What does it cost to build a house in Sydney?
A custom home in Sydney costs between $4,500 and $7,000 per square metre of internal area in 2026. That range is wide enough to be almost useless for planning. The real question isn't the per-sqm number. It's what that number includes, and whether your builder can stand behind it in a signed fixed-price contract.
Book a discovery callThree reasons the headline number is almost never the real number.
1. Site costs vary from $30,000 to $100,000 or more
Excavation, service connection, and retaining vary enormously between blocks. A flat cleared inner-west block and a sloping North Shore site can carry $70,000 of difference in site costs alone.
2. Inclusions lists differ dramatically
One builder's $5,500/sqm may exclude what another builder includes. Without a like-for-like inclusions list, you are not comparing the same thing.
3. Allowances mask cost blow-outs
Allowances are placeholder numbers for kitchens, bathrooms and tiling that make quotes look lower than the final cost. They are the single biggest source of cost blow-outs in Sydney custom home builds.
The site costs that move the number most.
Two identical homes on two different blocks can be tens of thousands apart before a wall goes up. These are the site-specific drivers behind that gap, worth understanding before you commit to a block or a headline price. They are also why a real number needs your actual site, not an average.
A flat, cleared block is the cheap baseline. As the land falls, you pay for cut and fill, retaining walls, and often a split-level design or a drop-edge slab. A steep site can add tens of thousands before the house itself begins.
The soil report sets how the foundation is built. Reactive clay or rock means deeper piers or rock excavation, priced from an educated assumption and confirmed on site. We agree pier rates up front, so a depth change adjusts fairly rather than inflating the contract.
Where council requires it, an OSD tank holds stormwater and releases it slowly. Its size scales with your roof and paved area and the drainage downstream, so on a tight or downhill block it becomes a genuine line item, not a rounding error.
On a knockdown rebuild, removing the existing home, disconnecting services and clearing the block is its own cost. Where asbestos is present, it is handled under strict rules and adds to the figure.
Connecting or upgrading services depends on what already sits at the boundary. A long run, a capacity upgrade, or relocating a sewer line that crosses the block can move the number significantly.
A narrow frontage, a corner block, or no room to store materials changes how trades work and what machinery fits. Tight access quietly lifts both labour and logistics costs.
Cost to build, Sydney, 2026.
| House size | Standard custom | Architect-designed | Certified Passive House |
|---|---|---|---|
| 200 sqm | $700k to $1.0M | $900k to $1.3M | $1.2M to $1.6M |
| 250 sqm | $875k to $1.3M | $1.1M to $1.6M | $1.5M to $2.0M |
| 300 sqm | $1.05M to $1.6M | $1.4M to $2.0M | $1.8M to $2.4M |
Line-item fixed-price, not guesswork.
Marvel's fixed-price contract replaces per-sqm guessing with a line-by-line cost built around your specific brief. No allowances. Variations during construction are client-initiated only, with signed change requests. Verify any builder's licence before signing a contract at NSW Fair Trading.
That transparency requires a paid pre-construction phase, but the result is a number the builder and the client both trust. If you are comparing a rebuild against a certified Passivhaus spec, the Passive House cost in Sydney page has the specific bands.
If these three things are true, we should talk.
- You have a block, or are imminently purchasing one.
- Your budget allows $900k+ construction cost.
- You value process certainty over the cheapest headline number.
Don't engage volume builders if you want transparency. Their business model requires per-sqm averages.
Frequently asked
- $4,500 to $7,000 per sqm of internal area for custom. Volume project homes can be lower but are not comparable on quality or inclusions.
Book a discovery call.
30 minutes with Mo. We'll talk through your brief, budget and block, and tell you honestly whether a Marvel build is the right fit. No sales pitch.