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 Floor Extensions
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.
EXCELLENT Based on 60 reviews A M2025-06-30Trustindex verifies that the original source of the review is Google. We recently had our house extension (3 rooms on ground floor) completed by Extension Unlimited. We couldn’t be happier with the results. From start to finish, Nick was professional, reliable, and very responsive to requests and clarifications. Nick and his team were very understanding and offered great suggestions and delivered high quality. Ritchie's workmanship has been excellent and the attention to detail really shows. The team kept disruption to a minimum, which made a big difference with a family still living in the house. We are very happy with the new build and would highly recommend them to anyone considering a home extension. Ar-Janine Bacanto2025-06-26Trustindex verifies that the original source of the review is Google. Our experience with Extension Unlimited is exceptional to say the less. The team is very professional, listen to our needs, explain every step-in details and given us a great comfort and fabulous results. • Starting from the reception who explained each step of the process. • Ted, the designer was very patience listening to our needs and requirements and came up with a great design. Making a few changes was not a big deal to him. • Penny who finalized the contract, permit application etc was great to work with. She explained every step thoroughly and gave us lots of comfort. • Ritchie and Travis – great team of carpenter who are always happy to come to work, did a great job and always clean and tidy up. Always explained in detail when we had any questions. A joy to work with. • The contractors of electrician, plumber, plaster, roof plumber and tiler engaged by Extension Unlimited are efficient and professional. • Nick our project manager – I had worked with a few sites managers in the past on various projects, but none can compare to Nick. His biggest interest is on client’s satisfaction and achieving excellent results. He kept us always informed on job schedule. The response time on phone calls and messages was always so quick and precious. He is a great leader of the team. • I strongly recommend Extension Unlimited to anyone. Matt Armstrong2025-06-04Trustindex verifies that the original source of the review is Google. I highly recommend Extensions Unlimited if you are looking to give your home a new lease on life and expand it to meet your family needs. Our extension was a complicated one, and completely transformed both the look and the functionality of our home. It is now a place we are proud to call our home! The EU staff and recommended contractors were amazing. Ted worked with us tirelessly to fine tune the design to meet our budget, whilst providing the "WOW". Emilio (our project manager) was a pleasure to work with and always had a solution for those head scratching moments. EU are a one stop shop having all experts under the one roof, which saved us both time and money. Luke Kennedy2025-04-12Trustindex verifies that the original source of the review is Google. We highly recommend Extensions Unlimited to anyone looking at either a big or small extension. The entire process from the initial enquiry with Sandy, design stage with Ted and construction phase with Nick was easy yet clear and detailed. We couldn't speak highly enough of Nick and his construction team. They are fantastic people, reliable and trustworthy. Jackson and Nicko were fantastic. Throughout the build we were consistently updated by Nick on what was happening and when. If there was a change in schedule it was communicated promptly and we always knew what was happening and when. 5 stars to all of the team at Extensions Unlimited. BabyG2025-03-23Trustindex verifies that the original source of the review is Google. We have had a wonderful experience with this company, starting with Spiro, and through out the entire build with the amazing team of Brett and his Team ( special mention to Jack). They always kept our comfort and safety in mind the whole time, even our fur babies and grown up kids were always kept comfortable and safe throughout the whole building period. We undertook a huge job with this company and essentially rebuilt our whole home and the final product is a fantastic custom home exactly as we imagined it. Thank you for making our dreams a reality and being so professional and thorough with your work. We can thoroughly recommend this team to anyone who is planning any sized renovation/extension. Thanks Tom and Alida Carmal Trumper2025-03-20Trustindex verifies that the original source of the review is Google. Thanks everyone, we couldn't be happier with the result! Our new extension is life changing and looks like its always been there. From start to finish the team were professional, available and incredibly patient (there were many questions!). The build itself moved quickly and we didn't even need to move out. We love our new home and highly recommend Extensions Unlimited. Anton Winter2025-03-13Trustindex verifies that the original source of the review is Google. We highly recommend Extensions Unlimited for their phenomenal work on our project. Our project manager Brett kept us informed of the progress throughout the build and his team were a pleasure to deal with on site. What sounded like a huge job to us was completed seamlessly and ahead of time. Penni, in the office was most attentive to our needs, no request was too hard. Thanks Extensions Unlimited. Chris Burridge2025-03-04Trustindex verifies that the original source of the review is Google. Great building experience. They were able to design an extension to exactly what we were after. Charles Juhasz2025-02-14Trustindex verifies that the original source of the review is Google. A huge thank you to the Extensions Unlimited team for their exceptional work on our project! From the start, Ted was incredibly patient and enthusiastic throughout the design process, ensuring every detail aligned with our vision. Once construction began, Emilio’s commitment and leadership made all the difference—his dedication to achieving our goals was evident in every step. The entire team was professional, attentive, and a pleasure to work with. We couldn’t be happier with the result and highly recommend Extensions Unlimited to anyone looking for a seamless and high-quality renovation experience! Thank you! Charles & Angela
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.
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?
How long does a typical house extension take to complete?
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