A Complying Development Certificate (CDC) is a fast-track approval issued by a private certifier when a project meets every pre-set planning rule, and it must be determined within 20 days. A Development Application (DA) is assessed by your local council on its merits, usually takes two to three months, and allows designs a CDC cannot.
Unless your block strictly states it, you will most likely meet this decision a few weeks into your design. At first it sounds like paperwork; two acronyms, a form to fill in, something your architect will take care of. It is rather more than that. The approval pathway you take defines how far you can push your design vision, decides how long you will need to wait for approval and, on some blocks, what you are allowed to build at all.
In most cases you will not have to choose – your block and/or your design vision will decide it for you. Your architect will be there to help define which approval pathway you take.
What is a Complying Development Certificate?
A CDC is a combined planning and construction approval. It exists so that low impact developments can bypass a local council’s approval process (which can, at times, be onerous), and hence tends to be much more cost effective and quicker than a DA.
A CDC is assessed by a private certifier (rather than your local council) and is judged against a set development standard of rules which sit in the State Environmental Planning Policy (Exempt and Complying Development Codes) 2008, otherwise known as ‘the Codes SEPP’. This Code holds NSW statewide planning control, meaning they remain the same for a home in Freshwater as they do for a home in Randwick. If you hire a private certifier to issue a CDC, your local council must still be informed, although they have no say in the approval process – and neither do your neighbours.
There are strict, non-negotiable rules about the size and shape of your block, how tall you can build, and how close you can come to each boundary. Your architect will check your site against them early, because the answer to this shapes what design can be drawn.
The quantity of documentation for a CDC submission is not as onerous as what is required for most DA’s. Your private certifier will assess and approve your design if it complies with the Code. This means if just one aspect of your design does not meet the specified Code, your application will be rejected – there is no leniency or flexibility to this. For example, your site may be excluded from being able to do a CDC due to its:
- Zoning
- Slope gradient
- Proximity to environmentally sensitive areas
- Heritage status
- Development type, or
- Simple non-compliance with other elements outlined in the Code
This lack of flexibility often means you need to make compromises with your design to satisfy Code requirements, as opposed to councils granting leniency in a DA via judging a design on its merit. This may restrict the parameters through which you can achieve your design vision. If your project satisfies every one of the required Codes, a registered certifier can issue your approval without any assessment of design or local environment merit or impact.
What is a Development Application?
A DA asks your local council for permission to build a proposed design. The town planner at council subjectively assesses that design on its merits. They read your proposal against the Local Environmental Plan (LEP) and Development Control Plan (DCP) planning controls that apply to your suburb, against the matters set out in section 4.15 of the Environmental Planning and Assessment Act 1979, and against anything your neighbours may have have to say about it.
That judgement is what makes a DA slower and the more expensive option of the two pathways available for approval. It is also what makes it worth having. A planner can accept a variation when the reasoning behind it is sound, and can approve a design that steps outside a number because the result is better for it. A certifier has no such latitude, which is why most carefully designed homes on difficult Sydney blocks end up at council.
What is the Difference Between a DA and CDC in NSW?
What Rules a CDC Out?
Before you become wedded to undertaking a CDC, it’s important to understand that there are certain conditions where a CDC is not available. There is no negotiable or half-way mark. If any of the below apply to your block, your design needs to go to council via a DA.
That last row surprises people more than any other. If your architect can bring the design back inside every standard without losing design intent, then a CDC is well worth pursuing. If the only way inside the rules is to give up the thing that started your project, take the DA and the extra time. You will have your house for a great deal longer than you will have waited for it.
What Happens After You Lodge a DA?
Knowing the shape of what follows makes the wait a good deal easier to sit through. A DA moves through three stages:
- Lodgement: Council checks that everything required has been supplied, comes back for anything missing, and sends the application out to the people who need to see it – internal referrals such as heritage, trees or stormwater, and external ones such as Sydney Water or the Rural Fire Service. Where public exhibition still applies, it happens here. You are also allocated an assessment officer, who becomes your point of contact for the rest of the process.
- Assessment: Your assessment officer works through every element against the LEP and DCP planning controls for your area. Most controls carry a margin of leniency, and anything sitting outside them is assessed on its merits rather than simply refused. This flexibility is the real advantage of the DA pathway, and it is the thing a CDC cannot offer at any price
- Determination: There are three possible outcomes:
- Development Consent: Approved, either as lodged or subject to conditions. Conditions are normal and usually concern how the work is carried out. This is the ordinary outcome for a well-prepared application.
- Refusal: Declined, with the reasons set out. You can ask the council to review its decision, appeal to the Land and Environment Court, or redesign and lodge again.
- Deferred Commencement Consent: Approved in principle, but the consent does not take effect until specified matters are resolved. Not a common outcome.
Consent is not the same as permission to start. Before anything happens onsite you need a Construction Certificate, which confirms the construction detail meets the Building Code and the conditions of your consent. A CDC rolls both into the one certificate, which is one of its genuine advantages.
