A CDC (Complying Development Certificate) is a fast-track private approval that bypasses council entirely — it takes 3 to 6 weeks and is available to most Sydney homeowners with a block of 450m² or more. A DA (Development Application) goes through council, takes 3 to 12 months or longer, and is only required when your site or design falls outside the standard CDC criteria. For the vast majority of Five Star's builds, the CDC pathway is the right choice.
If you're thinking about building a granny flat in NSW, you'll encounter two terms almost immediately: CDC and DA. Both are forms of planning approval — but they work completely differently, cost different amounts, and take very different amounts of time.
Understanding which one applies to your situation is one of the most important steps you can take before starting any design or construction conversations. It shapes your timeline, your budget, and in some cases, your design options. This guide breaks both pathways down clearly so you know exactly what to expect — and what questions to ask when you sit down with a builder.
1. What Is a CDC (Complying Development Certificate)?
A Complying Development Certificate is a type of planning approval for building work that meets pre-set state government standards. These standards are set out in the State Environmental Planning Policy (Housing) 2021 — commonly called the Housing SEPP. When your proposed granny flat meets those standards, a licensed private certifier (not your local council) reviews and approves the plans.
The key distinction: a CDC bypasses council entirely. There is no application lodged with council, no public notification period, and no opportunity for neighbours to formally object to your build. As long as you meet the SEPP criteria, the certifier issues the certificate and construction can begin.
Why homeowners prefer the CDC pathway
- Speed: The average CDC for a granny flat in NSW is approved within 3 to 6 weeks — compared to 3 to 12 months for a DA through council
- Certainty: If your design complies with the SEPP criteria, approval is essentially guaranteed. There's no discretionary decision-making, no subjective assessment by a council planner
- No neighbour objections: Because there's no public exhibition period, neighbours cannot lodge formal objections that delay or block your build
- Lower cost: Private certifier fees are generally lower than council DA application fees, and you avoid the additional costs that often come with DA specialist reports
- Simpler process: Five Star manages the entire CDC process on your behalf — you don't need to engage with any government body directly
The Housing SEPP 2021 consolidated several older policies — including the former SEPP (Affordable Rental Housing) 2009. If you've seen references to the older SEPP online, the 2021 version is the current applicable law. The core CDC eligibility criteria for granny flats remain largely unchanged.
2. What Is a DA (Development Application)?
A Development Application is a formal request to your local council for approval to carry out development. Unlike a CDC, which is assessed against fixed state-level standards, a DA is assessed by council planners against your local council's planning rules — specifically the Local Environmental Plan (LEP) and Development Control Plan (DCP).
The DA process is significantly more involved:
- Application lodgement: Plans, reports, and supporting documents are submitted to council via the NSW Planning Portal
- Public notification: Most DAs are publicly exhibited, meaning neighbours and other parties can view your plans and make formal submissions objecting to or supporting the development
- Council assessment: A council planner assesses the proposal against the LEP and DCP, considering any public submissions received
- Decision: Council can approve (with or without conditions), request amendments, or refuse the application
application submission
busy council areas
A DA is not necessarily a worse outcome — in some cases it's the only path available, and councils can approve designs that don't meet the standard CDC criteria. But you need to go in with realistic expectations. DA costs are higher, timelines are longer, and the outcome is less certain because it involves discretionary decision-making by council planners.
Some councils in NSW have historically had DA processing times of 12 months or more for residential development applications. If you're in a heritage-heavy local government area or a council under-resourced for planning assessment, factor this into your timeline expectations before committing to the DA route.
Not sure which approval applies to your block?
Our team checks your CDC eligibility as part of a free on-site assessment — no obligation, no guesswork.
