If you are planning a new build in Sydney, the single biggest variable in your timeline — outside of weather — is which approval pathway you take. Get it right and you could be on site in a matter of weeks. Get it wrong and you could spend a year and tens of thousands of dollars on consultant reports before a single brick is laid.
The two paths are a Complying Development Certificate (CDC) and a Development Application (DA). They are fundamentally different processes with different rules, timelines, costs, and risks. Here is what you need to know to make the right call for your project.
What Is a CDC?
A Complying Development Certificate is a fast-track approval pathway where your project is assessed against a set of pre-determined, state-wide standards — known as the State Environmental Planning Policy (SEPP) — rather than being judged on its merits by your local council. If your design ticks every box, approval is effectively automatic. There is no public notification period, no neighbour objections, and no council politics.
CDCs are assessed by private certifiers (also called Accredited Certifiers or Principal Certifying Authorities), not by council planners. This is the key reason they are faster: private certifiers compete on speed and service; council planners do not.
What Is a DA?
A Development Application is the traditional council approval process. Your project is assessed against the local council's Development Control Plan (DCP) and Local Environmental Plan (LEP) — which vary from one LGA to the next. The assessment considers not just numerical standards but also character, streetscape, heritage, view corridors, and neighbour impact. There is a public notification period where neighbours can make submissions. A council planner makes a subjective decision about whether your project should proceed.
Side-by-Side Comparison
| Factor | CDC | DA |
|---|---|---|
| Typical timeline | 2–6 weeks | 3–12 months |
| Assessment by | Private certifier | Council planner |
| Public notification | No | Yes (14–28 days) |
| Neighbour objections | Cannot block approval | Can delay or derail |
| Design flexibility | Must meet strict numerical standards | Can argue merit on non-compliant items |
| Cost (approvals & consultants) | $3,000–$8,000 | $8,000–$25,000+ |
| Council fees & contributions (both paths) | Allow ~$35,000 for council fees, s7.11/s73 contributions and the NSW Housing & Productivity Contribution — see our cost calculator | |
| Best for | Straightforward builds on compliant blocks | Complex sites, heritage areas, non-standard designs |
When a CDC Works (And When It Doesn't)
For most knock down rebuilds and custom homes on standard suburban blocks in Sydney, a CDC is the preferred path — here is what a KDR costs — if your design fits within the numerical standards. The key standards under the Housing SEPP for a single dwelling include:
- Height: maximum 8.5m (single storey typically not an issue; two-storey needs careful design)
- Floor Space Ratio (FSR): varies by LGA but typically 0.5:1 for R2 zones
- Setbacks: minimum 4.5m front, 0.9m side, 3m rear (varies slightly by block size)
- Site coverage: maximum 50% of block area covered by buildings
- Landscaped area: minimum 25% of block as soft landscaping
If your design exceeds any of these — for example, you want a taller ceiling height that pushes the overall height to 8.8m, or your block is slightly too narrow for the side setback requirement — you cannot use a CDC. Even a 100mm breach kills it. In that case, you must go through a DA and argue the merits of your design to council.
Some builders will tell you "we'll do it under CDC" to make the timeline sound fast — only to discover during detailed design that your block or brief does not comply with SEPP standards. You then lose weeks redesigning or get pushed onto the DA path with no time saved. A good builder checks CDC compliance at the first site assessment, not after you have signed a contract.
When a DA Is Unavoidable
In certain situations, you do not have a choice — a DA is mandatory. These include:
- Heritage conservation areas: if your property is within a Heritage Conservation Area (HCA) or the existing dwelling is heritage-listed, a DA is required — and expect additional heritage impact statements.
- Bushfire-prone land: if your block is mapped as bushfire-prone (BAL-12.5 or higher), you cannot use a CDC and must do a DA with a bushfire assessment report.
- Flood-prone land: properties within flood planning areas in councils like Fairfield, Canterbury-Bankstown, and parts of the Hawkesbury require a DA with flood studies.
- Non-standard designs: if you want a design that deliberately exceeds SEPP standards — more height, less setback, higher site coverage — a DA is your only path.
- Subdivision: any proposal to subdivide land (including torrens title subdivision of a duplex) requires a DA.
Which Sydney Councils Are Fastest (and Slowest)?
DA processing times vary dramatically by council. Based on our experience and published council data, here is the rough landscape in 2026:
- Faster councils (2–4 months typical): Fairfield, Liverpool, Penrith, Campbelltown, Blacktown — these LGAs tend to have higher volumes and more streamlined processes.
- Moderate councils (3–6 months typical): Parramatta, Canterbury-Bankstown, The Hills, Sutherland — solid but can be slowed by complex DCP requirements.
- Slower councils (6–12+ months typical): Inner West, North Sydney, Lane Cove, Ku-ring-gai, Woollahra, Mosman — these councils have detailed heritage, character, and design controls that add layers of assessment.
Note: these are estimates for a complete, well-prepared DA with all required reports. A poorly prepared application can double any of these timelines regardless of council.
Which Path Should You Choose?
If your block and brief allow a CDC, take it. The time, cost, and certainty advantages are significant — and you avoid the single biggest risk in any DA: a neighbour objection that triggers a council review and months of delay. A CDC is objective; a DA is subjective.
If your project requires a DA, do not cut corners on the application quality. Engage a good town planner early, commission all required reports upfront, and prepare a strong Statement of Environmental Effects. The money you spend on a well-prepared DA is a fraction of what you lose in holding costs if a cheap application gets rejected and you have to resubmit.
At Kadmia Constructions, we assess CDC eligibility at the very first site visit — before any design work begins. If a CDC is possible, we design within the standards from day one. If a DA is required, we manage the entire process through our five-stage methodology so you do not have to navigate council alone.