The Importance of Soil Type When Building a Home

The Importance of Soil Type When Building a Home


Considering soil type

You might not be aware, but it can increase the cost of your home by thousands of dollars. We’re talking about soil types!

Most people know exactly what they want in their new home – from what home design they want down to which mailbox to pick.

But how many people have researched the soil type of their lot and what it may mean for the build before they start planning?

Lisa Adams from Stroud Homes Brisbane East informs us about the different types of soil predominantly found in Queensland and how it may affect your new home build.


Why is soil type so important?

Soil type is important because it tells us how much the ground moves when it is wet and when it is dry.

This then tells us how much your slab will move and this information is then used when designing the slab and the footings.

As the footings and slab of the house are designed to work with the expected ground movement, if the amount of movement that the engineer expects is High or Extreme, then the footings and slab need to be beefed up to allow for this.

It can increase the cost of your home by thousands of dollars. The higher the reactivity and movement in the soil, the more engineering is required in the slab, the more Piers. These are all expensive items.

Soil type map

The letters refer to the difference in size in the soil between wet and dry, or in other words – how much the soil will shrink or swell.

Soil Type Stands For Attributes
A Acceptable Mainly wet sand – beachfront locations
S Satisfactory Occasionally encountered
M Moderate Reactive Common in sandy dry areas STROUD HOME STANDARD
H Highly Reactive Common in clay and black soil areas
E Extreme Reactive Deep black soil and clay
P Problem – or phenomenon Can be attached to ASMH or E. This means there is a phenomenon affecting the site, for example – trees, fill, existing house

Find out more about soil types on the Residential Reports: CSIRO Foundation Maintenance & Footing Performance: A Homeowner’s Guide


Can you build on any soil for the right price?

Yes you can. But if you are trying to stick to a budget, it is best to find out the soil type before the contract of the block is finalised.

You can have your land contract subject to a soil test just as you would a building & pest inspection for an existing home. Your soil type is found by drilling holes up to 3 meters deep on different sections of your block.

This allows you time to find out what you may be in for with the block before you are locked in.

At Stroud Homes Brisbane East we can organise the soil test for you. It is a $500 test and takes up to two weeks to have the results back.

We are here to help you understand the results and what is unique to your block.


Can I use a neighbouring property’s soil test results?

Unfortunately you cannot use a neighbours soil test. Soil can change from block to block.

There are a few reasons it can change so quickly. Some reasons it can change are trees or existing structures. Anything that has disturbed the land can change the soil type.

It is also very important that the company that conducts the soil test is the company that designs the slab and footings. The reason we do this is to ensure integrity in testing and design.

A soil test may also give an indication of rock under the surface. If your soil test gives us an indication of rock, we are able to plan for the possibility of hitting rock during the build.

Building Basics – Soil Type

Ask us!

The team at Stroud Homes Brisbane East can organise a free site inspection prior to your purchase, give you advice on the area, and arrange soil testing to be carried out.

Your Local Builders
Chris Goodhand
Chris Goodhand

Talk to us about soil types and building your new home