Class 10b (NCC)
Class 10b under NCC is the building class for non-building structures: pool barriers, retaining walls, free-standing walls, masts, antennas. NCC H7 applies.
Ask Chalkline about this →Class 10b under the National Construction Code (NCC) is the building classification for non-habitable structures that are not buildings: swimming pool barriers, masts, antennas, retaining walls, free-standing walls, and similar isolated elements. Class 10b sits within NCC 2022 Volume Two Part H7 (Class 10 buildings and structures) and is distinguished from Class 10a (garages, sheds, carports, private bathhouses) and Class 10c (private bushfire shelters). Verified per NCC 2022 (2026-05-16).
Examples of Class 10b structures:
| Structure | Notes |
|---|---|
| Swimming pool barriers | Fences and walls around private swimming pools; subject to AS 1926.1 and state pool-safety laws |
| Retaining walls | Free-standing walls retaining soil; AS 4678:2002 |
| Free-standing walls | Boundary walls, garden walls, enclosure walls |
| Masts, towers, antennas | TV/radio masts, communication towers (residential scale) |
| Pergolas and shade structures (not roofed) | Where they form structures but not “buildings” |
| Chimneys (free-standing) | Garden chimneys, BBQ structures |
| Statues, monuments, planter walls | Substantial fixed structures |
| Light poles, flagpoles | Subject to height and footing engineering |
Class 10b vs Class 10a vs other classes:
| Class | Description | Examples |
|---|---|---|
| Class 1a | Single dwelling | House |
| Class 1b | Boarding house, hostel | |
| Class 2 | Multi-unit residential apartment | |
| Class 10a | Non-habitable garage/shed/carport, private bathhouse | Garage, shed, carport |
| Class 10b (this) | Non-habitable, not-a-building structure | Pool fence, retaining wall, antenna |
| Class 10c | Private bushfire shelter | (Only post-2018 regulation) |
The key distinction: Class 10a structures are buildings (with walls, roof, floor) just used for non-habitable purposes. Class 10b structures are not buildings in the usual sense; they’re isolated structural elements.
What controls apply to Class 10b under NCC:
NCC Part H7 sets the performance and DTS requirements:
| Requirement | Application |
|---|---|
| Structural adequacy | AS/NZS 1170 (wind, dead, live loads); AS 4678 for retaining walls |
| Wind loading | AS/NZS 1170.2 wind class assessment |
| Material durability | AS 5604 (timber), galvanic protection for steel, exposure category for concrete |
| Pool barrier specific | AS 1926.1 (pool barriers); state pool-safety laws (e.g. NSW Swimming Pools Act 1992) |
| Bushfire (BAL) | AS 3959 for Class 10b in BAL areas (especially pool barriers and retaining walls) |
| Heritage | Heritage controls if in HCA or Heritage item curtilage |
| Setback and easements | Council DCP overlays |
Class 10b and DA / CDC:
Class 10b structures are commonly subject to:
- Exempt development if very small and within scale limits (e.g. 1.8 m colour-bond fence, less than 1.0 m retaining wall).
- Complying Development Certificate (CDC) for some retaining walls, pool barriers, antennas under SEPP Exempt and Complying Development Codes (NSW).
- Development Application (DA) for anything outside the exempt and CDC envelopes.
Builders should check the SEPP Schedule 2 (Exempt) and Schedule 4 (Complying) NSW or the equivalent in other states for the specific Class 10b limits.
Examples of common errors:
- Treating a retaining wall over 1.0 m as exempt: above the limit, DA or CDC required.
- Pool barrier without AS 1926.1 compliance: regulator-enforceable; pool cannot be filled.
- Antenna or mast without engineering certification for wind loads: structural failure exposure.
- Class 10b confused with Class 10a: a garden chimney is Class 10b, not Class 10a; different rules apply.
- Bushfire exposure ignored: pool barrier in BAL-29+ area must use non-combustible materials per AS 3959.
Builder takeaway:
When a Class 10b structure is in the scope, identify it explicitly in the DA/CDC documentation. The NCC Part H7 requirements are distinct from H1 (Class 1) and H4 (sound insulation). Engaging a structural engineer for retaining walls over 1.0 m and antennas/masts is the standard practice; AS 4678 footing design and AS 1170 wind loading should be in the engineer’s hand.
Also known as: Class 10(b); 10b structure; non-habitable non-building structure; pool fence class (informal); retaining wall class.
Category: Compliance & NCC.
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Last updated: 2026-05-16. Verified: 2026-05-16. Quarterly review for currency.