What’s a Building Certifier, and Why Do You Need One?
In NSW, if you're going down the CDC (Complying Development Certificate) path, a Building Certifier plays a vital role.
A Building Certifier (also called a Principal Certifying Authority or PCA) is an independent professional who checks that your home is designed and built safely, legally, and to code.
A Building Certifier will do an assessment for your CDC and then they will join you throughout your entire construction journey, performing scheduled inspections throughout.
What does a Building Certifier do?
Your Building Certifier will complete works according your agreed scope of works.
Typically, a Building Certifier will:
- Review all project documentation, including:
- Your architectural and engineering plans
- Your approved BASIX Certificate
- Specifications and design documents
- Confirm that your proposal complies with the State Environmental Planning Policy (SEPP) – Complying Development Codes 2008, as well as SEPP Housing 2021 (for secondary dwellings, if applicable) .
- Identify any areas of non-compliance and recommend necessary modifications to secure CDC approval.
- Issue the Complying Development Certificate, allowing you to commence construction without a full Development Application (DA).
- Undertake mandatory inspections at key construction stages such as slab, framing, waterproofing, and final fit-out.
- Provide all interim compliance certificates and issue the Final Occupation Certificate once construction is complete and compliant.
Unlike going through council (DA route), CDC is a
faster, simpler path — but it still requires expert oversight. That’s where your Building Certifier comes in.
Barry's Toolbox
Don’t rush this one — your certifier is like a second set of eyes on your build!
Ask if they can handle both
CDC approval and
your construction inspections — many certifiers offer it as a package, and it keeps things simpler for you.
What to Look for in a Building Certifier
Choose someone who:
- Is accredited and experienced with CDC approvals for new homes or granny flats
- Is responsive and clear in communication
- Provides a transparent quote that lists all potential fees
- Has availability in line with your build timeline
Before You Begin: What You’ll Need Ready
To get accurate quotes from Building Certifiers, you'll need:
- A copy of your building plans (site plan, floor plan, elevations)
- A copy of your BASIX Certificate
- Details about your site (lot number, address, any known constraints)
This is a key decision — your Certifier will stay involved throughout construction, conducting inspections and helping issue your Occupation Certificate at the end.
Average Timeframe
For this task, Pros typically provide quotes within
3–5 business days.
When Can I Expect Quotes?
Timeframes often vary based on demand and the type of Pro you're engaging (e.g. a plumber). If additional communication or clarification is needed is needed, the quoting process may take longer.
Don't be alarmed if you don't receive quotes or communication from any Build Buddy Pros straight away. Some work is more complex and the Pro may need time to comprehend your documents or scope of work. Depending on the job, there may even be some work required by the Pro before they are able to quote (e.g. a site visit might be required).
If the average timeframe indicated here has passed, and you have not received any messages or quotes, please feel free to contact the Build Buddy Expert Guidance and Support team for an update on quoting for this task.
Frequently Asked Questions
Do I legally need a building certifier to build?
Yes — it’s a legal requirement in NSW to have a registered Building Certifier involved before and during construction. Without them:
- You can’t get a CDC or Occupation Certificate
- Your build is considered unauthorised, even if it’s on your own land
- You may face fines, delays, or be unable to sell or insure the property
Glossary
Below is a breakdown of each inspection your Building Certifier may carry out during construction. These checks ensure your project complies with all relevant building codes and regulations at critical stages.
| Term | Definition |
|---|---|
| Footing Inspection | This inspection checks the trench or footing before concrete is poured for your retaining walls. The certifier confirms correct depth, reinforcement, and placement according to the approved engineering plans. |
| Core Filling Inspection | Once your retaining wall blocks are laid, they need to be core filled (filled with concrete for strength). This inspection confirms the correct reinforcement and ensures the wall is structurally sound before the fill is poured. |
| Pier/Pad Inspection | This is carried out before pouring concrete piers or pad footings. The certifier checks the location, depth, steel reinforcement, and stability of piers or pads that will support parts of the building — like posts, columns, or verandahs. |
| Slab on Ground (Steel) Inspection | Just before your main slab is poured, the certifier checks the steel reinforcement and formwork. This inspection ensures that your slab is built to engineering specs and ready for concrete. |
| Blockwork Core Filling Inspection | Similar to retaining walls, if your basement walls are made from concrete blocks, they must be core filled for strength. This inspection checks reinforcement and wall integrity before core fill goes in. |
| External Waterproofing Inspection | Before your basement walls are backfilled (i.e. soil placed around them), this inspection ensures waterproofing membranes have been properly applied. This protects the basement from future leaks or moisture damage. |
| Suspended Slab (Steel) Inspection | If your build includes a suspended concrete slab (a slab that’s not on the ground), the certifier checks steel reinforcement and structural formwork before the concrete is poured. This is critical in basement construction or multi-level builds. |
| Stormwater Drainage Connection Inspection | This inspection checks the underground stormwater system on your property — including pits, pipes, and connections. The certifier ensures that runoff will be directed correctly and won’t cause flooding or drainage issues. |
| Frame Inspection | After framing is complete (before walls and roof cladding go on), the certifier inspects the wall studs, floor joists, lintels, and roof structure. They’re checking that it matches plans and is safely tied down to withstand wind loads and movement. |
| Wet Area Flashing Inspection | This is done before tiling or cladding goes up in wet areas (like bathrooms, laundries, and kitchens). The certifier checks waterproofing membranes and flashing to prevent future water leaks or structural damage. |
| Completion Inspection | This final inspection is carried out when all work is complete. The certifier confirms that everything meets the Building Code of Australia, all mandatory inspections have passed, and the home is safe to occupy. Once approved, they’ll issue your Occupation Certificate, which is required to legally move in. |
How to Complete this Task?
STEP 1
Review and Adjust the Scope of Works
Timeframes may vary based on demand and the type of Pro you're engaging (e.g., a plumber). If additional communication or clarification is needed, the quoting process may take longer.
STEP 2
Confirm Required Documents Are Uploaded
Check that the following required document(s) are uploaded for this task. These are essential to proceed:
STEP 3
Update the Quality Assurance Checklist
Go to the
Quality Assurance tab in this task and review the checklist. Edit any details to suit your project requirements. Being clear and upfront helps set expectations with the Pro. Updating the checklist before requesting quotes ensures everyone is aligned.
STEP 4
Request Quotes
Click the
orange ‘Request Quotes’ button to start the quoting process.
STEP 5
Review the Quotes
Once you receive quotes:
- Review each one carefully, including the payment schedule and any special terms
- Download attached quote documents for detailed review
- Check each Pro’s profile and read past client reviews
STEP 6
Communicate with the Pro
If needed, message or call the Pro to clarify details or negotiate terms.
STEP 7
Accept a Quote
Choose the quote that best suits your needs. Once you accept a quote, any other pending quotes will be automatically declined. An agreement will automatically be generated.
STEP 8
Complete the Tasks In Your App
New tasks will appear to guide you through this job — follow each step carefully. Make sure to use the
Quality Assurance Checklist, and refer to your
contract and
final Scope of Works whenever needed.
NEED HELP?
Reach Out to Your Build Buddy Pro
If you have any questions or need a hand, your Build Buddy Pro is your best first contact. They’re a licensed expert in their field and can understand the ins and outs of your project. You can message them via the platform, or you can call them directly.
If you have already contacted your Build Buddy Pro and still need further assistance, the Build Buddy Expert Guidance and Support team are here to help. They will be able to guide you on your next steps or help you find answers to any questions you may have.
