Cost to Build a Second Story: Complete Guide for Murrumbeena

Trying to nail down the cost to build a second story can feel a bit like guesswork, but if you’re a homeowner in Murrumbeena, a realistic starting point is around $450,000. Of course, for more complex or high-end projects, that figure can easily climb to $750,000 or more. The cost is affected by many factors such as site access, design complexity, the existing structure, size, and your choice of fixtures and fittings. There is no one-size-fits-all price, as second storeys are custom-built and unique to the existing home.

Your Murrumbeena Second Story Cost Snapshot

There’s simply no "one-size-fits-all" price tag when it comes to adding a new level. Think of it less like buying something off the shelf and more like commissioning a bespoke piece of furniture. The final cost is a direct reflection of your home's unique character, your design dreams, and the specific challenges of your property.

That initial number isn't just pulled out of thin air; it’s shaped by several critical factors that every homeowner needs to weigh up. The journey from a simple idea to a finished upper level is a detailed process that involves much more than just framing up a few new rooms.

Key Factors Shaping Your Budget

Getting a handle on what drives the cost is the first step toward building a realistic budget. For a home in Murrumbeena, the main variables you'll be looking at include:

• Your Existing Structure: Is your current foundation and wall framing strong enough to support an entire new floor? An engineer's assessment is non-negotiable and might reveal the need for costly reinforcements.
• Size and Complexity: It goes without saying that a simple, rectangular addition with two bedrooms and a bathroom will cost significantly less than one with multiple rooms, soaring vaulted ceilings, or a unique architectural footprint.
• Site Access: Properties on tight or sloped blocks in Murrumbeena can throw a spanner in the works. These logistical challenges can drive up labour and equipment hire costs for things like cranes and scaffolding.
• Fixtures and Finishes: This is a big one. Your choice of materials for flooring, windows, cabinetry, and bathroom fixtures plays a massive role. Standard, quality selections will help keep costs in check, while premium, imported finishes will naturally elevate the final price.

To give you a clearer picture, we've broken down the potential costs for a second story addition in the Murrumbeena area into a few common project tiers.

Estimated Cost Ranges for Murrumbeena Second Story Additions

This table illustrates how the budget scales with your vision. A standard build offers fantastic value and space, while a premium build allows for complete customisation and high-end luxury.

In Australia, adding a second storey has become a major financial undertaking. As of early 2025, the typical starting cost for a project like this is around $450,000 AUD, with more intricate designs easily pushing between $500,000 and $750,000 AUD. This variance is heavily influenced by the home's existing structure and its location, with metropolitan areas like those across Victoria seeing very similar price points. To dig deeper, you can explore more detailed second-floor addition cost breakdowns to better understand these figures.

The best way to find out what the cost would be is to have an initial concept drawing developed. These plans can then be estimated by an experienced home extension builder like Envy Abode to determine an accurate cost.

 

Why Per Square Metre Rates Are Deceiving

When you start exploring the cost to build a second story, you’ll quickly come across builders quoting a "per square metre" rate. On the surface, it seems like a simple, honest way to compare quotes and figure out your budget. But for a second storey addition, that number can be incredibly misleading.

Relying on a square metre rate alone is like trying to guess the cost of a gourmet meal by looking at the price of flour. It completely misses the complex techniques, specialised equipment, and premium ingredients that actually create the final dish. A second storey addition is a world away from a simple ground-floor extension, and a basic rate just doesn’t capture that reality.

Beyond the Basic Rate

A per square metre price usually only covers the new bits you can see—the walls, floors, and roof of the added space. What it rarely includes is all the intensive, foundational work needed to build upwards safely and legally. This is where the real costs are hiding.

Think about all the essential work that a basic rate glosses over:

• Structural Engineering: First things first, an engineer has to figure out if your existing ground floor can even handle the immense weight of a whole new level. This often means strengthening foundations and reinforcing load-bearing walls.
• Site Logistics: Getting materials up to a second level isn't as simple as carrying them through the front door. It requires expensive equipment like cranes to lift steel beams and extensive scaffolding for safe access, especially on tight Murrumbeena blocks.
• Complex Services Integration: Tying in plumbing, electrical, and HVAC systems from downstairs to a new upper level is intricate work. It’s a lot more involved than just extending a few pipes and wires.

