How much does it cost to build in Sydney in 2026?
Build cost per square metre in Sydney metro for 2025–26 ranges widely depending on the type of dwelling, the level of finish, and the difficulty of the site. Our build cost calculator uses the following base rates (per square metre of gross floor area), with site-difficulty multipliers applied on top:
| Quality tier | Duplex / Townhouse | Apartment | Renovation |
|---|---|---|---|
| Budget | $2,300–$3,000/m² | $2,800–$3,600/m² | $2,500–$3,600/m² |
| Standard | $2,600–$3,400/m² | $3,200–$4,100/m² | $3,000–$4,200/m² |
| Medium | $2,900–$3,900/m² | $3,600–$4,700/m² | $3,600–$5,000/m² |
| High-end | $3,400–$5,500/m² | $4,300–$6,500/m² | $4,200–$6,800/m² |
| Luxury | $6,000–$11,000/m² | $6,500–$12,000/m² | $6,500–$13,000/m² |
| Ultra-luxury | $9,500–$18,000/m² | $11,000–$18,000/m² | $10,000–$20,000/m² |
These rates are contract value figures — they include the builder's overhead and margin (when you sign a fixed-price contract). On a cost-plus contract you'd add a separate 15–25% margin line. They don't include land, stamp duty, council contributions, finance, HBCF, the architect, structural engineer, or contingency — all of which the calculator above adds for you.
What does a knock-down rebuild cost in Sydney?
A knock-down rebuild is costed differently from a purchase, and the difference is mostly in your favour. You already own the land, so there is no acquisition stamp duty — the single largest one-off cost in a normal buy. What you add instead is demolition and the disconnection of existing services. The rest is an ordinary build: $/m² × floor area, plus the soft costs.
Select PPR (owner-occupier) → Knock-down rebuild in the calculator above and it switches to that model. Instead of asking for a purchase price it asks what your current home is worth and what you still owe, then works out the releasable equity — conventionally 80% of the current value less the outstanding mortgage — and treats that as your contribution. From there it returns the loan required against the completed value, LVR, LMI if you cross 80%, monthly repayments, your debt-to-income ratio, and a serviceability verdict against a conservative cap.
Two numbers decide most rebuilds. The first is releasable equity versus the build cost — if the equity is thin you will be funding the gap in cash, and the calculator shows that shortfall explicitly rather than burying it. The second is serviceability: rebuilding raises the loan against a higher completed value, so repayments rise even though you have not moved. A DTI above 6.0 is the regulator's hot zone and the tool flags it.
If you are weighing a rebuild against renovating instead, the renovation mode applies a crossover test: once the build cost passes roughly half the post-renovation value, demolishing and building new is often cheaper and produces a more sellable house. Run both and compare.
What's included in build costs (and what's commonly missed)?
The biggest reason people get blindsided by their final build number isn't that their $/m² rate was wrong — it's that they forgot half the line items. PropDEV models every one of these:
- Construction — $/m² × GFA, with site-difficulty multiplier
- Builder margin — already in the rate on fixed-price; explicit 18% on cost-plus
- HBCF premium — NSW Home Building Compensation Fund (~0.7% of contract on residential builds > $20k)
- Architect & consultants — 4–12% of construction (architect, structural, civil, hydraulic, certifier, surveyor, energy, geotech)
- Professional fees — PM, DM, QS, accountant, insurance, body corp setup, strata legal (2–7.5% of construction)
- NSW DBP compliance — registered Design + Building Practitioners, regulated design declarations (~$45–120k on Class 2 builds)
- Council DA + s7.11 / s7.12 contributions — wildly variable, $8k–$75k per dwelling
- NSW stamp duty — 2025–26 schedule, premium band over $3.721M
- NSW land tax — 1.6% per year above $1.075M, 2% above $6.571M (almost no one knows this)
- Council rates — broken out as its own line ($1.5–4.5k/year Sydney metro)
- Buyer's agent fee — 1.5–2.5% of purchase or $15–40k fixed (if engaged)
- Finance — interest, line fees, establishment, capitalised onto the loan
- Marketing & selling — agent commission ~2.2% of GRV, marketing ~1.2% of GRV, legals
- GST under the margin scheme — 1/11 of (sale price − acquisition cost)
- Contingency & realism buffer — 3.5–10% by project stage plus an overrun buffer for things you priced that slipped anyway
NSW land tax — the silent line item
Many homeowners and developers don't realise NSW charges land tax annually on any land you own that isn't your principal place of residence — including development sites that are sitting waiting for DA approval or construction. The FY2025–26 schedule:
- Land value ≤ $1,075,000 — no land tax payable.
- Land value $1,075,001 – $6,571,000 — flat $100 plus 1.6% of the amount above $1,075,000.
- Land value over $6,571,000 — premium rate of 2.0% on the amount above $6,571,000, on top of the general band tax.
On a typical $3M Sydney development site that's about $31,000 per year while you hold it. On a $7M site it's about $97,000 per year. The calculator picks this up automatically from your purchase price (as a proxy for unimproved value) — toggle exempt if it's your PPR.
Class 1 vs Class 2 building — and why it matters
The National Construction Code classifies buildings into roughly ten classes. For residential developers in NSW, the two that matter are Class 1a (a single dwelling on its own title — e.g. a Torrens-titled duplex or detached house) and Class 2 (two or more sole-occupancy units sharing a building — almost every strata-titled duplex, townhouse, or apartment).
Class 2 (and Class 3 / 9c) trigger the NSW Design and Building Practitioners Act 2020: your builder must be DBP-registered, every regulated design needs a registered Design Practitioner's compliance declaration, and a Principal Design Practitioner coordinates the package. Practically that's an extra $45,000–$120,000 in fees plus 1.5–4 months of program — meaningful at duplex scale, very meaningful at townhouse scale.
The calculator's Building classification panel auto-detects Class 1a vs Class 2 based on your title type (Torrens vs strata) and yield, and adds the DBP compliance surcharge to the planning & design bucket when it applies. Override available.
Renovation cost calculator — should I add a bed & bath?
The Renovate / extend deal mode answers the homeowner question: “if I spend $X to add a bed and bath, what's my home worth after vs before — and am I better off?”
It uses the same cost engine as the developer side (construction, consultants, finance, contingency, HBCF, DBP where applicable) but the verdict is different: not “profit” but equity gain. The suburb median for the proposed bed-count config acts as your value ceiling — pushing your finished property materially above the suburb's median for that config is risky money, because buyers anchor hard to comparable sales.
