House extension is a great way to add extra living space and value to your home. There are many things to consider when planning a house extension, such as the cost, size, type of extension, building materials, council approval, and more. If you're trying to figure out how much your house extension will cost, keep in mind that there are a number of factors to consider when budgeting for a house extension, including the size and scope of the project, the type of materials used, and the cost of labour.
To answer that question we need to consider a few different things:
The cost of a house extension can vary considerably depending on the size and scope of the project, as well as the type of materials used. For example, a simple extension that adds an extra room to an existing home may cost around $20,000, while a more complex project that involves extending multiple rooms or adding a second storey could cost upwards of $100,000.
When budgeting for a house extension, it is important to speak with a professional builder or architect to get an accurate estimate of the costs involved. They will be able to take into account all of the necessary materials and labour costs, as well as any council approvals that may be required.
To give you a quick reference, here are the typical cost ranges for common extension types in Brisbane:
Extension TypeTypical Cost RangeNotesSingle storey rear extension$50,000 – $120,000Most common; depends on size and finishesDouble storey extension$90,000 – $200,000+Higher engineering and structural costsMaster bedroom + ensuite$30,000 – $55,000Typically 35–45m²Kitchen extension$40,000 – $80,000Plumbing and fit-out adds costLiving room extension$30,000 – $60,000Simpler if no wet areasRoom addition (general)$25,000 – $50,000Budget end for smaller additions
These figures include materials, labour, and standard council fees. The final cost will depend on your specific site, design, and finish level.
The type of extension has a big impact on your final cost. A single storey extension — the most common choice in Brisbane — adds space at ground level and is generally the more affordable option, with costs typically ranging from $1,800 to $2,800 per m². A double storey extension adds a second level and is more complex to engineer and build, usually coming in at $2,500 to $3,500 per m² or higher depending on finishes.
Single storey extensions are well-suited to larger blocks where you have room to extend outward. Double storey extensions make more sense where land is limited or where you want to preserve backyard space. Both types require Brisbane City Council (BCC) approval if they exceed certain size thresholds — your builder or certifier can advise on what applies to your site.
Building outward (single storey) is almost always cheaper than building upward. A ground floor rear extension avoids the structural complexity and engineering costs of adding a second level — no steel beams, no staircase, no reinforced footings required. That said, if your block doesn't have much usable land left, a second storey may be your only option and can still offer strong value by significantly increasing your home's floor area and market value.
The cost per square metre for a house extension in Brisbane typically falls between $1,800 and $3,500 per m², depending on the build type, materials, and complexity of the project.
Here's a more detailed breakdown:
| Build Type | Cost Per m² (Brisbane) |
| Basic single storey (brick veneer) | $1,800 – $2,200 |
| Mid-range single storey (rendered) | $2,200 – $2,800 |
| High-spec single storey | $2,800 – $3,500 |
| Double storey (standard) | $2,500 – $3,200 |
| Double storey (high spec) | $3,200 – $4,500+ |
These figures reflect Brisbane market rates. Costs in Sydney are typically 30–50% higher, while regional Queensland can be slightly lower. The per m² rate is useful for ballpark budgeting, but it's not the full picture — a small extension often has a higher per m² rate than a larger one because fixed costs (council fees, site prep, connections) are spread across fewer square metres.
To give you a better idea of costs for a house extension in Brisbane, let's look at a few real examples:
The cost of a 50m² outward extension in Brisbane typically costs between $50,000 and $70,000. This price includes the cost of materials, labour, and council fees. If you are planning an upward extension of the same size, the estimated cost is between $70,000 and $100,000.
If the material used is brick veneer the cost would be on the lower end of the price range, while if you are using render the cost would be at the higher end.
If you are planning to extend your home by 50m² or more, you may need to obtain council approval. The cost of council approval can vary depending on the size and scope of the project, but generally ranges from $200 to $2,000.
The cost of a master bedroom and ensuite extension in Brisbane typically costs between $30,000 and $40,000. This price includes materials, labour, and council fees. A master bedroom and ensuite will typically need a minimum of 35m². If you're adding high-end fixtures or walk-in robes as part of the build, budget toward the upper end or beyond.
