Questions and answers - Green

Repair / rebuild process can begin.

Do I need a geotechnical report to begin building in a new subdivision?

When looking to buy land in a new subdivision it is a good idea to consider seeking a written geotechnical report from the developers. Your local council will be able to advise on the need, or not, for a geotechnical report prior to applying for a building consent.

Where can I get advice on geotechnical issues?

The specialist skills required to compile a geotechnical report can be provided by engineering consultants.

Many geotechnical engineers can be found in the Yellow Pages, but make sure that you check that the engineer preparing the report is a registered Chartered Professional Engineer.

You can check the register at

If there are issues with the land in the subdivision what do I need to do?

You need to seek professional advice on what, if any, extra work needs to be carried out to ensure the land is suitable for building and the house foundations are in compliance with the requirements of the Building Code. This may incur extra costs and you need to make sure that you are aware of the full amount of these costs, and discuss and agree where those costs fall, before entering into a contract.

Can I demand a geotechnical report / investigation?

Before signing up to buy land or a building you could discuss and agree that the contract is subject to a satisfactory geotechnical report / investigation.

What is the likely cost of a geotechnical report?

Costs will vary depending on the land and the type of engineering investigations required. We recommend that you seek quotations before deciding which engineer to use. 

Is a geotechnical report really necessary?

We recommend it. We suggest you also check whether you can get any insurance without a geotechnical report. The requirement for a geotechnical report for a building site is international best practice. There are many areas in New Zealand where, because of the nature of the land, councils require home builders seek a geotechnical report before they build a house. 

Can a map be provided of where land or sections for sale are available?

CERA has been working with the Department of Building and Housing to identify land that is likely to become available in the next three to five years. That information is being analysed and we will be making information available in the months ahead.

Property developers also seem to be advertising in local papers regularly, so we would encourage you to also review that information. You are, however, advised not to enter into any contract to buy land without discussing it with your lawyer or other adviser.

What land repair and remediation may be required on green zone properties?

Properties in the green zone will have to be rebuilt to the Department of Building and Housing guidelines, which are currently being revised. If there is some land damage or liquefaction on your property, this can be dealt with through the usual EQC processes and on an individual basis. There will be some isolated exceptions in the green zone where further geotechnical assessment may be required. This will be dealt with by EQC and your private insurance company under normal insurance processes.

What Technical Category for foundation design are green zones in the Port Hills?

You can check your Technical Category in the My Property section of the CERA website.

There is also information available on the MBIE, Building and Housing Group website.

Many green zone properties on the Port Hills have a technical category (TC) for residential foundations of “n/a” which means not applicable. This is different from the TC1, TC2 and TC3 categorisations which apply to properties on the flat land, because properties in the hill areas have always required a site-specific foundation design. Also, they are not generally subject to liquefaction or lateral spread.