CDCs explained!! what Sydney homeowners and builders need to know
7 min read | Build Compass team | buildcompass.com.au
If you're building a new home, doing a significant renovation, or adding a granny flat in NSW, you've probably come across the term 'complying development'. For many projects, a Complying Development Certificate (CDC) is a faster and simpler alternative to a full Development Application (DA). But it comes with specific requirements that, if not met precisely, will stop your project dead.
This guide explains what a CDC is, when you can use one, and what commonly goes wrong.
What is a CDC?
A Complying Development Certificate is a combined planning and construction approval for development that complies with specific pre-determined standards set out in the State Environmental Planning Policy (Exempt and Complying Development Codes) 2008 commonly called the Codes SEPP.
Unlike a Development Application, which is assessed by your local council, a CDC can be approved by either council or a private accredited certifier. This makes it significantly faster, typically 10–20 business days compared to months for a DA. However, the trade-off is that CDCs are strictly code-based: if your project doesn't tick every box, you can't negotiate or ask for a variation. You either comply or you don't.
What types of projects can use a CDC in NSW?
The Codes SEPP sets out what types of development can be approved as complying development. The most common for residential projects include:
•New single and two-storey homes on R2 and R3 zoned land meeting the Housing Code
•Alterations and additions to existing homes (the General Housing Code)
•Secondary dwellings (granny flats) on lots over 450m² meeting the Codes
•Demolition of structures
•Swimming pools and spas on residential land
•Certain commercial and industrial development under the Commercial and Industrial Code
Critically, not all land is eligible. Heritage-listed properties, land affected by certain overlays (flooding, bushfire, acid sulfate soils), and some council areas have restrictions or exclusions that prevent complying development.
What are the key standards a CDC must comply with?
The Codes SEPP sets minimum standards across a wide range of development controls. For a new home under the Housing Code, these include:
•Lot size minimums and frontage requirements
•Floor space ratio (FSR) and site coverage limits
•Setbacks from all boundaries: front, rear and sides
•Maximum building height
•Landscaping and deep soil zone requirements
•Car parking provisions
•Privacy and overshadowing controls
•Building Code of Australia (NCC) compliance
Every one of these controls must be satisfied simultaneously. Miss one, and the CDC cannot be issued.
Why do CDC applications get rejected?
In our experience reviewing CDC documentation, the most common reasons applications are returned with requisitions or rejected include:
Setback non-compliance: The proposed building footprint infringes a boundary setback often by a matter of centimetres. This is caught at documentation review, not construction.
Inconsistent documentation: The floor plans, site plan, elevation drawings and shadow diagrams don't all tell the same story. A dimension on the floor plan doesn't match the site plan. These inconsistencies flag the application for further review.
Site eligibility issues: The land has an overlay e.g flooding, acid sulfate soils, heritage buffer zone that wasn't identified during pre-application checks. The certifier cannot approve a CDC on ineligible land regardless of how compliant the design is.
Energy compliance gaps: The BASIX certificate doesn't match the drawings. A window that appears on the plans doesn't appear in the energy model, or vice versa.
NCC non-compliance: Structural elements, fire separation, or wet area waterproofing don't meet NCC 2022 requirements. This is where a CDC review by a building consultant adds real value, catching NCC issues before lodgement saves significant time.
What is a CDC review and why does it matter?
A CDC review is an independent assessment of your documentation before you lodge with a certifier. A building consultant or certifier experienced in NSW complying development will check your drawings and supporting documents against the Codes SEPP and NCC requirements and identify any issues.
This step is optional but valuable. Certifiers charge lodgement fees and their time to review applications, if they find problems, they issue a requisition letter asking for more information, which delays your approval and can trigger additional fees. Catching issues before lodgement is almost always faster and cheaper.
How long does CDC approval take?
Under the Codes SEPP, a certifier has 10 business days to determine a CDC application once they have all required information. In practice, most straightforward applications are determined within 10–15 business days. Complex applications or those with requisitions can take longer.
Compare this to a Development Application, which goes through council and typically takes 3–6 months (sometimes longer), and the appeal of the CDC pathway is clear for eligible projects.
What happens after a CDC is approved?
Once your CDC is issued, it becomes your construction certificate and development consent in one. You can begin construction. During the build, your certifier will need to conduct mandatory inspections at critical stages (footings, frame, and final) before issuing the Occupation Certificate at the end.
Build Compass provides CDC review services for Sydney projects. We check your documentation against the Codes SEPP and NCC 2022 before lodgement to help prevent requisitions and delays. Contact us at buildcompass.com.au.
BUILD COMPASS
Build Compass provides practical building documentation, CDC reviews and client-side project management. Contact us at buildcompass.com.au or book a consultation today.
