House Extension Costs in Melbourne

  • House Extension Costs in Melbourne


    The desire for more space is common for Melbourne homeowners. As families grow and needs evolve, a fresh start isn’t always the answer. Extending your existing home offers a compelling solution, adding valuable square footage without the upheaval of moving. But the question that lingers on everyone’s mind is: how much does a house extension cost in Melbourne?

    While there’s no one-size-fits-all answer, this comprehensive guide from Extensions Unlimited, Melbourne’s trusted home extension builders, aims to shed light on the factors influencing house extension costs and give you the knowledge to make an informed decision.

    Getting a quote for a home extension

    Before diving into the nitty-gritty, let’s address the burning question. We understand the importance of budget transparency. At Extensions Unlimited, we offer free, no-obligation quotes. This initial consultation allows us to assess your specific requirements and provide a clearer picture of the potential costs involved in your dream extension.


    Understanding Price Variations: Second Storey vs. First Floor

    The cost of your house extension will primarily depend on the type of extension you choose. Here’s a breakdown of the general cost ranges for Melbourne extensions.

    First Floor Extensions

    Ground floor extensions provide the opportunity to expand your living space outwards, potentially creating a more seamless connection to your backyard. This type of extension can be ideal for adding a larger kitchen and living area, an additional bedroom, or even a home office. However, ground floor extensions can have more variable costs compared to second storey additions.

    Site access plays a significant role. Limited access to machinery and materials can necessitate creative solutions, potentially impacting the budget. Demolition of existing structures or significant excavation work required for foundations can also add to the cost. Additionally, the overall scope of internal renovations needed should be factored in. For instance, will the extension require structural changes, or plumbing and electrical upgrades to integrate seamlessly with the existing house? These factors contribute to the variability in first floor extension costs. Consulting with our reputable local builders for a customised quote is crucial to get a more accurate picture of the potential prices involved in your specific project.

    Second Storey Addition:

    Second storey additions offer an attractive solution for maximising space without sacrificing valuable backyard area. They’re generally quicker and more cost-effective per square meter compared to first floor extensions due to less foundation work required. However, there are still factors that can influence the final cost.

    The complexity of the roof structure plays a role. A simple gable roof will be less expensive than a multi-faceted or skillion design. Additionally, if your existing house requires significant structural reinforcement to support the additional storey, this can add to the final cost. That being said, second storey extensions typically offer a predictable cost range, falling within the $260,000 to $350,000 range for most projects in Melbourne.

    Key Factors Influencing House Extension Costs

    Now, let’s delve deeper into the key factors that can significantly impact the final price of your house extension project:

    • Size and Complexity of the Extension: As expected, the larger and more complex your desired extension is, the higher the cost will be. This includes the square meterage of the addition, the number of storeys added, and the presence of intricate architectural features.

    • Site Access and Engineering Requirements: The ease of access for machinery and materials to your property can influence the cost. Sloped sites, limited access points, or the presence of mature trees that need removal can all add complexity and potentially increase costs. Similarly, engineering requirements for foundations, support beams, or specific materials can also impact the final price.

    • Materials and Finishes: The type of materials you choose for your extension will play a significant role in the overall cost. High-end finishes, customised joinery, or specific building materials can elevate the aesthetics and functionality of your extension but will also come at a premium price.

    • Demolition and Excavation (Ground Floor Extensions): For ground floor extensions, any demolition of existing structures or significant excavation work needed will add to the overall cost.

    • Permits and Approvals: Obtaining the necessary permits and approvals from your local council is an essential step in the extension process. While we take care of this for you, these permits typically incur fees that will be factored into the quote.

    • Builder Expertise and Experience: A reputable and experienced extension builder like Extensions Unlimited can offer valuable cost-saving insights and ensure efficient project management, ultimately contributing to a more cost-effective outcome.

    The Value of a Well-Planned Extension

    While cost is undeniably a crucial factor, it’s important to consider the long-term value a well-planned house extension can bring to your property. Here are some key benefits to consider:

    • Increased Living Space: House extensions offer a practical solution to address space constraints. Whether you need extra bedrooms, a dedicated home office, a larger living area, a new kitchen, or simply a more functional layout, an extension can significantly enhance your living comfort.

