Duplexes are just as easy to build as a traditional home; however, the planning process can be quite involved. Not only will you need to consider whether or not you want to subdivide your land, but you’ll also need to prepare for the costs associated with a duplex build—both financially and schedule-wise.
Many factors, such as legal processes, location, and build costs, can impact your build cost. This is offset by the high value of a duplex build due to potential rental income and fall-back equity from the second property.
Firstly, however, you’ll need to figure out if you can build a duplex on your land.
Can I build a duplex on my land?
The main thing that will impact your ability to build a duplex is property size. A standard rule for duplex blocks is that they should be at least 600 sqm; however, this can vary, as all local councils have different zoning rules. A larger block will provide more flexibility regarding the design and layout.
Depending on the style of duplex you intend to build, you will require a wide or long lot. The size of your property will also affect many design and construction factors involving layout and local zoning regulations.
Choosing to subdivide your land will further impact the progress and cost of your build, with the subdivision process requiring a lot of planning before council approval is possible. Subdividing your land can also increase the overall cost of consultation fees, so we recommend ensuring all of these variables are accounted for when reviewing your budgets.
What will impact the cost of my duplex build?
In addition to the cost of subdividing your land, you can expect a few other factors to affect the cost of building, including contractor fees, material costs, location, demolition and more. Find out a bit more about these factors below:
- Tax costs
Property taxes during a new home build can inflate the cost of your home, with taxes, fees and charges contributing to 38% of the cost of a new home build in Melbourne.
- Structural engineering costs
A structural engineer ensures that your home’s plan is structurally sound and may prepare drawings and reports for council approval. Fees can vary depending on the home’s size or the project’s difficulty, ranging from $3,000 to $5,000.
- Connection of services
Connecting services such as electricity, gas, sewerage and water can take up to four weeks, and costs can vary depending on the size of your home.
- Location
In-demand areas may have higher land costs; however, this can also work to your advantage with public transport, local rental demand, and population growth, increasing land costs and investment potential.
- Land size
The size of the property, especially if in a high-demand area, can inflate costs, but a large lot can greatly offset layout and design restrictions.
- Materials
The materials you choose for your duplex, including construction materials, fittings, fixtures, and finishes, can inflate the price. This is primarily due to Australia’s labour and materials shortage caused by increased demand for home building services, bushfire impacts on timber supplies and an international construction material shortage.
- Contractor fees
Specialist contractors and subcontracting teams can add additional costs.
- Design fees
4.5% to 16% of the construction cost may consist of design or architect fees.
- Demolition
The demolition process can add costs of $12,000 to $20,000 if you’re considering a knockdown rebuild.
Building a custom home is a team effort involving experts in planning, design and construction. While this means great polished results, this process can be like waiting in line for a rollercoaster—it takes time, and you’re a bundle of nerves and excitement the whole way. Because of the time factor, you’ll need to account for accruing holding costs along the way, including loan repayments, land tax and council rates.
How long does it take to build a duplex?
The greatest hidden cost in any home build is time. The typical timeline for a build, from planning to final construction, can range anywhere from 6 to 20 months. A development application is a major factor contributing to the estimated timeline of a duplex build.
A development application is a legal document compiling information from your design and construction team and any other relevant service providers detailing the specified use or development you intend for a piece of land.
You can learn more about what goes into building a home here.