BK-Renovation and House Extension Costs in Melbourne BK
  • BK-Renovation and House Extension Costs in Melbourne BK


    One of the most frequently asked questions when people first contact us with is ‘How much does an extension cost for my Melbourne home?’ Of course this is a reasonable question early on when you are considering alternatives and what’s possible. A specialised extension builder can certainly assist in early ballpark figures where families need a guide as to how much a single storey or second storey extension will impact on the budget. At Extensions Unlimited, our in-house experienced building designers can give very good indicators of the cost of building an extension, even if you have no design at all. From our experience of over 25 years, we can give you a fairly reasonable ballpark figure − sometimes even over the phone. And we’ll endeavour to provide solutions that work with your financial situation.

    Should this initial ballpark cost of extension be within the realms of your budget, then further conversations can take place, like coming up with a concept design based around the initial budgets discussed.

    Considering a House Extension But Unsure of the Costs that Could be Involved?

    Many families dream of extending their home but are put off by renovation and house extension costs in Melbourne. However, the cost of a house extension might not be as high as you think − especially if you engage honest and reputable house extension builders like the team at Extensions Unlimited. Whether you have a growing family or you simply want to enjoy more spacious living, we can help you work out all renovation and building costs involved so you can get an idea of what the total amount will be.

    Factors to Consider When It Comes to House Design & Extension Cost

    There are a range of factors that come into play when determining the cost of a house extension. For example, the answer can vary widely depending on whether you’re asking how much does a single storey extension cost or how much a double extension will cost. While double extensions can be more expensive, our team can help you work out the difference between single storey vs. double storey extension cost. Other factors that can impact cost include:

    • The lay of the land (Is it flat or sloped? Are there trees that will need clearing?)
    • Site access (Does the site allow easy access for vehicles and equipment?)
    • Engineering requirements of the extension (Is complex engineering needed?)
    • Whether the builder you’re using offers an end-to-end house extension solution by having designers, permit officers and building departments under the same roof (like Extensions Unlimited).

    Opportunity Cost When Considering a House Extension

    Before deciding on a house extension, it’s important to consider opportunity cost. This is where you need to ask yourself if the extension you’re planning really the best option for you and your family in both the short and long term. Part of this involves considering the upfront cost of restructuring rooms and determining if it’s cheaper to build up or to build out (i.e. a single or double storey extension).

    You also need to consider opportunity cost in the long term. For example, if you build a double storey extension now, how will this impact your kids as they grow up? Or if you opt for a single storey extension, will you still be able to put a pool in the backyard? These are all important things to think about before you make a final decision.

    Discover the Extensions Unlimited Difference

    Extensions Unlimited is one of Melbourne’s most trusted and experienced extension and renovation design and build companies. Consider us your one-stop hub, with all designers, permits officers and building departments under the same roof. Why is this important? We are not disjointed middlemen peddling plans and/or permits then assisting you to then engage a separate builder. We encompass all facets, including design, drawings, permits and construction. There will be no dispute between your builder and another architect or the designer and the builder. It’s all one streamlined and cost-effective system where everyone is on the same page. No middle-men, potential backdoor payments or shady deals by ‘helpful brokers’.

    Why a One Team Approach is Best

    The great thing about working with one team under one roof is that we can answer all your questions as they come, which is highly important in the initial design process. For example, if you want to know is it cheaper to build on or build up, or you’re tossing up between a new build vs. extension, our supportive staff can provide you with the information you need to make an informed and educated decision.

    Once we have worked together to come up with your FREE design, we can then give an even more accurate assessment of what we believe the final cost will be. We will discuss potential costs during the permit progress as well as any finishing costs that you may incur that are beyond our scope of works − an ‘overall’ cost if you will.

    Expert Service and Advice Tailored to Your Needs

    At Extensions Unlimited, our experience is that architects and draftspeople do not give good or accurate advice for a number of reasons. Firstly and predominantly, they are not builders and they quite often fail to see the impact of many site variables on the cost of the proposed addition i.e. access, trees, difficulty, power lines, landscaping and the amenity of the Client (can the client live in the house during construction?). The designers that operate outside of a building company do not have the knowledge or access to all facets of the build at their fingertips as the designers do here at Extensions Unlimited. So asking them ‘is it cheaper to add on or build up?’ instead of putting the question to a licensed and accredited builder won’t necessarily do you any favours. The unfortunate result is often a nice design that is impractical, not family friendly and unaffordable after you have spent thousands on design drawings.

    For reasons noted above, every extension and renovation is different, therefore initial estimates can only be accurate if done by a company and its staff that work constantly in this space over many years and have great hands-on knowledge that’s applied to each particular job.

    What to Look for in a Renovation / Extension Builder

    Just remember that a builder with a good reputation and experience will offer a free fixed price quote before you spend one cent, should the design and budget suit your goals. From there, you would enter a Preliminary Works Contract (of which the cost is included in the initial fixed quote) to move forward with working drawings based upon the design quoted. This will also determine any changes to what’s included and what’s not.

    We want to be clear that the fixed quote can change where the soil report and subsequent engineer’s assessment requires it, and where the energy report may require upgrades to windows or insulation beyond that already allowed for in the fixed quote.

    So Back to the Initial Question − How Much Does an Extension Cost?

    Generally, second storey additions range from $140K to infinity, with the average being between $170K and $270K total end to end. Of course, we regularly do many projects beyond this price point. Ground floor additions are much harder to give an estimate on, as there is a lot more to consider such as access, demolition, overall scope of works, and required internal renovation, so for that reason it is better that you speak to one of our experienced designers.

    We do not build for architects. We build our own designs. We get our own permits and complete the permit process in-house. Then we do the build for you, all within one building, with one person to be your direct contact at each stage.

    A ‘one-stop’ professional builder is much more cost-effective than a middleman farming off work to individuals who do not communicate with each other and trying to ‘package’ different boxes together.

    Contact Us Today for a No-Obligation Quote – We Love Questions!

    If you’re still pondering the question ‘How much do extensions cost per square metre?’, contact Extensions Unlimited for a quote today. Our knowledgeable team have years of experience in extensions and can provide solutions to almost any house extension problem you can think of. In addition to providing accurate quotes, we’re also happy to share our extensions expertise by answering any questions you might have.

    Designed together Built by us Enjoyed by you



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


To start the exciting journey towards your extension dreams, or for just a general enquiry, please contact us using this form.