When you plan a renovation, an extension or a new build, one of the first questions is CDC vs DA: can the project go through a CDC, or does it need a DA? Checking the zoning or ordering a Section 10.7 certificate is a good start, but on its own it rarely gives you the full picture. The answer depends on two things: what the land allows, and what you want to build. This guide explains both.
CDC vs DA in NSW: what's the difference?
A CDC is a yes-or-no test. The State Environmental Planning Policy (Exempt and Complying Development Codes) 2008, usually called the Codes SEPP, contains codes with fixed standards for lot size, height, setbacks, landscaping, privacy and more. If your land isn't excluded and your design meets every standard in the relevant code, a council or a registered certifier can issue a complying development certificate. There's no weighing up and no negotiation. Miss one standard by 100 mm and the design isn't complying development.
A DA is a merit assessment. Council weighs your proposal against its local environmental plan (LEP), its development control plan (DCP) and the likely effect on neighbours and the street, and it considers any submissions people make. It's slower and less predictable, but it can approve designs no code could, such as an addition in a heritage conservation area or a house on an awkward lot.
| CDC (complying development) | DA (development application) | |
|---|---|---|
| Who approves | Council or a registered certifier | Council, as the consent authority, in most cases |
| How it's assessed | Against the fixed standards of a state code | On merit, against the LEP, the DCP and the likely impacts |
| Neighbours | Notified before approval (14 days in the standard process) | Notified, and council considers their submissions |
| Typical time | As little as 20 days, plus 14 days' notification | Council averages of 53 to 96 days across the councils listed below |
| Before building starts | Nothing further: a CDC needs no construction certificate | A construction certificate first |
| Design flexibility | None: every standard must be met | More: the design is weighed as a whole |
What is CDC approval in NSW, and which codes apply to homes?
Several codes in the Codes SEPP matter for houses.
- Housing Code (Part 3): a new one- or two-storey house, alterations and additions to a one- or two-storey house (including an addition that makes it two storeys), and detached development such as a garage or studio.
- Housing Alterations Code (Part 4): internal alterations, and some external alterations to an existing house with no change to its footprint, floor area or height.
- Low Rise Housing Diversity Code (Part 3B): duplexes, terraces and manor houses. Our guide to building a duplex in Sydney covers it.
- Demolition Code (Part 7): knocking down a house or outbuilding.
For alterations and additions, the Housing Code is the one that counts. To use it, the lot must be:
- in zone R1, R2, R3, R4 or RU5
- at least 200 m² in area
- at least 6 m wide at the building line
- left with only one house on it when the work is finished (a lawful granny flat doesn't count against this)
- if it's a battle-axe lot, at least 12 m by 12 m, not counting an access laneway of at least 3 m
The Housing Code also rules out some work altogether: a roof terrace on the top roof, building over a registered easement, work on land identified as a landslide risk, and changes to the front of an attached house or a semi, which covers most terraces. Then the design itself has to meet every numeric standard in the code.
So a ground-floor extension at the back of a freestanding house on an ordinary suburban lot can fit the Housing Code. The same extension on a terrace in a conservation area almost never will.
What are the common reasons a CDC isn't possible?
The land is the first filter. These are the exclusions worth checking before anything else.
| Reason | What it means for you |
|---|---|
| Heritage conservation area | No Housing Code CDC, except pools, detached outbuildings and detached development other than a studio. The Housing Alterations Code still applies. |
| Heritage item on the land | No CDC on the listed part of the land |
| Lot under 200 m², or under 6 m wide | The Housing Code doesn't apply |
| Flood control lot | A CDC only on parts of the lot that council or a hydraulic engineer certifies are not floodway, flood storage, flow path or high hazard, plus extra standards |
| Bushfire: BAL-40 or flame zone | No CDC, except under the Housing Alterations Code. Lower bushfire ratings can go ahead with extra standards. |
| Aircraft noise: ANEF 25 or higher | No Housing Code CDC for a new house or additions to it. Between ANEF 20 and 25, a CDC is possible if the work is built to the aircraft noise standard. |
| Building over a registered easement | Not complying development (with a narrow exception for gutters, eaves and drainage) |
| Landslide risk identified in an LEP | Not complying development |
| Contamination or acid sulfate soils | No CDC on significantly contaminated land or Class 1 or 2 acid sulfate soils |
| Biodiversity agreements, critical habitat, environmentally sensitive land | No CDC |
| Front of a terrace or semi | Front changes need a DA |
Two of these deserve a closer look, because they rarely mean an automatic DA.