These are just a handful of the critical steps that make building up such a specialised process. For a deeper dive into how these factors are calculated, check out our guide on building costs per square metre, which breaks down the nuances often left out of simple estimates.

The True Cost Drivers

The sheer structural complexity of second-storey additions in Australia is what really drives up the final price. Industry benchmarks for 2025 put the average rates between $5,500 and $8,500 AUD per square metre—a significant jump compared to ground-floor extensions.

This premium is a direct result of all the necessary engineering, scaffolding, crane hire, and major modifications to your existing home's structure.

There is no one-size-fits-all price. Second storeys are custom-built and totally unique to the existing home, so a generic rate can never account for your property's specific challenges and your project's design.

Think of it this way: two additions of the exact same size could have wildly different costs. One might be a simple rectangular box on a home with a modern, solid foundation. The other could be a complex architectural design with multiple angles, built on an older Murrumbeena home that needs serious structural upgrades before you can even start.

Getting an Accurate Estimate

The only way to know the real cost is to forget the generic formulas. The process demands a detailed, on-site assessment of your specific situation. Every home has its own history, structural integrity, and unique challenges that have to be professionally evaluated.

Because of this, the most reliable way to determine the cost to build a second story is to get initial concept drawings done by a designer or architect. These plans give a clear blueprint of your vision. From there, an experienced home extension builder, like the team here at Envy Abode, can use those drawings to conduct a thorough analysis and provide an accurate, itemised estimate.

This professional approach ensures there are no nasty surprises down the track and that your budget is based on reality, not a deceptive square metre guess.

The Five Core Drivers of Your Project Cost

Figuring out the final cost to build a second story isn't about finding a single magic number. It's about understanding the key ingredients that make up the total price. While every home is different, our experience shows there are five core factors that consistently have the biggest impact on the budget. When you break these down, you can see exactly where your money is going and why a detailed quote is so important.

This chart gives you a pretty typical look at how the funds for a second-storey addition get split up.

As you can see, materials eat up the biggest slice of the pie. This really drives home how much your design choices and finishes will shape the final investment.

1. Your Home's Existing Structure

Before we even think about framing a new wall, we have to answer the most critical question of all: can your current house actually support the weight of a whole new level? This is square one for any second-storey addition and a huge variable in the cost. Your home’s foundation and ground-floor frame are the shoulders that will carry the new structure, and they need to be strong enough for the job.

Getting a structural engineer to assess your property isn't optional—it's essential. They'll dive deep into your home's footings, load-bearing walls, and overall integrity. A lot of the charming older homes you see around Murrumbeena, for instance, were simply never built to hold up an extra storey.

If the engineer says we need to beef things up, that could mean:

• Underpinning the Foundation: Adding extra concrete or steel piers to strengthen the existing footings.
• Adding Structural Beams: Sliding new steel beams across the ground-floor ceiling to help spread the new load.
• Reinforcing Walls: Bolstering the timber or brick walls to make sure they don't shift or crack under the pressure.

These upgrades are a serious cost, but they’re absolutely vital for the safety and long-term health of your home. It’s worth taking a moment to understand what is structural engineering and the crucial role it plays in a successful project.

2. Design Complexity and Size

Okay, this one might seem obvious. A bigger addition costs more. But it's not just about square metres; the complexity of the design is just as important. A simple, rectangular "box" built on top of your existing footprint will always be a more budget-friendly option than a highly detailed architectural design.

Think of it this way. A straightforward layout with standard ceilings requires less specialised work and materials. But the moment your vision includes features like soaring vaulted ceilings, a roof with multiple gables, a cantilevered balcony, or a unique floor plan, the costs start climbing. Every unusual angle, curve, or architectural flourish adds a layer of complexity to the engineering, framing, and finishing work.

Every design choice creates a ripple effect on the budget. That larger window might need a different structural beam, while a complex roofline requires more intricate framing and waterproofing. This is exactly why a detailed design phase is so critical for getting an accurate cost projection.

