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How much does a second storey addition cost?

$1,800 - $3,300 per m2

    How much does a second storey addition cost?

    The cost of adding a second storey to a house starts at around $1,800 to $3,300 per square metre. If you want to add a 100 square metre addition, you’ll spend on average spend between $185,000 and $330,000. This does not include the cost of any plumbing or electrical work that you need. The cost can also depend on the materials that you choose and where you live. Below are the hourly labour rates for a carpenter, which you will likely need to help build your second storey addition.

    Below is a cost list for the average hourly rates for professional carpenters across cities throughout Australia:

    City Average Cost (per hour)
    Sydney $40
    Melbourne $45
    Brisbane $45
    Canberra $50
    Perth $45
    Darwin $45
    Hobart $40
    Adelaide $50

    Benefits of adding a second storey to your home

    Increased living space
    Adding a second storey will increase the amount of space you have a potentially improve your quality of living at home. You can use that space to add a living room or family room as well as more bedrooms or a larger kitchen. It even allows you to create a rental apartment and earn extra money every month.

    Increased home value
    A new addition to your home can increase the value of your house too. Even if you don’t want to sell your home in the near future, you can raise the property value.

    Do second storey additions cost more than ground floor additions?

    The average cost of a two-story addition is usually lower than the cost of extending your ground floor. The foundation is a major expense that contributes to the cost of ground floor extensions. However, the cost of a second storey addition can still add up to be expensive and will disrupt your home a lot during the process.

    Factors impacting the cost of a second storey addition

    Home size
    One factor that impacts your cost is the size of your home. If you have a home with more square metres, you’ll pay more for a second storey addition than someone with a smaller house would. This is often due to the home addition size you need to match the rest of your home.

    Types of rooms and how many
    The cost to add a second storey will depend on the type of rooms that you want in the addition and its overall size. You can usually save money when you go with simple rooms such as a living room or rec room along with bedrooms. Adding plumbing for a kitchen or bathroom will increase your cost.

    A white two storey house with a front yard

    A second storey addition does not have to be the same size as the ground floor / Source: Buildtech Homes

    Choosing different materials can affect your price too. If you choose more expensive floorboards, windows, paint, and fixtures etc. the cost of the addition will increase a lot. While you can lower your double-storey extension cost with cheaper materials, remember that they might not always be as durable or safe.

    Your second story addition cost will also depend on whether you need to relocate during the construction temporarily. If you move your family to a hotel, look for one with extended stay rates. These hotels offer all the comforts of home such as a small kitchen with appliances but charge weekly or monthly rates. You might ask family and friends if you can temporarily live with them too.

    How many contractors you need 
    Don’t forget to factor in all the different contractors who you need for the job. If you want a kitchen or bathrooms upstairs you will need a plumber to install the pipes and make sure that the plumbing works. You will also need an electrician to install lighting and powerpoints.

    How to hire a builder

    How to create an accurate estimate:

    • Get multiple quotes: Shop around to different builders and contractors to receive a number of different quotes before deciding on one company or professional. This will allow you to get a good understanding of what the industry standard is in terms of costs.
    • Be specific: Be as detailed and specific as you can when talking to professionals about what you want. This relates to how many rooms you want to be built, what type of materials you would like, and what time frame you want the job completed in. This will allow the quotes to be as accurate as possible
    • Be realistic: Be prepared to add on up to 10% of the initial cost quoted to you in preparation for delays and other unforeseen issues with the build. This is common with second storey home additions.

    Licensing and qualifications
    Builders working in Australia need to meet the requirements in their states. This often includes a minimum of two years working under a licensed builder or some experience working as a subcontractor. Builders usually need a Diploma of Building and Construction too. Use Licensed Trades to make sure you pick a builder with the qualifications to work in your state.

    How to save money hiring a builder

    Make sure to do thorough research before hiring a builder. Look online at reviews of their work and ask family or friends if they have any good referrals for you. This way you will be able to find a builder that has the best rate that will work for you.

    Also, see if the builder works with a team of contractors and subcontractors. If you need to go through multiple builders or hire contractors for all of the jobs that you need, your price will go up. Some builders can handle all of the work that you need for a set price.

    * The cost data is based on Oneflare and third-party sources


    How much does a staircase cost to build?

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    If you add a second storey to your home you will need to have a staircase built to access it. A staircase ranges from $1,000 to $4,000 for a basic design. For custom stairs that you or your builder designs, you might spend as much as $30,000.

    Can you live in your house while adding a second storey addition?

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    It is normally difficult to remain living in your home during a second storey addition and you will find it helpful to temporarily relocate to a loved one’s home or a hotel. Living in a construction zone is hard. You’ll hear the sounds that the workers make every day, which can be quite loud as they demolish old features. Many people don’t want to worry about the dust and debris flying through the air either.

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