    • Boosted Property Value: A well-designed and executed house extension can add significant value to your property. The additional square footage, improved functionality, and modern updates can make your home more attractive to potential buyers in the future.

    • Enhanced Lifestyle: A well-planned extension can transform your living experience. Imagine a dedicated space for hobbies, a luxurious ensuite bathroom, or a seamless indoor-outdoor connection to your backyard – these improvements can significantly enhance your day-to-day life.

    Our Home Extension Process



    Free initial meeting with our house extension designer for customised solutions.



    We’ll get council approval and permits. Taking care of any fees for you.



    Design Development, Preliminary Works Agreement, Final Contract.



    Independent surveyor indspections. Final certificate upon completion.

    We offer a comprehensive approach designed to streamline the experience and ensure a cost-effective outcome. Here’s what sets us apart:

    • Free Design Consultation: Our experienced design team will work closely with you to understand your vision, lifestyle needs, and budget constraints. We’ll translate your ideas into a detailed design plan that maximises functionality and aesthetics while remaining mindful of cost considerations.

    • In-House Expertise: Extensions Unlimited operates as a one-stop shop for all your house extension needs. We have a team of experienced designers, permit specialists, and builders under one roof, ensuring seamless communication, efficient project management, and a more cost-effective approach. No need to juggle multiple contractors or navigate communication gaps – we handle it all.

    • Transparent Pricing: We believe in transparency throughout the entire process. You’ll receive a detailed breakdown of all costs involved, including materials, labour, permits, and potential unforeseen circumstances. This allows you to make informed decisions and avoid any hidden costs and surprises during construction.

    • Exceptional Customer Service: We prioritise open communication and maintain a dedicated project manager as your point of contact. Our team is readily available to answer your questions, address any concerns, and keep you informed throughout the entire project duration.

