Pre-Purchase Due Diligence Soil Testing

You have found your dream house and want to put in an offer, but have you considered why you should test your soil as part of the pre-purchase due diligence process?

Why you should test your soil during pre-purchase due diligence

There are many different ways that New Zealand land has been contaminated:

  • It is possible that renovations or demolitions of buildings or structures were not managed properly and the soil contains contaminants, such as lead from lead-based paint or asbestos. If you are purchasing an older house, it may have been painted with lead-based paint and the lead may be in the soil from previous paint flaking or sanding.
  • Some people bury rubbish and construction waste, or just leave it lying under your house amongst the foundations. This can result in contaminants leaching into your soil.
  • Soil may have been brought in from somewhere else to flatten the land. Your property or the soil that has been brought in from elsewhere may have previously been used for an activity that resulted in soil contamination.
  • Previous owners of the house or property may have had issues with vegetables not growing, plants dying, or pets and animals getting sick for no apparent reason.
  • You might be purchasing in an area that has local pollution sources.

The due diligence is up to you. It's a good idea to test the soil before you buy, so you get an indication on whether the soil is safe, and whether further investigation, remedial actions and additional costs may be needed after you buy the property to remedy any issues.

What to test the soil for

This is completely up to you and will be determined by what you are concerned about, however the contaminants commonly found to be present in hazardous levels in residential properties include heavy metals and asbestos which can be tested for with our Common Contaminants Soil Test Kit. View the Home Buying Test Kits page to view the full suite of tests specifically for home buyers.

Check out our advice on common chemicals and contaminants and the Soil Contamination FAQ page for more information about what contaminants you may wish to test for.

Later on, once you've purchased your dream home, the DIY Nutrient Soil Test Kit can be used to test your soil for nutrients and pH levels, so you know what to add to your soil for optimal plant growth.

LIM indicates site contamination

Before purchasing a property it is always recommended that you obtain and read the LIM report (Land Information Memorandum) and property file. Your LIM report or property file may state that your property is recorded as a potentially contaminated site from previous HAIL or potentially contaminating activities. This is an indication that there is a higher than average chance that your property may be contaminated and pre-purchase due diligence sampling is definitely recommended to protect you and your family or to prevent any surprises if you intend to redevelop the site.

If you are planning to subdivide or develop the property, and Council has advised that you need to check for contaminants in the soil before they will approve your application, it's important to note that Council will require a specialist investigation. Council will not accept results from DIY sampling. Prior to purchasing a property however, DIY sampling will give you an indication of soil contamination issues prior to purchase. If you need a report that is suitable for submission to Council, contact the specialist team at EWB Consultants for more information.