What is a CDC (Certificate of Design Compliance) and when is it required?
- Jun 9, 2025
- 2 min read
Updated: Jul 24, 2025
A Certificate of Design Compliance (otherwise known as a CDC) is the formal certification from a registered building surveyor declaring all drawings, specifications and technical documents for the proposed building or structure satisfy the National Construction Code (NCC) and applicable Australian Standards. It serves as evidence that the proposed design is compliant, allowing the building permit application to be processed.
The CDC is issued prior to submission of a BA1 – Application for Building Permit (certified) for both residential and commercial buildings.
A CDC allows a building surveyor to assess the proposed scope at the design stage of the building process and expedites the submission through council, saving time and money for the builder or client.
Bushfire Considerations
For certain building classes (1, 2, 3, 9), the building surveyor must also provide specific statements and information related to bushfire protection, as outlined in the updated building regulations.
Is a CDC required for commercial buildings? Yes. A certified building application is to be submitted to the local government for all commercial Class 2 – 9 buildings.
What buildings do you certify? We provide building certification services for both residential and commercial buildings.
CDC's for residential buildings (class 1 & 10 buildings):
New single and multi-storey dwellings and ancillary dwellings (class 1A and 1B)
Garages, carports, pergolas and sheds (class 10A)
Swimming pools, screen walls, fencing and retaining walls (class 10B)
Multi Grouped dwellings and dual occupancies
Prefab and modular housing
CDC's for commercial buildings (class 2-9 buildings):
All commercial buildings
Mining and civil works
Agriculture and marine
For further information on when a Building Permit and CDC is required check out our website for residential building certification and commercial building certification.
For further reading check out the following links:
Great blog post on Certificates of Design Compliance (CDC)! As someone navigating building projects in Perth, I found your breakdown super helpful—explaining how a CDC from a registered surveyor certifies that designs meet the National Construction Code and Australian Standards before the BA1 permit submission is a game-changer for saving time and costs on residential or commercial builds. It's especially relevant when tackling complex designs, much like selecting focused Science Research Topics in fields such as CRISPR gene therapy or sustainable computing, where early compliance checks prevent costly revisions down the line. Love the tips on bushfire statements for Classes 1, 2, 3, and 9—definitely bookmarking this for my next project to streamline council approvals without the headaches! Keep sharing…
Explaining what a CDC (Complying Development Certificate) is and when it’s required in a clear, straightforward way makes a planning and building topic a lot easier to follow, especially for people who aren’t familiar with development rules. Laying out what CDCs cover, how they differ from other approvals, and the situations where you actually need one gives readers a practical sense of how the process works without making it feel too technical. That kind of simple breakdown helps anyone dealing with construction or property issues understand the basics and what steps they might need to take. For students working on related assignments or reports, Assignment Help UK can help them organise their ideas, understand what’s required, and structure their work so…