 

3. Quality of Finishes and Fixtures

This is where you really get to sit in the driver's seat of your budget. The fixtures and fittings you select can make the final cost to build a second story swing wildly in either direction. There’s a massive price gap between standard, builder-grade materials and premium, high-end selections.

Just think about the difference across a few key areas:

• Windows: Standard aluminium-framed windows are far more affordable than custom-made timber or high-performance thermally broken windows.
• Flooring: Good quality carpet or laminate is a great budget-conscious choice, while solid hardwood timber or imported tiles represent a much bigger slice of the budget.
• Bathrooms: You can create a perfectly functional bathroom with standard tiles, a basic vanity, and chrome taps. Or, you can design a luxury ensuite with floor-to-ceiling marble, a freestanding tub, and designer fixtures—for a fraction of the cost.
• Cabinetry: Custom-built joinery for wardrobes and storage will be a world away in price from quality flat-pack or modular solutions.

It often helps to create a "good, better, best" list for your finishes. This lets you decide where you want to splurge and where you’re happy to save.

4. Site Access and Logistics

The simple reality of building on your specific block—especially in established suburbs like Murrumbeena—is a huge cost driver that often gets overlooked. Unlike building on a clean, vacant lot, we’re working around your existing home, your neighbours, and often, very tight spaces.

These logistical hurdles can add significant costs, including:

• Crane Hire: We need a crane to lift heavy materials like steel beams, roof trusses, and wall frames over your home. That’s a substantial expense.
• Scaffolding: To keep our team safe and provide proper access, we need extensive scaffolding, which is a major line item on any quote.
• Traffic Management: If you’re on a narrow street, we might need traffic control for big deliveries or when the crane is operating, adding another layer of cost and complexity.
• Material Storage: Limited space on-site might mean we need more frequent, smaller deliveries, which bumps up the transport costs.

This is a key reason why those generic 'per square metre' rates you see online can be so misleading. They don't account for the real-world costs of reinforcing a foundation or hiring a crane to navigate a tight suburban street.

5. Ground Floor Modifications

Finally, you have to remember that adding a second storey isn't just about what's happening upstairs. The new level has to connect seamlessly with the old one, and that almost always means making changes to your ground floor.

The most obvious change is the new staircase. Finding the space for it often means sacrificing part of an existing room, which might then need to be reconfigured. Beyond that, we need to run all the new plumbing, electrical wiring, and air conditioning ducting from the ground floor up to the new level. This can involve cutting into existing walls and ceilings, all of which adds labour and material costs that are essential to making the two levels feel like one cohesive home.

Uncovering the Hidden Costs in Your Budget

A builder's quote is a massive piece of the financial puzzle, but it’s crucial to remember it’s not the whole picture. The number on that document covers the direct construction work, but a successful second storey addition involves several other essential expenses that often catch homeowners by surprise.

Thinking about these costs upfront is the key to creating a truly realistic budget and avoiding a lot of stress down the line.

These aren't "hidden" costs because builders are being tricky; they're simply professional services and external fees that fall outside the main construction contract. Getting a clear handle on these is a vital step in planning the true cost to build a second storey for your Murrumbeena home.

Professional and Council Fees

Before a single nail is hammered or a wall comes down, a surprising amount of professional groundwork needs to happen. These initial steps are all about making sure your project is safe, compliant, and well-planned from the get-go.

• Architectural and Engineering Fees: An architect or designer is the one who translates your vision into detailed, buildable plans. Then, a structural engineer comes in to do the calculations and ensure your existing home can safely support the weight of a whole new level. These fees are foundational to everything that follows.
• Council Permits and Reports: Every build needs council approval. This means lodging your plans, which comes with application fees. You may also need specific reports, like soil testing, to satisfy their requirements. Figuring out how to get a building permit is a critical part of this early stage.
• Asbestos Testing and Removal: A lot of older homes in Murrumbeena contain asbestos. If your renovation is going to disturb any of it, you're legally required to have a licensed professional test for it and safely remove it. This can be a significant and often unforeseen expense.

Lifestyle and Finishing Costs

Beyond the physical structure, you need to think about the practical and aesthetic elements that make the project liveable—both during and after the build. These costs are highly personal but are just as real as concrete and timber.