Flood-Affected Land
If your certificate says the land is subject to flood-related controls, the Housing Code can still apply. A CDC can be issued for the parts of the lot that council or a hydraulic engineer certifies are outside the floodway and other high-risk categories, with extra standards for floor levels and flood-compatible materials. The certificate tells you whether the lot is a flood control lot, and an engineer tells you what that means on the ground.
Bush Fire Prone Land
Only land rated BAL-40 or flame zone is excluded. On bush fire prone land with a lower rating, a CDC is possible with extra standards, so arrange a bushfire assessment early.
The exclusions can also apply to only part of a lot. Complying development is then allowed on the part that isn't affected, which can matter on bigger blocks.
Who approves each, and how long does it take?
A council or a registered certifier issues a CDC. The standard process allows 20 days for assessment and 14 days for neighbour notification. With a CDC, there's no separate construction certificate.
Council decides a DA. NSW Planning publishes a monthly table of how long each council takes. These were the average assessment days in September 2026:
| Council | Average assessment days |
|---|---|
| City of Sydney | 53 |
| Strathfield | 61 |
| Lane Cove | 68 |
| Bayside | 75 |
| Canada Bay | 76 |
| Canterbury-Bankstown | 77 |
| Wollongong | 88 |
| Parramatta | 94 |
| Inner West | 96 |
The NSW Government has set councils a target average that drops each year, to 65 days from July 2028. The figures change every month, so check the current table for your council. After a DA is approved, you need a construction certificate from council or a registered certifier before any work starts.
What do a CDC and a DA cost?
Approval fees are a small part of the total, but they're the part people ask about first.
- DA fees are set by the state on a sliding scale tied to the estimated cost of the work. For a $400,000 renovation, the maximum base fee works out at about $1,960. If your DA has to be notified to neighbours or exhibited, there's a further fee of up to about $1,530. Council's own fee schedule has the exact figures.
- The construction certificate after a DA is a separate fee, quoted by council or the certifier.
- A CDC is quoted by the certifier for your job.
- Both pathways need the same groundwork: a survey, design and documentation, engineering, a BASIX certificate if the work is valued at $50,000 or more, and any reports the land calls for. See what an architect costs in NSW and our fees page for the design side.
Our view: the approval fee is rarely what should decide between a CDC and a DA. Time, risk and what the house actually needs matter more.
Can you start with a CDC and switch to a DA?
Yes. You can lodge a DA instead. Sydney homeowners have reported starting down the CDC route, then finding one standard they couldn't meet, such as a side wall a little too close to the boundary. What you lose is the time and the design work spent fitting the code.
That's why the order matters. Check the land first. Then test the design against the code's standards while it's still a sketch, before anyone produces a full set of drawings. If the house you need only fits a CDC after major compromises, a DA is usually the better choice, even though it takes longer.
Where should you start?
Our free workbook, CDC or DA: where do you start?, is a self-guided check for single dwellings in NSW. You sit down with your own property documents and work through four gates: the land, the title, what runs under the ground, and what you want to build. By the end you have a preliminary read on whether your property leans towards a CDC, needs more investigation, or is better suited to a DA.