A kitchen extension is one of the more complex room types to add because it involves plumbing, gas, electrical, and kitchen fit-out costs on top of the structural build. In Brisbane, a kitchen extension typically costs between $40,000 and $80,000, depending on the size and the quality of cabinetry and appliances included.
If you're extending an existing kitchen rather than adding a new one from scratch, costs can be lower — but you'll still need to factor in tiling, benchtops, and relaying services.
A living room or lounge extension is one of the more straightforward extension types as it rarely involves wet areas or complex services. In Brisbane, costs typically run from $30,000 to $60,000 for a decent-sized addition. Open-plan designs that connect the living area to an outdoor entertaining space are very popular in Brisbane's climate and can add significant liveability and resale value.
If you're simply adding a single room — a bedroom, study, or utility room — costs in Brisbane start from around $25,000 for a basic addition and can climb to $50,000 or more for larger or better-finished spaces. Adding a room to an older Queensland home can sometimes involve additional costs for subfloor work, tie-in to the existing frame, or matching weatherboards or cladding.
Not all extensions are the same. Understanding the different types can help you choose the right solution for your home and budget.
The most common type in Brisbane. This extends the back of your home at ground level, typically adding a new room or opening up an existing living area. Ideal for homes with a longer block that has usable backyard space. Because there's no upper level involved, this is usually the fastest and most cost-effective extension type.
Where a rear extension isn't possible — due to pool position, a small backyard, or easements — a side extension may be the answer. This uses the side yard to add width to your home. Side extensions are common in inner-Brisbane suburbs where lots are narrower and rear yards are smaller.
Adds a full upper level to an existing single storey section of the home. This is a significant build — it requires structural engineering, a staircase, and often temporary propping of the existing roof during construction. The payoff is a large increase in floor area without using any more of your block.
Some Brisbane homeowners extend both out and up — adding a ground floor addition to the rear and building a first floor above an existing section of the home. This is the most complex and expensive option but results in the greatest floor area gain.
A smaller, more targeted approach — adding a single room such as a bedroom, study, or sunroom. Often the right choice when you have a specific need (a growing family needing one more bedroom) rather than a broader desire to increase the home's overall size.
A great way to help you estimate the cost of your house extension project is to use a house extension cost calculator. There are many different calculators available online, and they can give you a useful ballpark figure before you get into detailed quotes.
When using a house extension cost calculator, you'll need to input details like the size of the extension, the type of build, and your preferred materials. The calculator will then provide an estimate of the total cost.
It's important to remember that the estimate provided by a calculator is just that — an estimate. The final cost of your project will depend on your specific site, your builder's rates, and the finishes you choose. For an accurate figure, speak with a professional builder or architect. If you're looking for a quote, feel free to contact us at Livit Constructions Brisbane.
For most Brisbane homeowners, a well-planned house extension is absolutely worth it — and the numbers generally back that up.
Yes, in most cases a quality house extension adds more value than it costs. An extra bedroom, a larger open-plan living area, or a master ensuite can meaningfully increase your home's market value, particularly in Brisbane's property market where space is at a premium. Extensions that add functional rooms — bedrooms and bathrooms especially — tend to produce the best return on investment.
The key is ensuring the extension is well-designed and suits the scale and style of the existing home. A poorly executed addition or one that feels disconnected from the original house can have a neutral or even negative effect on value.
If your primary goal is to boost property value, focus on extensions that buyers actively look for:
Sunrooms, studies, and outdoor living areas add liveability but typically have a lower direct impact on sale price.
House extensions on a budget are achievable — but they require clear priorities and a realistic scope.
If you're working to a tight budget, focus on a single well-designed addition rather than trying to do too much at once. A single storey rear extension with standard finishes will always deliver better value per dollar than a complex double storey with high-spec materials.
Affordable house extensions in Brisbane don't have to mean cheap finishes. It means smart design — maximising the usable space of every square metre you build and avoiding over-specifying in areas where the investment won't show in value or liveability.
