House Extension Cost Sydney 2025 – Get Your Free Guide Here
Calculate your house extension cost Sydney for 2025 with our simple guide below.
Is your family outgrowing your current home? Whether you’ve welcomed a new bundle of joy, need a home office or want to accommodate extended family, the reasons for needing more space are endless.
When it’s time to expand, you typically have two choices:
- move to a bigger house, or
- extend your existing one
to meet your family’s needs.
Why Choose a House Extension?
If your current home is in a convenient location—close to work, schools, and the amenities you love—extending it might be the better option. In essence, depending on your property, you can:
- Extend outward into the backyard, or
- Build upward by adding a second storey.
But how much does it cost to add space to your home? Let’s break it down so you can budget effectively.
Overview of House Extension Cost Sydney
Use the table below as a guide to calculate your house extension cost Sydney. Start by deciding whether to expand outwards or upwards, then calculate the area you wish to extend. Most importantly, if you’re adding a kitchen or bathroom, include those costs too.
| Price per additional sqm | Add for kitchen | Add for each bathroom | |
|---|---|---|---|
| Ground Floor Extension | $2,400 – $2,900 | $45,000 – $80,000 | $35,000 – $50,000 |
| First Floor Addition | $3,800 – $4,200 | $45,000 – $80,000 | $35,000 – $50,000 |
This information is to be used as a guide only. The prices apply to Sydney NSW. Most importantly, all costs include GST.
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Ground Floor Extension Cost
For a brick veneer ground floor extension, costs range from $2,400 to $2,900 per m². Above all, this depends on factors like:
- Foundation requirements
- Size (smaller extensions have a higher cost per m²)
- Site access and terrain (sloping or flat)
- Building materials
Extension Cost for Adding a Second Storey
If expanding outward isn’t an option, consider building up. However, adding a second storey typically costs more, ranging from $3,800 to $4,200 per m². Reasons include:
- Replacing the roof and constructing a new one
- Reinforcing ground floor walls to bear additional weight
- Installing a staircase
Additional Costs to Consider
Add cost for new kitchen
Adding a standard, good-quality kitchen will cost $45,000 to $80,000 for cabinetry and benchtops. Appliances such as ovens, cooktops, and dishwashers are extra. Though luxurious finishes can quickly push costs beyond $110,000.
Add cost for new bathrooms
Bathrooms are labour-intensive, costing $35,000 to $50,000 each. As a result, most of the expense comes from labour (tiling, waterproofing, plumbing), with a smaller portion for materials like tiles, vanities and shower screens.
Cost Examples
Here’s what you might expect for your house extension cost Sydney for common scenarios:
Ground Floor Extension (120m², with 1 bathroom and 1 kitchen):
- Total Cost: $368,000 to $478,000
Second Storey Addition (120m², with 2 bathrooms):
- Total Cost: $526,000 to $604,000
Inclusions in the Costs
Both vertical and horizontal extensions typically include:
- Demolition and excavation
- Timber framing, bricks and roofing
- Windows, doors and flooring
- Plumbing and electrical work
- Insulation
Additionally, the costs assume a quality builder who is a member of either the Housing Industry Association (HIA) or the Master Builders Association (MBA). Not only indicate these memberships proven expertise but ongoing professional development, too.
Other Expenses to Budget For Your Home Extension
Design and Approvals Affect Your House Extension Cost
Include fees for building designers, interior designers, surveyors, engineers and council approvals. Allow for $40,000 to $90,000.
Incorporate Insurance into Your House Extension Cost Sydney
The Home Building Compensation Fund (HBCF) premium ranges from $3,000 to $6,000 for ground-floor projects, offering a safety net if your builder becomes insolvent.
Contingency Planning for Your House Extension Cost
Always set aside a contingency budget of approx. 20% to your house extension cost Sydney. The reason is to cover unforeseen expenses because renovating existing structures often reveals surprises that require extra work.
Return on Investment of your House Extension Cost
While extending your home requires a significant investment, Sydney’s property market offers strong potential for a high return. After all, a well-planned, quality extension can enhance your home’s value while giving your family the space and comfort they deserve.
But the true value lies in the joy of creating a home that fits your lifestyle. After all, you can’t put a price on family happiness!
Guide to Renovation Planning
If you don’t know where to start your home extension project, get our simple 10-step guide that will lead you through the renovation planning process. You can download this guide by submitting your name and email address.
Ready to Get Started with Your House Extension?
If you’re considering a home extension, reach out to Martina Hayes for guidance. With over 10 years of experience in interior design and building design, Martina can help you navigate the process and plan your next steps.
Contact her at martina@martinahayes.com.au or 0434 498 450.
