The short answer: a custom home in Sydney takes 18 to 24 months end-to-end from the first conversation to handover. That breaks down as 3–5 months design and documentation, 3–6 months approvals (CDC is faster than DA), 1–2 months pre-construction, and 10–14 months construction (single-storey) or 14–18 months (double-storey). A knockdown rebuild adds 3–4 weeks for demolition.
Most of the time isn't the build itself — and the design and approvals phases are where most timelines slip if the project hasn't been properly scoped early.
When clients ask us "how long?", the honest answer for a custom home in Sydney is 18 to 24 months from the day we first meet. That includes design, approvals, and construction.
Some of that time is the build itself. A lot of it isn't — and the parts that aren't are where most timelines slip.
The four phases
1. Design and documentation — 3 to 5 months. The conversation, the brief, concept design, design development, then detailed documentation good enough to actually quote and build from. This is where decisions are cheap. We resist rushing it.
2. Approvals — 3 to 6 months. A Complying Development Certificate (CDC) under the NSW Housing Code is fast — typically 10–20 business days — but only if the design fits the strict envelope, setback, and lot rules. Heritage, flood, bushfire-prone, or unusual lots usually force a Development Application (DA), which means a council assessment that runs 3–6 months in Hills Shire, Blacktown, or Hawkesbury LGAs.
A good designer flags the CDC-vs-DA call early. Discovering it late is one of the most common reasons projects fall behind.
3. Pre-construction — 1 to 2 months. Soil classification, structural engineering, sign-off on selections, the construction certificate, and site setup. None of it is glamorous, all of it is necessary for a genuine fixed price.
4. Construction — 10 to 14 months. A single-storey custom home typically runs 10 to 14 months on site. Two-storey runs 14 to 18 months. Knockdown rebuilds add 3–4 weeks for demolition and asbestos handling.
Where time gets lost
In our experience, three culprits account for most of the slippage we see in other builders' programs:
- Selections made late. Bespoke joinery, imported tapware, engineered windows and stone run 10–16 week lead times. If you're still choosing tiles in month seven on site, the program is already at risk.
- Variations during construction. Each one is a redesign, an order, and often a re-coordination of trades. Worth doing in early design, expensive once the slab is down.
- Overcommitted builders. A team running too many projects can't give yours the attention required when something needs solving in 48 hours.
That last point is why we deliberately cap how many homes we build each year.
What a realistic schedule looks like
For a 280m² single-storey custom home in Box Hill on a Class M site, no major heritage or flood overlay, CDC eligible:
- Months 1–4: design and documentation
- Months 5–7: CDC, construction certificate, pre-start
- Months 8–18: construction
- Month 19: handover
About 18 months end-to-end. Add 4–6 months for a two-storey, add 4–8 months if a DA replaces the CDC. That's the realistic shape.
How to start
The single most useful thing you can do is start the conversation early — even six months before you want to break ground. It gives us room to design well, lock selections, and get through council without anyone having to compromise.
When you're ready, walk through our build journey or get in touch. We'll be straight with you about what's possible inside your timeline.