Builders like Livit Constructions work with homeowners across Brisbane's southside to find practical extension solutions that fit real budgets. Getting a clear fixed-price quote upfront is one of the best ways to control costs.
The reason house extensions are so expensive in Australia is due to the high cost of labour and materials. In addition, many house extensions require council approval, which adds to the overall cost of the project.
Unlike new builds where you're starting from scratch on a clear site, extensions have to integrate with an existing structure. That means matching existing materials, working around live services (electrical, plumbing), and often dealing with older construction methods that require upgrading to current code. This complexity is part of what makes extensions more expensive per m² than a comparable area of new construction.
The expertise and experience of your builder is also a significant factor. An experienced extension builder will find the most efficient way to achieve your goals and avoid costly surprises during construction.
While you may not need an architect for a small extension, most larger extensions benefit from one — and some will require one. An architect can help you design an extension that maximises your space, respects the character of your home, and meets all relevant building codes and regulations.
One of the most common questions homeowners ask is whether they need planning permission to extend their house. In Brisbane, this depends on the size, location, and type of extension you're planning.
Under Brisbane City Council rules, many extensions can be approved as a Code Assessable Development — meaning a private certifier can approve them without a full council DA, provided the design meets the relevant benchmarks in the Brisbane City Plan. This is typically faster and cheaper than a full impact assessment. Extensions that fall outside those benchmarks — for example, those that are larger than standard, closer to boundaries, or in heritage-overlay zones — will need a development application (DA) submitted to BCC directly.
As a general guide, you'll typically need some form of approval for any extension over 10m² that is attached to the dwelling. Your builder or a building certifier can review your specific site and advise on the right approval pathway before work begins.
Timeline is one of the most common questions alongside cost. As a rough guide:
These are indicative figures. Site conditions, weather, material lead times, and the complexity of the tie-in to your existing home all affect the timeline. Your builder should provide a construction program before work starts so you know what to expect at each stage.
A small extension may not be worth it if the cost of materials, council fees, and labour is high relative to the value it adds. However, if you're looking to add a specific room — a bedroom, bathroom, or living space — that genuinely improves how you use your home and increases its value, a small extension can absolutely make sense.
The key question to ask is: what problem am I solving? If the answer is clear and specific — we need one more bedroom, we need a bigger kitchen — a well-planned small extension usually delivers a strong return.
Generally, the cost of house extensions in Brisbane falls on the lower end of the price range compared to Sydney. A small extension in Brisbane may cost as little as $20,000, while the same extension in Sydney could cost upwards of $60,000. The reason for this price difference is the higher cost of labour and materials in Sydney. In addition, many house extensions in Sydney require council approval, which can add to the overall cost.
Brisbane extension costs are also typically lower than Melbourne, though the gap is smaller than with Sydney. Melbourne's inner-city labour rates and heritage overlay rules in many suburbs push costs higher. Brisbane's relatively newer housing stock and more streamlined council process generally make it a more cost-effective place to extend.
Livit Constructions works across Brisbane, including the southside suburbs of Sunnybank, Carindale, Wishart, Mansfield, Rochedale, Underwood, Eight Mile Plains, Springwood, Loganholme, and surrounding areas. Southside Brisbane has a high concentration of older Queensland homes — many from the 1970s to 1990s — that are well-suited to rear and side extensions, adding bedrooms, open-plan living areas, or master suites.
We understand the local housing stock, the Brisbane City Council approval process, and the typical site conditions across the southside. That means fewer surprises and a smoother build for you.
If you're based in Brisbane's southside and looking for an extension builder who knows your area, we're happy to come out and assess your property. Get in touch for a no-obligation quote.
Overall, the cost of house extensions in Brisbane is relatively affordable compared to other major Australian cities. The final cost will depend on a number of factors specific to your home and project, so it's always best to speak with a professional builder or architect to get an accurate quote. If you're ready to take the next step, contact Livit Constructions Brisbane today.
