The Importance of Soil Type on Your Block

The Importance of Soil Type on Your Block

What is Soil Type?

“What does soil type mean and how does it impact the build is very important and one of the most common questions we get from clients,” says Stroud Homes Toowoomba Megan Thomas.

Soil type refers to the soil range for which you intend to build your house on. If you’re building a standard slab on ground or a home on stumps, the soil type is going to significantly impact the build cost as every home is engineered to suit that particular block.

All soil types are possible to build on, it’s just important to know what type of soil your block is so you have a better understanding of the potential site costs needed if you do fall into that lower range.

How many different types are there?

There are six main soil classes:

CLASS A Acceptable Mostly sand and rock with little or no ground movement from moisture changes
CLASS S Satisfactory Slightly reactive clay sites with minimal ground movement from moisture changes
CLASS M Moderate Moderately reactive clay or silt sites, which can experience moderate ground movement from moisture changes
CLASS H1 &H2 Highly reactive Highly reactive clay sites, which can experience high ground movement from moisture changes.
CLASS E Extreme Extremely reactive sites, which can experience extreme ground movement from moisture changes most commonly found in black soil
CLASS P Problematic Sites which include soft soils, such as soft clay or silt or lose sands or sites that have had trees removed and the root systems may lead to problems

How much does the soil type affect the cost of my home?

The soil type can significantly impact the cost of getting the home out of the ground.

On a standard 250m2 home the difference between a M (Moderate) soil type and E (Extreme) can be approximately $20,000 when building on an E soil.

It is also important to note that this extra $20k doesn’t really increase the overall value of the build as the additional money is spent in the foundations and not towards home improvements.

As a result of this, it is very important when considering purchasing a block with E soil that the site costs are taken into consideration and you are aware of the extra budget that will be needed to get the home out of the ground.

How much is a soil test and how long does it take?

Soil tests tend to cost around $400 and may take up to 14 days.

If your soil test reveals a result of H, E or P you might be looking at an additional $15,000 to $20,000 in slab costs on a standard 250m2 home.

The reason for the significant increase in costs is that as you go down the range the soil becomes more reactive, meaning there needs to be more of everything.

More earthworks to allow for deeper footings, more concrete, more steel, more man hours all of which results in a significant increase in slab costs.

Often land prices will reflect these findings and you will notice that blocks with E soil tend to be $15k cheaper than those with M soil to allow for the increase in site costs.

Either way it is very important to know the soil type before purchasing land or including ‘subject to soil test’ as part of the land contract so you have an idea of what you might be looking at.

How do I find my soil type?

A correct soil reading is very important prior to the build so a professional soil test is recommended.

During a site investigation, which Stroud Homes Toowoomba provide free of charge, we can give you a range of soil type so that you have a better understanding, and if need be, can then include during your negotiations with the land agent.

As mentioned above Stroud Homes Toowoomba do provide free Site Investigations and we can organise this prior to your purchase, give you advice on the area, and arrange soil testing to be carried out.

This is a fantastic service and allows us to provide you with a more accurate quote and for you to get a better understanding of your budget and the total build cost.

Your Local Builders
Megan Thomas
Megan Thomas

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