Revised guidelines for repairing and rebuilding houses affected by the Canterbury earthquakes

The Ministry of Business, Innovation and Employment (MBIE, and, in part,  formerly the Department of Building and Housing) has updated guidance on repairing and rebuilding houses affected by the Canterbury earthquakes. The guidance covers foundation repairs and rebuilds in the various Canterbury green zone categories. The methods or solutions proposed in the document are not mandatory. The media release is here.

A major irritation, carried over from similar previous material, is the specification that the key audience is: engineers, designers, builders, Building Consent Authorities (BCAs), insurance companies. Once again, those with the most at stake are talked over rather than with.

In the Foreword (p.4) MBIE state that “ (the Guide) gives robust and well-balanced engineering solutions that will reduce the risk of injury to people and damage to homes in future earthquakes.” Fine – so how about making the intended beneficiaries part of the key audience? Why not keep them fully informed about what is an essential health, safety, wellbeing, and family investment matter? For the last two years the credibility of the above-mentioned key audience has been very low based on a widespread recognition of their low levels of competence. More transparency is needed so approaches and competencies can be better monitored.

If the MBIE genuinely feel that the document is not suitable for home owners then how about some effort to produce a parallel and substantive version making clear what is thought to be technically challenging?

The basics and basis of the changes are:

MBIE guidance: Repairing and rebuilding houses affected by the Canterbury earthquakes

In January 2013 the Ministry updated and republished guidance on house repairs and reconstruction in Canterbury.

The updated guidance reflects new scientific and geotechnical information and knowledge about the impact of earthquakes and the effects of liquefaction on residential dwellings.

It brings together three separate documents into a single document, colour-coded for easy navigation.

Updates in this version include:

  • appropriate geotechnical investigations
  • repairs to foundations and new foundations in TC1 and TC2
  • assessments of retaining walls for hillside properties
  • chimney repairs
  • repairs to house superstructures, pole frame houses and masonry walls
  • information about repairing and rebuilding foundations in TC3
  • guidelines for the geotechnical investigation and assessment of subdivisions in the Canterbury region.

The meaning of Technical Categories

Building & Housing (formerly the Department of Building & Housing) have released information on what the technical categories mean. This will be mainly of interest to those in Green zones, many of whom are struggling to understand what is going on. The link here takes you to a video and transcript with explanations on the categories. .

Southern Response – temporary repairs to houses

Southern Response have updated their website with information for those awaiting either rebuilds or repairs, and wishing to stay in their existing damaged property until then. The following is from the new section (here) :

What should you do if you need temporary repairs to your house?

We are sometimes asked to do temporary repairs to a customer’s home to make it more habitable and comfortable, before the main repairs are done, or before the house is rebuilt.  This might cover things like cladding or roofing, insulation, drainage or removal of liquefaction. If you believe your property needs temporary repairs for you to be able to remain living there, please contact us to talk about your situation.  We look at each request individually, taking into account all circumstances. We need to ensure our customers live in weathertight, secure homes that they are able to heat, and that their home is structurally safe to live in.  Temporary Repairs for Rebuilds If your home needs repairs so that you are able to remain living there until it is rebuilt, the cost of doing these repairs will most commonly come from your temporary accommodation allowance or, if you choose, or from the funds allocated to rebuild your house.  We will ask you to enter an agreement that the cost of the repairs will:

  • Come from any temporary accommodation allowance you may have through your policy with us, or
  • Be repaid to us by you if you choose to take a cash settlement rather than build with us, or
  • Come from the rebuilding funds if you choose to rebuild with us, or
  • Be funded by an advance from us, which will be repaid by you before your rebuild begins.

We also need the agreement of any financially interested party (bank etc) before we can proceed with a temporary repair agreement. Customers will need to have a clear understanding that if they proceed down this proposed temporary repair path using rebuild funds, they will have less settlement funds from Southern Response to finally repair or rebuild their home. Temporary Repairs for Repairable Houses If you need repairs done so that you can stay in your house until the main repairs are done we will see if we can bring forward some of those repairs to enable you to remain living there.  We will only pay for repairs to any part of your house to be done once.  If temporary repairs would have to be redone as part of the main repairs, we are likely to choose to cash settle your entire claim so that you can manage the repairs in your own timeframe.


CERA release of ground land date used for the zoning reviews.

CERA have released the data and maps used as part of the zoning review. They are very detailed and much grief might have been avoided had they been released as part of the review process. From the CERA website (here).

These documents contain all the area-wide geotechnical information which was considered by CERA as part of the process for making flat-land zoning decisions, and the subsequent zoning review. These reports include mapping of ground cracking, liquefaction and lateral spreading observations, LiDAR ground elevation and vertical ground movements. At the end of the each report is a summary of the area-wide geotechnical considerations and map citations. They are written in plain English where possible, but do contain technical information where this is necessary to accurately explain the nature of investigations, and the effects of the earthquakes on the land.

The documents are available in PDF format and cover these areas (click on the area name to get the document) :

Lifting earthquake-affected buildings in Christchurch

The Department of Labour has produced a fact sheet “to improve awareness of the hazards involved in lifting buildings in Christchurch.  It also provides industry recommendations for controlling these hazards.” The fact sheet is a good way to become familiar with accepted practices to be used in Canterbury, and to check your insurance companies detailed costings to ensure nothing has been missed or understated. An important note for those in TC2 and TC3 – the factsheet says:

There are a number of methods that house movers use to support buildings once they have been lifted.  The method they use depends on a range of factors including: size of building, topography of site, exposure to wind, and complexity of the new foundations. Note: lifting and stabilising work conducted on TC2 and TC3 land should be informed by geological advice.  Contact the engineer responsible for the foundation repair/rebuild proposals to see if there are any particular concerns that need to be accounted for.

Has your insurance company factored this in? The fact sheet is here, along with links to other material on lifting buildings. .