3. CDC vs DA: Full Comparison Table
Here's a direct side-by-side comparison of everything that matters when choosing between the two approval pathways for your NSW granny flat:
| Factor | ✅ CDC | ⏳ DA |
|---|---|---|
| Who approves it | Private certifier — no council involvement | Local council planning department |
| Typical timeline | 3 to 6 weeks | 3 to 12 months (often longer) |
| Public notification | ✗ None — neighbours cannot object | ✓ Public exhibition period applies |
| Outcome certainty | High — if you comply, you get approved | Discretionary — council can refuse or require changes |
| Typical cost | Lower — private certifier fees only | Higher — council fees plus potential specialist reports (heritage, stormwater, traffic) |
| Design flexibility | Lower — must meet fixed SEPP criteria | Higher — council can approve non-standard designs |
| Minimum block size | 450m² (with 12m frontage) | No fixed minimum — council assesses on merit |
| Max floor area (standard) | 60m² | Can exceed 60m² if council approves |
| Good for | Standard Sydney blocks meeting SEPP criteria | Small blocks, heritage areas, flood zones, non-standard designs |
| Five Star recommendation | ✓ Preferred pathway for most builds | Used when CDC is not available for your site |
4. CDC Eligibility Criteria in NSW
Under the SEPP (Housing) 2021, your property must meet all of the following criteria to use the CDC pathway for a granny flat. All criteria must be satisfied — failing any one of them means you'll need to consider a DA instead.
- ✓Lot size: The property must be at least 450m² in total area
- ✓Street frontage: The block must have a minimum 12 metre street frontage
- ✓Floor area: The granny flat must not exceed 60m² of internal floor area
- ✓Height: Maximum 8.5 metres ridge height; maximum 3.8 metres external wall height (single storey)
- ✓Setbacks: Side and rear setbacks from property boundaries must comply with SEPP Schedule 1 requirements (these vary by wall height)
- ✓One per property: Only one granny flat is permitted per lot, and it must be ancillary to the principal dwelling
- ✓Principal dwelling type: The main home must be a freestanding house — not a villa, townhouse, flat, or unit
- ✓Zone: The property must be in a residential zone under the local LEP
for CDC pathway
floor area (CDC)
approval time
What about heritage overlays?
This is one of the most common questions we receive, particularly from homeowners in Inner West, North Shore, and older Sydney suburbs. If your property sits within a heritage conservation area, CDC may still be available in some circumstances — but it depends on your specific council's local planning rules and whether the granny flat is visible from the street. In many heritage areas, a DA is required. We check this as part of every free site assessment.
You can check whether your property is in a heritage conservation area using the NSW Planning Portal Spatial Viewer. Enter your address and look under the "Heritage" layer. If your block is flagged, it doesn't automatically mean you can't build — it just means we need to look more closely at the right approval pathway.
5. When Do You Actually Need a DA?
A DA is not the default — it's what happens when the CDC pathway isn't available. Common triggers that push a granny flat into the DA pathway include:
- !Block under 450m²: The most common reason. You may still be able to build, but it needs council assessment.
- !Heritage conservation area: Many older Sydney suburbs (Haberfield, Balmain, parts of Mosman) require DA for secondary dwellings visible from the street.
- !Flood-affected land: Properties in flood zones require a full council assessment with a flooding report.
- !Bushfire prone land: Specific Bushfire Attack Level (BAL) requirements may preclude CDC and trigger a DA.
- !Non-compliant setbacks: If your block shape makes standard setbacks impossible to achieve.
- !Design exceeds 60m²: If you want a larger secondary dwelling, only a DA can approve it.
- !Two-storey in some councils: 2-storey granny flats are sometimes CDC-eligible but certain councils apply extra LEP controls — always verify.
In some cases, a small design modification can bring a proposal back into CDC compliance and avoid the DA process entirely. This is something Five Star evaluates during the free site assessment — it's not always obvious, and having an experienced builder who knows the SEPP criteria closely can save you months.
6. What Does Approval Cost in NSW?
Approval costs vary significantly depending on the pathway and your council, but here's a general breakdown of what to expect:
| Approval Item | CDC (approx.) | DA (approx.) |
|---|---|---|
| Private certifier / application fee | $1,500 – $3,000 | $500 – $2,500 (council fee) |
| Plans and documentation | Included in Five Star's package | Included in Five Star's package |
| Heritage impact statement | Generally not required | $1,500 – $4,000+ (if in heritage area) |
| Stormwater / drainage report | Sometimes required | Often required ($800 – $2,000) |
| Total estimated approval cost | $1,500 – $3,500 | $3,000 – $10,000+ |
The figures above are general guides only. Costs vary considerably by council, certifier, and the complexity of your application. Some council DA fees are calculated as a percentage of the estimated construction cost. For a clear breakdown of approval costs specific to your site, your free Five Star site assessment is the best starting point.
Ready to confirm your approval pathway?
We visit your block, check your CDC eligibility, and give you a clear timeline and cost picture — all at no charge.
