Why are most new Australian homes built on concrete slabs?

Posted By  
30/09/2019
09:12 AM

When you decide to build a new home, one of the critical decisions you’ll have to make is what type of foundation to install. This decision is important; not only will it influence the overall design of your house; but the foundation obviously plays a central role in ensuring structural integrity. 

You have a range of choices when it comes to foundation types (including having a basement as the foundation) but we’ll focus on the two main foundation types found in Australia:

  • Stumps or stilts and;
  • a concrete slab

Unsurprisingly the humble concrete slab is the foundation of choice when building a new home in Australia. It out-competes stumps on a number of fronts. We’ll unpack this in more detail below.

Why is the concrete slab the most popular foundation type?

Affordability

First up and perhaps most importantly to budget conscious house builders (ie almost everyone!) concrete slab foundations are affordable.

Concrete slab foundation prices are generally quoted in m2 so once you know the floor plan; it’s easy to get an idea of cost. Note, prices can vary not just by contractor but also based on factors like the ease of access to the build site and the thickness of the slab required.

Stumps can cost significantly more because of the extra labour involved. The exception to this rule is if you have a very uneven block, in which case the cost of levelling (to enable a slab) could make stumps more affordable. Another cost that has to be factored in with stumps is their replacement (if they are made of timber) or repairs (in the case of sinking or moving). 

Energy efficiency

An increasingly important feature in modern Australian homes is energy efficiency. Installing a concrete slab foundation is an easy way to boost your home’s energy rating and to comply with regulatory requirements. It also just makes good energy sense, particularly in parts of Australia with significant fluctuations between day and night temperatures.

This is because a concrete slab foundation stores daytime heat and slowly releases the heat as the temperatures cool down overnight. Being in direct contact with the earth, a slab helps your whole house to maintain a stable temperature when compared to a home on stumps which is more vulnerable to temperature fluctuations.

Accessibility

With Australia’s aging population (by 2050 we are expected to have close to 1.8 million people over the age of 85) it makes sense to think about making your home accessible for future buyers and/or your future self.

Single level homes built on concrete slab foundations cater perfectly for elderly people and other people with mobility limitations. If your house is on stumps, that means stairs and to cater for people with mobility issues you’ll need to install at the very least ramps or, if your house is on stilts, even a hydraulic lift (a significant expense).

Concrete slab foundations make sense for Australian conditions. If you’re looking to build a new house, contact us today to find out about our formwork and concrete pouring services.