It's built for two kinds of people. If you already own the property, use it to understand what your place can and can't do before you commit to a design. If you're about to buy, use it before you sign. It gives you a first answer and shows you where the real questions sit, so you know what to ask a certifier or an architect.
We're also building the CDC Checker, an online tool that's coming soon. You upload your council's Section 10.7 certificate and it tells you whether a CDC looks available, whether the project needs a DA, or whether something needs a closer look first.
CDC Checker · coming soon
Could your project qualify for CDC instead of a DA?
Choose your project type, enter your property address and upload your Section 10.7 Planning Certificate. Our online CDC Checker reviews your property's planning information to help identify whether:
- CDC may be available for your proposed project.
- A DA may be required instead.
- Further investigation is needed due to constraints such as heritage, flooding, bushfire, etc.
Get a clearer understanding of your potential approval pathway before committing to detailed design.
- Renovate inside
- Extend my home
- Knock down and rebuild
- Build a duplex
- Build a granny flat
Preliminary NSW residential planning assessment. Not a CDC approval or substitute for professional advice. 1 free check per new user.
What this means for you
- Order a Section 10.7 planning certificate for the property. Our guide to reading a Section 10.7 certificate explains each part.
- Read the complying development section first. If the Housing Code says "No", the reason given tells you why.
- Check your lot against the Housing Code: zone, at least 200 m², at least 6 m wide at the building line.
- Look at your title for registered easements, and at any flood, bushfire or aircraft noise notes.
- Decide what the design must do. Front changes on a terrace, an addition in a conservation area or a design that needs flexibility all point to a DA.
- If you're in a heritage conservation area, read our guide to renovating in an Inner West heritage conservation area.
If you'd rather hand it over, we manage DA and CDC approvals from design through to a decision. Our feasibility study answers the CDC or DA question for your site in writing, before you pay for a full design.
Questions people ask
What is CDC approval in NSW?
A complying development certificate (CDC) is a fast-track approval for straightforward work that meets every standard in a state code, mainly the Codes SEPP. Council or a registered certifier issues it, usually much faster than a DA, and you don't need a separate construction certificate. If the land is excluded, for example by a heritage conservation area or a high bushfire rating, or the design misses a single standard, a CDC isn't possible and the project needs a DA.
Is a CDC always faster than a DA?
Usually, but not always. The standard CDC process allows 20 days for assessment and 14 days for neighbour notification, while council DA averages ranged from 53 to 96 days across the councils listed above in September 2026. A CDC can still stall when documents are missing or the design needs reworking to meet a standard, and weeks spent redesigning to force a CDC can cancel out the saving.
Can neighbours object to a CDC?
Neighbours are notified before a CDC is issued, but a CDC isn't a merit assessment. If the land qualifies and the design meets every standard in the code, the certifier assesses it against those standards only. A DA is different: council must consider the submissions it receives, which is why neighbour concerns can lead to changes in a DA.
Can alterations and additions go through a CDC?
Many can. The Housing Code covers alterations and additions to a one- or two-storey house, including a first-floor addition, on a residential lot of at least 200 m² and 6 m wide, as long as the land isn't excluded and the design meets every standard. Internal work and some ground-floor changes can use the Housing Alterations Code, which also applies in heritage conservation areas. Changes to the front of a terrace or semi need a DA.
Do I need a construction certificate with a CDC?
No. You don't need a construction certificate if you have a CDC. With a DA, you need a construction certificate from council or a registered certifier before any work starts. In both cases you must appoint a principal certifier before building begins.
Sources
- Complying development, NSW Planning
- State Environmental Planning Policy (Exempt and Complying Development Codes) 2008, NSW Legislation
- Approvals: building or renovating a home, NSW Government
- Council league table, NSW Planning
- Statement of Expectations Order, NSW Planning
- Environmental Planning and Assessment Regulation 2021, Schedule 4 (fees), NSW Legislation
- BASIX: alterations and additions, NSW Planning Portal
- Development application (DA) process, Inner West Council
