide an Interim Report by 11 October 2011. That date comes with the Inquiry well underway, but at a time when it has not been possible to embark on the public hearings. Nor has the Royal Commission had time to consider the results of the separate investigation being carried out by the Department of Building and Housing into the failures of the PGC, Forsyth Barr and Hotel Grand Chancellor buildings, which have only recently been published, while the Department’s investigation of the failure of the CTV building is yet to be concluded.

Our Terms of Reference specify that this Interim Report should contain recommendations that inform early decision-making on rebuilding and repair work that forms part of the recovery from the Canterbury earthquakes. They also envisage interim recommendations that relate to any measures necessary or desirable to prevent or minimise building failures due to earthquakes in New Zealand.

The timing has, of necessity, meant that the Royal Commission has not been able to produce a lengthy list of recommendations. However, this Report does make some recommendations which reflect our view that urgent action is required in respect of some aspects of current building design practice, both in Christchurch and elsewhere, to make some buildings’ elements (particularly stairs and floors in multi-storey buildings) more resilient. The Royal Commission is also of the view that immediate action is necessary to strengthen parts of unreinforced masonry buildings that could fail, causing injury or loss of life, in earthquakes that are less severe than the Canterbury earthquakes were. We have made recommendations accordingly.

Other issues must await the Final Report, including the lessons to be learned from the catastrophic failures of the CTV and PGC buildings.

The Royal Commission is aware that, for all those who lost family and friends in those buildings, and for those bereaved as a result of the other building failures on 22 February 2011, it is vitally important that the explanation for the building failures be provided as soon as possible. We ask for their understanding that it was not possible to provide that explanation in this Interim Report.

Justice Mark Cooper



On 4 September 2010, at 4:35am, an earthquake of magnitude 7.1 struck Christchurch and the surrounding Canterbury region. It has been followed by three major earthquake events occurring on Boxing Day 2010, 22 February 2011 and 13 June 2011. The sequence of earthquakes includes the many aftershocks that have occurred since 4 September 2010 and, at the time of writing, are ongoing.

The earthquakes have had a major impact on Christchurch – its people, their physical and psychological well-being, the infrastructure, the economy, residential housing and the buildings in the central business district (CBD).

The Royal Commission has been advised by GNS Science1 (GNS) that by world standards the earthquake of 4 September 2010 was a major earthquake. Yet there were no fatalities and comparatively few injuries, probably attributable to the early morning time at which the event occurred. The earthquake nevertheless caused damage to ‘unreinforced masonry buildings’ (URM), and to old stone buildings of heritage value. In the eastern suburbs and Kaiapoi there was significant liquefaction, with silt oozing to the surface and lateral spreading of the land, causing damage to houses and infrastructure. The earthquake had its origin on a fault that was previously not known to exist. It left a well-defined surface rupture that is now known as the Greendale fault. According to GNS, this was a rare event, occurring in an area where previous seismic activity has been low in New Zealand terms.

Following numerous aftershocks, there was a further significant event on 26 December 2010. The earthquake on that day had a magnitude of 4.7, lower than other events that have occurred in the sequence of earthquake events. But it was located less than two kilometres from the central city, and so caused further damage to buildings. Two other earthquakes also occurred with magnitudes respectively of 4.6 and 4.4, on that day.

By far the most serious event, in terms of the damage to buildings and the resultant loss of life, was the earthquake that occurred at 12:51pm on 22 February 2011. Its magnitude was 6.2, but it had an epicentre six kilometres southeast of the city centre. It resulted in the deaths of 182 people, and significant numbers suffered injuries, many of them very serious. Much of the loss of life was the result of the catastrophic collapse of two multi-storey office buildings, the Canterbury Television (CTV) and Pyne Gould Corporation (PGC) buildings where, respectively, 115 and 18 people died. Elsewhere, both within the area bounded by the four avenues and outside but near that area, 42 other people died as the result of building failures. There were seven other deaths resulting from the earthquake, but arising from causes not related to building failures and so outside the Royal Commission’s Terms of Reference. They include those attributable to rock falls.

The scale of the tragedy in human terms has touched numerous lives not only in Christchurch but throughout New Zealand, and indeed around the world. Of those who died in the earthquake, 77 were foreign nationals. They came to Christchurch from Australia, Japan, China, South Korea, the Philippines, Thailand, Malaysia, Taiwan, Israel, Canada, the United States, Turkey, Ireland, the United Kingdom and France.

The tragic events of 22 February 2011 resulted in the establishment of the Royal Commission of Inquiry into Building Failure Caused by the Canterbury Earthquakes (the Royal Commission). Under the Terms of Reference, the Royal Commission is required to provide an Interim Report by 11 October 2011 and a Final Report no later than 11 April 2012.

This is the Royal Commission’s Interim Report.


Purpose of the Interim Report

The Royal Commission’s Terms of Reference are set out in Appendix 1. They contain two separate references to the Interim Report. The first states that the Royal Commission is to make both interim and final recommendations upon or for—

(a) any measures necessary or desirable to prevent or minimise the failure of buildings in New Zealand due to earthquakes likely to occur during the lifetime of those buildings; and

(b) the cost of those measures; and

(c) the adequacy of legal and best-practice requirements for building design, construction and maintenance insofar as those requirements apply to managing the risks of building failure caused by earthquakes.

The second reference requires the Interim Report to contain “interim recommendations that inform early decision-making on rebuilding and repair work that forms part of the recovery from the Canterbury earthquakes”.

The Royal Commission understands these provisions as requiring it to consider, at the Interim Report stage, not only measures that should have effect in Christchurch as it rebuilds following the earthquakes, but also in New Zealand as a whole.

This report provides recommendations and conclusions, where possible, on issues about which the Royal Commission has formed preliminary or final views. There are few in the latter category, as could be anticipated given that the Inquiry is only part-way through, and there has been no opportunity to hear what interested parties might wish to contribute in hearings yet to take place. 

Structure of Interim Report

The Interim Report is presented in four sections:

1. Summary of Recommendations (page 6);

2. Inquiry Process and Progress (page 11);

3. Inquiry Issues and Recommendations (page 23);

4. Appendices (page 50):

1.  Royal Commission’s Terms of Reference

2.  List of Advisors to the Royal Commission

3.  Concepts Used in Seismic Design

4. Glossary. 

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