Pro Tip: Preparing your plans for DA lodgement is long and fiddly work, with lots of back and forward with your local council until they have all they need from both your architect and other consultants. When you are comparing design proposals, always check whether DA lodgement is included in your scope of fees. If it is not, those hours and all that follow-up lands on you.
The entire DA process takes around three months on average. Your local council should have a Service Level Agreement (SLA) noted somewhere on their website which states how long their particular planning approval process usually takes.
In general, the clearer and more detailed your initial documentation is, the faster the whole process will be. If council needs to “stop the clock” to request and await further information, or if changes need to be made to your plans, additional time will be added to the approval process. This is another reason why getting your architect to do your DA lodgement and management is the most time and cost efficient way forward.
How Long Each Pathway Takes
A CDC has to be determined within 20 days. In practice, we see it usually takes about two weeks. A DA has no such deadline, however usually runs to two or three months, depending a great deal on your council.
Source: NSW Government council league table, August 2026 snapshot, as at 8 September 2026.
These are NSW Government’s own figures, published monthly. They are gross averages and leave out the weeks a council spends waiting on missing or additional information, so it’s best to treat any one snapshot as a guide only. Because council stops the clock every time they need additional information, MILEHAM spends the time pre-lodgement ensuring every piece of information council may need or request is included in your lodgement. Every question we answer in advance is one the council cannot pause your application over later.
Council approval timelines are getting shorter, because the state is pushing them to. The NSW Government’s Statement of Expectations Order measures them against an average of 90 days, down from 105 the year before, tightening to 80 in July 2027 and 65 in July 2028.
Across a whole project, the difference between the two pathways comes to around three months. A design that suits a CDC reaches construction-ready documentation in roughly 10 to 12 months from a signed design proposal, where the same project through council runs to 13 to 15. Heritage adds about a month on top. The full stage-by-stage breakdown sits in how long does a home renovation take.
What You Give Up on a CDC
While a CDC is the quicker and more cost effective pathway. It is worth pausing a moment to appreciate what you are trading time for.
What you give up is the opportunity to maximise the design potential of your vision or site. On a DA, a planner can accept a design that sits outside planning rules, when there is a good reason behind it. A certifier assessing a CDC cannot, because the code does not allow reasons to be taken into account at all. Picture an elevated block with amazing view potential, or a block with a beautiful old tree standing in precisely the wrong place, or one where the setbacks push your living rooms away from the northern sun. On sites like these, the design that satisfies the code is very often not the best design for the site.
What is Changing in NSW
On 1 September 2026, a single statewide Community Participation Plan replaced the notification rules of more than 100 councils. Under it, a house, an addition or extension, a dual occupancy or a secondary dwelling that sits within the planning controls is no longer put on public exhibition, and the adjoining owners are no longer sent a letter of DA lodgement notification.
Exhibition has not disappeared altogether. It still applies where a design relies on a variation, where another agency such as heritage or Sydney Water has to sign off, and for larger residential buildings. Most councils also publish applications on a DA tracker as soon as they are lodged. What has gone is the letter in the letterbox.
Our own advice to involve your neighbours in your design intentions has not changed and, if anything, it matters more than it did before. Talk to your neighbours before you lodge. Not because you need their permission, but because they will be living next to your build and you will be living beside them for the next twenty years. Finding out about a two-storey addition when the scaffolding goes up is not a great way to start.
How We Approach the Decision
We can usually tell you which pathway you are on at the onsite consultation, because most of the answers above come from the block itself and the controls that attach to it. That visit is also where we can put real numbers against what each pathway means for your programme and your budget, instead of the ranges on this page.
MILEHAM holds architectural registration and a builder’s licence in the one practice, so the person weighing up the pathway is also the person who will document the approval and build from it. That matters more than it sounds. A design forced into a CDC to save three months can cost a good deal more than three months if it has to be redrawn, and a DA lodged without the reports a council was always going to ask for simply sits and waits. We put the time into a complete submission because it is the one part of the assessment period anyone on your side can actually control.
You will also have build cost estimates provided and reviewed at each stage of your design, and a fixed price building quote presented before your plans go to approval, so you will know what the design costs to build well before you have to commit to a pathway.
If you are still weighing scope rather than pathway, renovate vs knockdown rebuild is the decision that comes first, and the architecture planning process sets out where approval sits within the design programme.
DA vs CDC: Common Questions
What is the difference between a DA and a CDC in NSW?
A Complying Development Certificate is a fast-track approval issued by a registered private certifier when a project meets every pre-set planning rule in the NSW Codes SEPP. It must be determined within 20 days and combines planning and construction approval in one certificate. A Development Application is assessed by your local council on its merits against the local planning controls, usually takes around three months, and allows variations and designs a CDC cannot.
Is a CDC faster than a DA?