7. How Five Star Manages Your Approval
One of the most common concerns we hear from homeowners is: "Do I have to deal with the council or the certifier myself?" For the vast majority of Five Star clients, the answer is no. We handle the entire approval process as part of our end-to-end service.
Free Site Assessment
We visit your property, measure the block, check it against the SEPP criteria, and confirm whether CDC or DA applies to your situation. We also flag any site-specific issues (slope, access, heritage, flood) that could affect the approval pathway or build cost.
Design to Compliance
Our designs are engineered to meet CDC requirements from day one. We don't design something and then hope it complies — the SEPP setbacks, height limits, and floor area maximums are built into our standard design range. You choose the design that suits your block and budget; we make sure it fits.
Certifier Coordination (CDC)
For CDC builds, Five Star works with a network of trusted private certifiers across Greater Sydney. We prepare and submit the complete application package on your behalf. You don't need to source a certifier or manage the submission process yourself.
DA Support (where required)
For sites that require a DA, we prepare the application package, coordinate any required specialist reports, and liaise with council planners throughout the assessment process. We have experience working through DAs with multiple Sydney councils and know what each council looks for in a secondary dwelling application.
Construction Begins
Once approval is granted, your 14 to 16 week build timeline starts. Five Star's award-winning construction team takes over from here — you're kept informed throughout, but there's no project management burden on you.
From the day you book your free site assessment to the day your granny flat is handed over, Five Star manages every step. Design, approval, construction, and handover — all under one roof, with a single point of contact throughout. Our 200+ completed Sydney builds and 4.9 Google rating reflect what that process looks like in practice.
Once your granny flat is approved and built, the next question most homeowners have is: what can I actually do with it? If you're building for investment, our granny flat investment guide covers rental returns, payback periods, and what to look for in a design that maximises yield. If you're ready to start browsing designs, our full floor plans gallery shows every option across studio, 1-bed, 2-bed, and 3-bed layouts. And for pricing context before your site assessment, see our full cost guide.
8. Frequently Asked Questions
A CDC is typically issued within 3 to 6 weeks from when a complete application is submitted to the private certifier. In some cases, particularly with straightforward standard designs on uncomplicated sites, it can come through faster. This is dramatically quicker than a DA through council, which typically takes 3 to 12 months — and sometimes longer in councils with high development application volumes.
Five Star prepares and submits the complete CDC application on your behalf. Once submitted, we liaise with the certifier directly and keep you updated on progress. You don't need to chase paperwork or manage the process yourself.
Development Applications for granny flats in NSW typically take between 3 and 12 months, depending on the council's workload, the complexity of the proposal, and whether any specialist reports or design amendments are required during assessment. Some councils in Greater Sydney are faster than others — Camden Council and Blacktown Council tend to have shorter DA processing times than councils in heritage-dense areas like Inner West or Mosman.
It's worth checking your specific council's published DA determination times on their website or via the NSW Planning Portal before committing to the DA route.
Yes — via the CDC pathway, which is assessed and approved by a private certifier rather than council. If your property meets the CDC eligibility criteria under the SEPP (Housing) 2021, you do not need to submit a Development Application to your local council at all. The private certifier's CDC is a legally recognised form of building consent.
However, you cannot build a granny flat with no approval at all. Building without any form of consent (CDC or DA) constitutes illegal development in NSW and carries significant penalties, including potential demolition orders and substantial fines. All granny flats must be properly approved before construction begins.
The minimum lot size for CDC approval under the SEPP (Housing) 2021 is 450 square metres, with a minimum street frontage of 12 metres. The granny flat itself cannot exceed 60m² of internal floor area under the CDC pathway.
If your block is smaller than 450m², CDC is not available and you would need to pursue a DA through your local council. Some councils will consider secondary dwellings on smaller lots via the DA pathway — it depends on the council's LEP and DCP provisions. A free site assessment with Five Star will confirm which pathway applies to your block.
Approval costs vary depending on the pathway and your specific site. As a general guide:
- CDC: Private certifier fees typically range from $1,500 to $3,500 for a standard granny flat, depending on the certifier and the complexity of the application
- DA: Council application fees (calculated on estimated construction cost) plus any required specialist reports can push total DA approval costs to $3,000–$10,000 or more, particularly if a heritage impact statement or other specialist reports are required
For a site-specific estimate of your approval costs, book a free site assessment. We'll give you a clear picture of the approval pathway and associated costs before any design or construction commitments are made.
