If you’re thinking about adding a secondary home or granny flat to your property, then Congratulations! But first you should know about the hidden costs of building some don’t tell you about.
There are a heap of Aussies rushing to build their own homes thanks to the federal government’s HomeBuilder program. It’s is a fabulous time to jump in and take advantage of this great opportunity. However, most people aren’t aware of the sneaky expenses that some builders fail to mention. In addition, the building cost of one home can vary significantly to the cost of another just due to location.
We’ve compiled a list of the most common hidden costs so you can make a more informed decision when it comes to building. Keep in mind these figures are estimates, and will vary on your property and location.
Most new builds require a site survey. This will be one of the first things your designer/builder will organise as one of your costs.
A site surveyor will accurately plot the boundaries and levels/contours of your property, site any trees, easements and existing buildings on your property. It’s all crucial information that informs the design and best place to locate your new home. Every local Council can have different rules on setbacks. These are the minimum and maximum distances your new home can be to other structures/boundaries. These restrictions will affect the size and location of your home, and should be discussed with you by your designer before you get started.
In our experience, a site survey costs around $1100.
Check out founder Mel Miller discussing all of these hidden costs of building here, or keep reading below:
Soil Test, Footings & Wind Rating
Each property has different types of soil, as well as wind ratings depending on their location. These affect how the footings of your home need to be built, how deep they need to be, and the necessary strength/bracing of the materials.
You always need a soil test, footings design and wind rating completed when building a new home. Your designer or builder should organise these, with the work to be completed by a geotechnical engineer. When building a small home, these will cost you around $800.
Flat vs Sloping Land
When it comes to building on a flat block compared to a slope you’ll likely see a significant cost difference. It’s due to the additional consulting work and building costs required to ensure your home stands the test of time.
Firstly, Councils and building certifiers normally require an engineer to complete a Landslip Report to test the soil, calculate the stability of the slope and assess the risk. This in turn informs the required footings and bracing. The report generally costs around $1200. This soil test can be used for the footings design discussed above – you won’t need two different soil tests.
Secondly, we’re finding that building on a slope typically adds $10,000 to the cost of building a small home or granny flat. Yes, you read that right! This additional cost is due to the extra lengths of steel posts and bracing required, scaffold hire, and requirement for balustrading around the deck.
This one is for those living in rural zones, not connected to town sewerage, or utilizing an onsite septic tank or similar. You will require a wastewater report from a hydraulic engineer to inform whether your existing system is large enough to cater for another home.
This report costs around $600. The capacity of a system is dependent on, and calculated from, the number of bedrooms you have in both the existing home and the new home you’re intending to build. The hydraulic engineer will inform you whether the existing septic system can be used, or whether a new or additional tank is required.
From our experience, supply/install cost of a new tank for a small home or granny flat ranges $7000-$10,000. While it’s approximately $15,000 for a new larger system that will support both homes.
If your block is in a location with a high risk of bushfires, you will need a specialist bushfire consultant to complete a hazard assessment and mitigation plan. In our experience, the plan costs $500-$700, and informs what building materials need to be used in construction.
Depending on the outcome of the report, you may need to use non-combustible or special fire-rated building materials. This includes non-combustible wall cladding and thicker glass. We’ve seen extreme cases where the same Funky Little Shack in two different areas have a difference in building cost of $30,000 due to the construction materials required.
Building Approvals (BA) vs Development Approvals (DA)
All new homes require a building approval (BA). This is done by a building certifier. The cost ($2000-$4000) is typically organised by the builder and absorbed within the builders fee. Make sure you check your builder’s fee is covering this.
Depending on your local Council requirements, you may or may not require a development approval (DA) to add a second home or granny flat to your backyard. Your Council or a local town planner can inform you of the Council restrictions and costs (if any).
We’re happy to assist you. We work with local town planners we can put you in touch with. The costs and time required for a DA is largely dependent on the local Council and town planner. In our experience, it usually costs around $3500 (combined Council and town planners fee) and takes 2-3 months for approval.
Before choosing a builder, make sure you understand all required costs so you’re not surprised or confused.
We believe it’s crucial to find the right people to help you through the process, and make sure all of the costs are as transparent as possible.
If you’d like further information on anything covered here, please contact us. We have extensive experience in these areas and can put you in touch with licensed experts.
You can contact Funky Little Shack on (07) 5679 6171 or email us at email@example.com. If you’d like to know more about your specific property book a phone call, click here today.