Your project doesn’t end the day the builders leave. Factoring in costs for temporary accommodation and post-construction repairs ensures a smoother transition back into your newly expanded home.

Don't forget to add these to your budget:

• Temporary Accommodation: Adding a second storey is seriously disruptive. It’s almost certain you’ll need to move out for a good chunk of the build. Renting a property for several months is a major cost that absolutely must be included in your overall budget.
• Landscaping Repairs: Construction sites are tough on gardens. Heavy machinery, scaffolding, and stacks of materials can wreak havoc on your lawn, garden beds, and paths. It’s wise to set aside some funds to repair and restore your landscaping once the dust settles.

The Essential Contingency Fund

No matter how meticulously you plan, unexpected issues are just part of the deal with major renovations. A contingency fund isn't an optional extra; it's an essential safety net that protects your project from delays and financial strain.

Most experienced builders recommend setting aside 10-15% of your total construction cost for this fund. This buffer is there to cover unforeseen problems, like discovering hidden structural issues, hitting unexpected site challenges, or even just deciding on a small upgrade mid-project.

Having this money in place provides peace of mind and ensures you can handle bumps in the road without derailing your entire vision. Without it, you risk having to make tough compromises on quality or scope later on.

Right, you've sifted through all the variables—from structural engineering to kitchen tapware—and now you want to swap those ballpark figures for a real, hard number. So, how do you figure out the actual cost of building your second story?

The honest truth is you won't find it on a blog post or an online calculator. The final price tag only comes to light after a detailed, professional process that’s completely tailored to your home, your block, and your vision.

There’s no one-size-fits-all formula here. Every second-story addition is a custom job, uniquely shaped by the house it sits on. The only reliable way forward is to follow a few clear, actionable steps that turn your dream into a buildable—and budgetable—reality. This journey makes sure every kilo of new weight, every design choice, and every logistical headache is sorted before a single hammer is swung, saving you from nasty surprises down the track.

Start with a Clear Vision

The first step has nothing to do with builders or blueprints. It starts with you and your family. Before you even think about calling in the pros, sit down and get a crystal-clear idea of what you need and want from the new space. This isn’t about technical drawings; it’s about how you want to live.

Ask yourselves a few key questions to build a solid brief:

• What’s the main goal? Are you adding bedrooms for a growing family, carving out a parent's retreat, or building a dedicated work-from-home space?
• What are the must-haves? Pinpoint the non-negotiables, like the exact number of bedrooms and bathrooms you absolutely need.
• What are the "would be nice" features? Think about the extras, like a walk-in wardrobe, a cosy study nook, or a particular window style that would just make the space.
• How will it connect to downstairs? Where’s the best spot for the staircase? Consider how its placement will affect the flow and layout of your ground floor.

Having a well-defined brief makes the whole process smoother. It means the design phase will be sharply focused on hitting your specific goals from day one.

Engage a Professional Designer

With your vision in hand, it's time to bring in an architect or a specialized building designer. Their job is to take your brief and translate it into a set of initial concept drawings. These plans are the first real, tangible picture of your new second story, showing the floor plan, elevations, and the overall look and feel.

This is a critical, collaborative phase where your ideas meet professional know-how. The designer won’t just draw boxes for rooms; they’ll consider natural light, how you'll move through the space, and how the new addition will look sitting on top of your existing home.

These initial concept drawings are the foundation of your entire project. They aren't just sketches—they're the blueprint a builder uses to perform a detailed cost analysis, turning your ideas into a project with a tangible scope and a real-world budget.

 

Partner with an Experienced Local Builder

Once you have your concept drawings, it’s time to find an experienced home extension builder who specialises in the Murrumbeena area. A local expert brings invaluable knowledge of the area's typical housing styles, council regulations, and site-specific challenges.

You’ll give them the drawings to get a detailed estimate. Unlike a simple square metre guess, this will be a comprehensive breakdown based on your unique design. An expert builder will use those plans to accurately assess:

• The required structural engineering work.
• The quantity and quality of all materials needed.
• The labour involved in every single stage of construction.
• Logistical costs, like site access and crane hire.