    Based on 44 reviews
    Ksana Playfair
    Ksana Playfair
    We highly recommend Extensions Unlimited if you are looking to complete an extension to your home! My first phone call to enquire, I spoke to Sandy Pavey who explained the entire process and immediately put me at ease. Ted Bolte, our designer, listened and understood our vision and worked closely with us as we arrived at a design for our extension/renovation that we were excited about. Penni Winter, the pre-construction manager, has unending patience dealing with council and was always reassuring. She seamlessly manages everything leading up to the start of construction. Brett Harvey, our builder and project manager, was a delight to work with. He is responsive, calm and always happy to discuss questions and explain everything. We found all the trades that came into our home were fantastic - the quality of work is great and everyone was friendly and always happy to have a chat and answer questions. From start to finish, we always felt that our home was in good hands and everyone involved was invested in giving us a home our family will enjoy for years to come. Thank-you Extensions!
    Stephanie Jordan
    Stephanie Jordan
    Extensions Unlimited were simply amazing! From the very first point of contact to the handover at the end, it was just seamless, much like a well-oiled machine. Barry West, the designer, listened to what we wanted and came up with a design we were so happy with. He has a real eye for detail and made our second storey extension blend seamlessly with our existing period home. Brett, our Project Manager was great too and kept us informed via sending us schedules every few weeks. He was always available to take our call if needed and very helpful. We lived in our house while the second storey went on; we were a bit worried how we would cope, living in a construction site, but it honestly was so easy. We would recommend Extensions Unlimited to anyone looking for a builder. We are over the moon with our result!
    Dave Burt
    Dave Burt
    Very happy with our new extension and the experience we received through Extensions Unlimited. Its certainly turned our home into a very functional space for our growing family! From the design, to dealing with council, prebuild and building we found the process fairly streamlined. We appreciated the communication and organization we received from our project manager- things happened when he said they would (Thanks Nick!). We had a three year old who was heavily involved in the building process and we especially loved how the crew would engage his love for all things construction (Thanks Richie, Trav and PJ). We found all the contractors to be professional and the team really responsive to anything that we weren't quite sure about. Would certainly recommend Extensions Unlimited for anyone considering an addition to their home.
    Fapiola Tapusoa
    Fapiola Tapusoa
    We had the most amazing experience with Extensions Unlimited. They listened, they communicated and they delivered. I can't praise them highly enough for their prompt response, transparency and their professionalism. Living in the house through an upstairs extensions and renovations with three teenage girls and a dog was not so bad after all. Our Designer, Barry, was so dedicated and patient, went above and beyond to make sure we were happy. Emilio our Project Manager is calm, trustworthy and very understanding, made this journey most enjoyable and stress free. Shane and Lachie for their excellent craftsmanship. Always keep things tidy and clean. Penny in the office, always ready to assist. To sum them up - “They Care”
    Vincent Zhou
    Vincent Zhou
    It has been a great pleasure to work with Extension Unlimited (EU) team in the last 2 years on our home extension (up) project. EU has such a capable and supporting team that made our extension journey a smooth process. Special thanks to Emilio for his effective project management and meticulous execution; Shane and Lachie for their workmanship; Penni for her patience in obtaining all the permits; PJ for his final touch. All tradies involved in the construction have done a fantastic job. We would highly recommend EU team for your extension/renovation project.
    Igor M
    Igor M
    It was a pleasure dealing with the EU Team, who delivered the project on time and on budget. From our first meeting with Ted who helped us to design our second floor extension, to Penni and the office staff who were always there to assist us. Our Project Manager Nick and his team were professional and wonderful to deal with. Nick was very proactive in keeping us up to date and ensuring everything is on track. I would highly recommend engaging the EU Team for any of your renovations needs.
    Ainsley Fernandez
    Ainsley Fernandez
    Thank you Extensions Unlimited for doing a wonderful job on my extension. New 4th bedroom, kitchen, laundry, extra bathroom and toilet and a walk in pantry to boot. A very, very big thank you to Emilio, my project manager, so pleased to have you as my manager, always there to make things happen. I was always happy to see you and will miss you coming round to check on progress. Thanks also to Barry for designing the fantastic extension and Penni for keeping me informed of progress with the permits etc. Lastly thank you PJ for clearing the site of all the extra building material. Job well done. Highly recommended company for renovations.
    Zena Cadman
    Zena Cadman
    We extended our home (up) with Extensions Unlimited and we could not recommend them enough! The process from start to end delivered what we wanted and more. On time and on budget. The ladies in the office were very professional, friendly and always answered any questions we had about the process. Ted was our designer and he was just terrific with us and really listened to our suggestions. The final result was better than we hoped. We could not have asked for a better project manager in Nick. Nick is amazing at what he does, is very professional and always took the time to listen and explain anything we didn't understand. We lived in our home through our extension and Nick always considered our needs through the build. Ritchie and Travis were our carpenters and they are just awesome at what they do. All of the trades involved in the build were highly professional and all did a great job. We want to thank everyone at Extensions Unlimited including the owners for helping us build our dream spaces upstairs. We absolutely love our home!
    Greg and Emma McDonald
    Greg and Emma McDonald
    We engaged Extensions Unlimited for a second story renovation of a free standing house on a strata title. Our appointed designer Barry was fantastic and really made our vision of what we were trying to achieve come to life. He listened to all our needs and kept the charm of our California bungalow as requested, as well as designing a functional internal space, giving us the second living zone we wanted as our kids approached the teenage years. Penni in permits was great and guided us seamlessly through this portion getting us to building stage. Our appointed project manager Emilio was super. He was a pleasure to deal with and helped us navigate living through the build. The appointed trades were fantastic and did a fabulous job. The company directors were great at checking in and letting us know they were available if needed.
    Marnie Horne-Spalling
    Marnie Horne-Spalling
    Wow! Our extension looks amazing!! The professionalism from Extensions Unlimited was outstanding through the entire project!! Even through the height of covid, our design consultations were still accommodated through zoom meetings. Thank you, Ted, for a lovely design, he listened to everything we asked for and nothing was ever considered outrageous or too hard. We were converting our outdoor patio into an indoor living space, the patio was filled with natural light, this would be our main source of light through to the kitchen, we were concerned that the natural light would disappear with the extension, so we asked if this could be replicated within the new space, this wasn’t an issue, Ted added two large beautiful velux roof windows to accommodate this, what an amazing feature, the house is beautifully lit with natural light, its so beautiful seeing the blue sky and the stars at night!! The pre-construction phase is always a daunting time for any build, engineers, soil tests, you name it, all part of the process. Penny and team put us at ease, they were always quick to answer any concerns we had, and explained in detail, any questions about the contract. Our construction team was sensational, Nick, our project manager, would communicate everything to us through text message, would text us both, which we highly recommend, Trade schedules and times were always clearly communicated, all the trades were always on time’ all extremely hard working and professional. Even with small delays of materials, like our roof trusses, Nick would always let us know. Our builders Ritchie and Travis were great! Very friendly, we were in each other’s lives for 8 months, even on the hard mornings getting the kids to school and work, they always understood and kept a friendly attitude. Thank you, Shane, our plasterer, for making our roof and extension look seamless, the workmanship is beautiful. If you want a professional and a stress-free extension, then look no further than Extensions Unlimited! Mark & Marnie. Endeavour Hills

