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Planning a dual occupancy development? What to consider from a certification perspective.
Key considerations to keep your dual occupancy project compliant, efficient, and on track from planning through to approval.
28 Apr 2025
Mandatory Inspections
From start to finish, every project requires key inspections to make sure it’s built right. Book yours by 3pm, and we'll be there the next day.
Mandatory inspections, sorted.
Mandatory inspections are a legal requirement for all building works in NSW. They happen at key stages of construction to confirm your project is progressing as it should, in line with your approval conditions.
At Buildcert, we take the guesswork out of the process. Our certifiers work with you from the start to confirm which inspections are required, when they need to happen, and what documentation will be checked. The result? No confusion, no delays, just peace of mind knowing your project is on the right path.
If you are in our service area and book by 3pm, we can even be on site the next day*.
*working days only
[ Inspection stages ]
What inspections are required for my project?
The mandatory inspections you’ll need depend on your project’s building classification. As part of our role as Principal Certifier, we’ll nominate the inspections specific to your approval so you know exactly what to expect.
Here’s the minimum required by law:
Class 1 & 10 buildings
Includes dwellings, secondary dwellings, dual occupancies (side by side), multi-residential terraces, sheds, pools, retaining walls, carports, and other ancillary residential development.
- Piers/Footings – after excavation, before concrete is poured
- Slabs or reinforced concrete – before concrete is poured
- Framing – before covering or insulation of floor, wall or roof framing
- Waterproofing – before the membrane is covered
- Stormwater – before drainage connections are covered
- Completion – once all works are finished
Note: For swimming pools, a barrier inspection must be booked as soon as practical after the barrier is installed.
Class 2, 3 & 4 Buildings
Includes apartment buildings, group homes, boarding houses, and buildings for children, the elderly and people with a disability.
- Piers/Footings – after excavation, before concrete is poured
- Fire service penetrations – at least one of each type of protection method on each storey
- Fire-resisting junctions – before covering internal fire-resisting construction bounding a sole occupancy unit (SOU). At least 30% of SOUs must be inspected on each storey
- Waterproofing – before the membrane is covered
- Stormwater – before drainage connections are covered
- Completion – once all works are finished
Class 5, 6, 7, 8 & 9 Buildings
Includes office buildings, retail shops, restaurants, cafés, hairdressers, warehouses, carparks, factories, hospitals, schools, childcare centres and other public buildings.
- Piers/Footings – after excavation, before concrete is poured
- Fire service penetrations (Class 9a or 9c only) – at least one of each type of protection method on each storey
- Stormwater – before drainage connections are covered
- Completion – once all works are finished
Get your inspections sorted.
[ Missed inspections ]
What happens if a mandatory inspection is missed?
Missing an inspection isn’t something that can be brushed off. By law, an Occupation Certificate can’t be issued if a mandatory inspection hasn’t taken place, unless it’s deemed “unavoidable” and backed by solid evidence. Simply forgetting or miscommunication isn’t considered enough.
If an inspection is missed, the owner must be formally notified, and extra steps are required. This may include a statutory declaration explaining the circumstances, and supporting documents such as engineering certifications, first and/or third party certification and photos to prove compliance. Even then, approval is not guaranteed, which is why booking inspections on time is critical.