This detailed, bottom-up approach is the only way to find out what your project will truly cost. A specialist firm like Envy Abode can provide an accurate, itemised quote based on professional concept drawings, giving you a clear financial roadmap. For an idea of what goes into an estimate, you can review this helpful extension cost estimator to see how all the different parts contribute to the total. This professional process is the only way to get a figure you can actually rely on.

Answering Your Top Second Story Questions

When you start thinking about adding a second storey, the questions come thick and fast. Once you get past the initial sticker shock, homeowners in Murrumbeena want to know about the nuts and bolts of a project this big. We’ve pulled together the most common queries to give you clear, straightforward answers so you can plan your addition with confidence.

Getting your head around these details gives you a much better picture of the entire journey, from the first napkin sketch to the final coat of paint. It’s about more than just the budget—it’s about making smart decisions for your home and your family.

Will My Home's Foundation Support a Second Story?

This is the big one. It’s hands down the most critical question and the very first thing you need a professional to answer. The short version is: maybe, but you can't assume it will. Many homes, especially older ones, were built with foundations only ever meant to hold up a single level.

Before a single plan is drawn, you must bring in a structural engineer. They’ll assess your existing foundation, footings, and ground-floor structure to figure out if it can handle the enormous extra weight. If it can’t, you’ll be looking at reinforcements like steel beams or foundation underpinning, which will absolutely have a major impact on the final cost to build a second story.

How Long Does It Take to Add a Second Story?

A project of this scale is a marathon, not a sprint, so patience is a virtue. Realistically, you should block out anywhere from 8 to 12 months for the entire process from start to finish.

This timeline breaks down into a few key phases:

1. Design and Planning: This is where it all begins. Developing concepts, finalizing architectural drawings, and getting all the engineering sorted can easily take 3 to 4 months on its own.
2. Permitting: Submitting plans to the local council and waiting for the green light is a process with its own timeline, often adding several more weeks or even months.
3. Construction: Once the permits are approved and the crew is on-site, the physical build typically takes another 6 to 8 months, though this can be affected by the project’s complexity, weather delays, and material availability.

Do I Have to Move Out During Construction?

In almost every single case, the answer is yes. Adding a second storey is one of the most disruptive renovations you can possibly do. The process literally involves taking the roof off your house, leaving it wide open to the elements for a while.

On top of that, you'll have major structural work happening on the ground floor, not to mention the constant noise, dust, and disruptions to essentials like water and electricity. It just isn't practical or safe to live there. Factoring the cost of temporary accommodation into your budget isn't just a good idea—it's a must.

Plan for several months of rent for a temporary home. It’s a crucial part of your budget that ensures your family stays comfortable and safe while allowing the construction team to work efficiently without any hold-ups.

 

Is It Cheaper to Build Up or Build Out?

This is a classic dilemma for homeowners who need more room. While every project has its own quirks, it's generally less expensive to build a ground-floor extension ("building out") than it is to add a second storey ("building up").

Building out sidesteps the complicated and pricey engineering needed to reinforce an existing structure for another level. It also means you don't need to hire expensive cranes or put up massive scaffolding. The trade-off, of course, is that you sacrifice your precious yard space, which isn't always an option on smaller Murrumbeena blocks. Building up protects your outdoor area and often delivers better views and more natural light.

Will Adding a Second Story Increase My Home's Value?

Absolutely. In most markets, a well-designed and properly built second storey adds significant value to a home. You’re adding a huge amount of square footage, often with highly sought-after features like extra bedrooms and bathrooms. This directly boosts your property's market appeal and resale price.

The return on investment (ROI) can vary, but a thoughtful addition that feels like a natural part of the original home can provide a fantastic financial return. It turns a smaller house into a spacious family home—a hot commodity in suburbs like Murrumbeena. A quick chat with a local real estate agent can give you specific insights into how much value an addition could bring in your neighbourhood.

Ready to transform your Murrumbeena home with a beautifully designed second story? The journey from concept to completion requires expertise, vision, and meticulous attention to detail. At Envy Abode, we specialise in creating seamless, luxury home extensions that perfectly align with your family's needs and your home's unique character.

Discover how our integrated design-build process can bring your vision to life by visiting Envy Abode.