Structural Strengthening and Seismic Upgrade Work

I wish to inform you that we are soon to undertake structural strengthening and seismic upgrade work as part of our ongoing strengthening programme.

Work is expected to start November 2024 and as the work is staged, to finish in October 2025. Work will occur on various levels and areas of the Casino building.

While we would like to see you, of course it is your choice whether to visit the Casino while we undertake our seismic upgrade. The purpose of this message is to allow you to make an informed decision if to visit Christchurch Casino, prior to or during the period of work.

Recently we engaged Holmes structural engineers to undertake a seismic assessment of our building to identify, plan and implement risk mitigation measures. Holmes’ initial structural assessment indicated that our building is likely to be considered as earthquake-prone because some areas are now less than 34%NBS.

Post the February 2011 earthquake, in a detailed structural assessment the Casino was assessed as having an earthquake strength of approximately 70% NBS. The building has not changed, but the revised score reflects the new assessment standards.

Once our seismic upgrade is complete in October 2025, should the council have identified us as one, we will not be considered an earthquake-prone building.

A common misconception is that if a building is rated less than 34%NBS and/or declared earthquake-prone, the building is dangerous and should be closed immediately.

Both the Ministry of Business, Innovation and Employment (MBIE) and the New Zealand Society of Earthquake Engineers state that this is not the case, and buildings can still be occupied even when they have a low %NBS.

Our goal is to ensure minimum disruption to our guests and employees while we undertake the strengthening work. We will use some of the lessons learnt during COVID-19, to shut off areas and create zones by using screens, to minimise any impact.

Our priority is the health and safety of our employees and guests and will continue to be so.

If you have any questions do not hesitate to ask.

Brett Anderson


Christchurch Casino

Have a question you’d like to ask? Check the FAQs, or click here to submit one.


Frequently Asked Questions and Answers:

Why are you doing this now?

The Building (Earthquake-prone Buildings) Amendment Act (2016), which came into effect on 1 July 2017, is a new national system for managing earthquake-prone buildings in New Zealand.

The Act requires buildings to meet a minimum seismic rating of 34%NBS. This is considered the minimum level of earthquake rating required.

We engaged Holmes structural engineers to complete a detailed seismic assessment and provide options for seismic strengthening. The results of the assessment revealed that like many buildings around New Zealand, we need to do further seismic upgrades to our building to achieve the latest standards.

What work is being done?

Remedial work will be conducted on all levels, the carpark, the basement, back of house areas, the VIP Area, and the gaming area on level two, as well as the roof.

What does New Building Standards (NBS) mean?

NBS is an index used to characterise the expected seismic response of a building to earthquake shaking. It helps identify buildings that represent a higher seismic risk than a similar new building, built to current Building Code standards.

The seismic rating for the building (%NBS) is governed by the worst scoring element of the building identified during the seismic assessment. It is not a predictor of building failure, nor is it an assessment of safety in a particular earthquake.

Given the range of variables associated with earthquakes, no person can make categorical statements about safety, just relative degrees of risk. The %NBS metric was specifically developed to support the implementation of the earthquake-prone building legislation. This legislation seeks to quantify the seismic performance of buildings in relation to an equivalent new building and a simple metric was needed to classify buildings.

What does a low %NBS mean?

If a building is assessed as less than 34%NBS using the required assessment guidelines, it may be classified as earthquake-prone under the Building (Earthquake-prone Buildings) Amendment Act 2016, which is determined by the local Council. This means the building is more likely to sustain damage following a moderate earthquake and, in the event of an earthquake, there is a higher risk to users than there is in a new building.

In general, a low %NBS rating is no need for alarm or immediate action. The life safety risk is still very low.

Are people at greater risk by entering the Casino before the strengthening has been completed?

No. If a building is found to have a %NBS less than 34% it does not mean it should not be occupied.

To put this into context, there are thousands of public and private buildings in New Zealand that do not meet the new NBS code design requirements. A report from Te Whatu Ora found that 31 hospital buildings around the country are earthquake-prone (below 34%NBS), including 11 that house patients. They have not closed.

Risk to life from an earthquake when in a building is very low, even when that building is rated less than 34%NBS. The risk is still lower than many other common tasks we undertake on a daily basis, such as driving.

Does a seismic rating of less than 34%NBS mean that the building is earthquake-prone?

No. It is the responsibility of the territorial authority (Council) to determine whether a building is earthquake prone. A detailed seismic assessment will inform the Council in this determination. A building rating of less than 34%NBS is one of the key criteria considered by the Council when making an earthquake-prone determination.

Can you occupy an earthquake-prone building?

Yes. If a building is found to be earthquake-prone, this does not necessarily mean it should not be occupied. The Building Act provides a range of time frames for strengthening or demolition work to be completed.

What is an earthquake-prone building (EPB)?

If a building has been classified as earthquake-prone, it means the building is more likely to sustain damage following a moderate earthquake and, as a result, there could be a higher risk to employees and public safety.

Seismic ratings are essentially a risk comparator and compare a building to an equivalent new building.

The %NBS does not predict expected performance in a particular earthquake, as every earthquake is different in terms of location, depth of the epicentre and frequency of shaking. Buildings rated below the minimum standard of 34%NBS meet one of the criteria for councils to classify them as earthquake-prone buildings (EPB).

More importantly, %NBS ratings do not represent a specific assessment of safety. A building with a low rating does not mean the building is imminently dangerous and most buildings with a low %NBS continue to be occupied.

Low %NBS ratings signal that action should be taken to address the structural vulnerabilities identified. It is important to note that lower ratings reflect the presence of structural shortcomings and a lack of resilience in these systems, not the levels of shaking at which they might fail.

What risks do I face when in a building classified as earthquake-prone?

Our expert engineering advice is that the risk to people while we complete strengthening work is low. This aligns with guidance provided by MBIE and the New Zealand Society of Earthquake Engineers.

The safety of our employees and customers is our number one priority.

What are the timeframes to address the issues?

National legislation that came into effect on 1 July 2017 changed the way earthquake-prone buildings are identified and dealt with. As a result, more buildings may be considered earthquake prone. The Earthquake-prone Building Act (2016) allows many years to upgrade earthquake-prone buildings (depending on where they are located and their priority status, as determined by the territorial authority).

Prior to the change in legislation, and post the Christchurch earthquakes and that of Kaikoura, in a detailed structural assessment the Casino was assessed as having an earthquake strength of approximately 70% NBS. The building has not changed, but the revised score reflects the new assessment standards.

We expect a consent for the work to be submitted in August 2024, should see some activity on-site in November 2024 with all completed October 2025.

References: MBIE online learning modules on earthquake-prone buildings: Building Performance.