    Enquire with Our Home Extension Builders

    Ready to unlock the potential of your Melbourne home with a well-planned house extension? At Extensions Unlimited, we’re passionate about transforming houses into dream homes. Contact us today for a free, no-obligation consultation. Our experienced team will guide you through the process, answer your questions, and provide a free initial design to help you visualize your dream extension.

    Frequently Asked Questions on Home Extension Costs

    Is it cheaper to extend up or out?

    This depends on several factors. Second storey additions can be more space-efficient, but factors like site access, engineering requirements for foundations, and existing roof structure can impact the cost. The final cost for a second floor extension generally falls within the $260,000 to $350,000 range. Ground floor extensions might require less complex engineering but may involve demolition or excavation work, adding to the overall cost. Our recommendation? Contact Extensions Unlimited for a free consultation to determine the most cost-effective option for your specific property.

    What financing options are available for house extensions?

    There are two options available when it comes to home extension payment schedules: Method A and Method B.

    Method A is used generally for new home builds as the payment schedules reflect the standard stages of construction.

    For an extension / renovation Method B allows the builder and the client the flexibility to stay in their home as extension works are progressing, thus avoiding potential costs of moving out and having to rent a property for the duration of the build.

    How long does a typical house extension take to complete?

    The timeframe for a home extension project can vary depending on the size, complexity, and any unforeseen circumstances. Generally, second floor additions can take anywhere from 3-6 months, while a ground floor extension might take slightly longer due to potential demolition or excavation work. Extensions Unlimited will provide a realistic timeline during the initial consultation and keep you updated throughout the construction process.


We would like to express our gratitude to you & your team for your recently completed Project of a second storey addition to our existing weatherboard home. From our first meeting with the Designer, we were confident in his enthusiasm for the business & his passion to design an extension...

Steve & Sophie – Ringwood Nth

It was a great experience and was handled with great care. It could have been a stressful time with a toddler, newborn, two dogs & a home extension. But it was really good & we really love our new space and home.

Ryan & Lisa – Viewbank

We purchased in an area we loved & that was a major factor in making the decision to extend...we loved the idea of being able to create something that suited our needs.

Alex & Sam – Knoxfield

Right from the first phone call we found the whole team at Extensions Unlimited to be very attentive and professional. The Design Consultant listened to our requests, and came up with a design that suited our needs and existing construction. Once the work commenced, we had fairly tight deadlines due...

Brenda – Glen Waverley

Our initial contact with the company was great. The Design Consultant met us for our first appointment and listened to our ideas and came up with a design which was exactly what we were looking for. The process was very easy and construction started after only a few months of...

Michael & Natalie – Nunawading

Very happy with our upstairs extension. The company stood out from the very beginning in terms of customer service as well as promptness and clarity of communication.Our project was finished on time and within budget. Have to especially acknowledge our Project Manager and our Designer. Our Designer was very patient...

Harish – Essendon

We opted for Extensions Unlimited purely based on our experience with our Designer. We were impressed by his professionalism & conscientiousness in finding the best design for our needs. Moreover, we felt he was someone we could trust. In fact, all Extensions Unlimited staff members were professional & friendly, so...

Stephen & Kim – Glen Waverley

Excellent Project Management! Communication was always clear, precise, timely & trustworthy. The whole extension / renovation process was well handled and we enjoyed the journey.

Huei & Chin-Wei – Mount Waverley


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