Yes. A CDC has a statutory determination period of 20 days. A DA has no statutory maximum and usually takes 2-3 months, though it varies a good deal between councils. Across MILEHAM’s core councils, the August 2026 figures ran from 67-98 days. Under the Statement of Expectations Order 2026, which took effect on 1 July 2026, councils are measured against an average of 90 days, tightening to 80 days from July 2027 and 65 days from July 2028. Across a whole project the difference is worth roughly three months: about 10-12 months from a signed design proposal to construction-ready documentation on a CDC, against 13-15 months on a DA.
What disqualifies a project from a CDC in NSW?
A CDC is unavailable if the property is a heritage item or draft heritage item, sits in a heritage conservation area, is rated BAL-40 or Flame Zone on bushfire prone land, is a flood control lot in a floodway or high hazard area, sits in a foreshore or mapped coastal hazard area, or is environmentally sensitive, significantly contaminated, Class 1 or 2 acid sulfate soil, or within the 25 ANEF aircraft noise contour. A CDC is also unavailable if the design exceeds any single development standard, such as height, setback or landscaped area. Failing any one of these rules a CDC out.
Can I get a CDC on a heritage property?
Generally no. A property that is a listed or draft heritage item, or that sits within a heritage conservation area, is excluded from complying development for the kind of work a renovation or rebuild involves. A narrow exception exists in conservation areas for detached outbuildings and swimming pools. Heritage projects go to council as a Development Application and typically add about a month to the programme for the heritage consultant and any referral.
Can I get a CDC on bushfire prone land?
Only below the higher bushfire attack levels. Complying development cannot be carried out on land rated BAL-40 or Flame Zone (BAL-FZ). Land at lower bushfire attack levels can proceed as a CDC, but construction must meet AS 3959 and the NSW Rural Fire Service requirements, which affects window, cladding and decking specification and therefore cost.
Which is cheaper, a DA or a CDC?
A CDC is usually cheaper on application costs, because a certifier’s fee replaces a council application fee. The larger difference is in supporting documents: a DA on a constrained site may require a statement of environmental effects, heritage impact statement, arborist report, bushfire assessment and shadow diagrams, where a CDC needs fewer. Both pathways require a BASIX certificate, a survey and engineering. Both also attract the NSW long service levy of 0.25% where the cost of work is $250,000 or more (including GST), payable before the certificate is released.
Do my neighbours get notified if I lodge a DA?
Now – not necessarily so. Since 1 September 2026, a single statewide Community Participation Plan replaced the notification rules of more than 100 NSW councils on that date, and under it a house, an extension or addition, a dual occupancy or a secondary dwelling that complies with the planning controls is not publicly exhibited and adjoining owners are not notified. Exhibition still applies where the design relies on a variation to a development standard, where another agency such as heritage or Sydney Water must sign off, and for larger residential forms, with residential flat buildings and shop top housing keeping a minimum of 14 days. Councils may still do more than the minimum, and most publish applications on an online DA tracker at lodgement.
What happens if my CDC application is refused?
A refused CDC can be redesigned to comply and lodged again, taken to council as a Development Application, or appealed to the Land and Environment Court. In practice the usual response is the first or second, because a refusal generally means a development standard was not met, and that is a design question rather than a legal one. A refused DA can be reviewed by the council under section 8.2 of the EP&A Act, or appealed to the Land and Environment Court.
Does MILEHAM manage the DA or CDC approval process?
Yes. We determine the pathway at your onsite consultation, prepare the submission and every supporting report, engage and coordinate the consultants it needs, lodge it, and respond to anything the certifier or council raises. What no architect can do is shorten the assessment itself, which belongs to your private certifier on a CDC, or to the council planner assessing your application on a DA. The part that is ours is ensuring the submission is complete so that nothing holds up council’s timeline.
Can I vary the rules slightly and still get a CDC?
Not at present. Complying development is pass or reject against every standard, with no allowance for a minor deviation from the Code. The NSW Government has proposed a complying development variations pathway that would allow a small number of minor departures, including building height to 9 metres and up to a 10% increase in gross floor area, to be determined by council within 10 days. Consultation closed on 24 June 2026 and the enabling provision, section 4.31A of the EP&A Act, has not yet commenced.
Talk to Us About Your Pathway
Which pathway suits your project comes down to your block, the controls that attach to it and what you want from the design, and none of those can truly confirmed online or over a phone call.
Start with a fifteen minute phone call, at no cost and no obligation. It is a general conversation: what you are hoping to achieve, roughly when, how we work and whether we are the right practice for your project.
If it feels like a fit, the next step is an onsite consultation. Standing on your block, with the planning controls that apply to it, is how we can tell you which pathway you are on, what it means for your programme, and provide an estimate of what the design will cost to build.
Reviewed by James Pilcher, Registered Architect (NSW ARB 10030) and Licensed Builder (NSW Licensed Contractor 272736C).
