The 11 Fire Safety Defects NSW Keeps Finding in New Apartments (NCC 2022 and 2025)
Building Commission NSW lists eleven fire safety defects its auditors keep finding on apartment sites, from fire-rated walls and penetrations to fire doors, stairs and hydrants. Here is each one with its NCC 2025 and NCC 2022 clause and when to catch it, plus a fire door gap calculator.
Building Commission NSW audits apartment buildings while they are going up, and publishes the defects its auditors find often as the Building Defects Library: 40 of them in Class 2, 3 and 9c buildings, across waterproofing, fire safety, structure, building enclosure and services, each with the clauses it breaches.
This series rewrites the Library one building element at a time and adds what it leaves out: the NCC 2025 clause beside the NCC 2022 one it was written against, the stage of construction where each defect is cheapest to catch, and what to keep as evidence. This is part 2 of five: fire safety, the second most commonly reported serious defect in the 2025 strata survey of NSW Class 2 buildings of four or more storeys.
In one minute
Fire safety defects were reported in 28% of the 520 buildings in the 2025 strata survey, second only to waterproofing, and in 37% of the buildings registered in 2018.
The Library lists eleven: two in fire-rated walls and penetrations, three in fire doors, four in the exits and the stair, and two at the hydrants.
NCC 2025 changed three of the clauses behind them: D3D16 (thresholds), C4D10 (services in the stair) and E1D2 (hydrant systems). Every clause kept its number, and the rest are unchanged for these defects.
Fire doors follow AS 1905.1:2015 in both editions. Their gaps change when the floor finish goes down, so measure after it.
Which edition applies depends on your state and a date. NSW, Queensland, South Australia and Tasmania are on NCC 2022 until 1 May 2027, and the Northern Territory has not adopted NCC 2025.
How common are fire safety defects in new apartments?
The 2025 strata survey, run by Building Commission NSW with Strata Community Association NSW, covered 520 Class 2 buildings of four or more storeys registered from July 2018 to June 2024. Fire safety systems, passive and active, were the second most reported serious defect after waterproofing, in 28% of buildings; the 2023 survey found 24%, and the report calls the two results similar (page 12).
The report notes that defects come to light as buildings age: among buildings registered in 2018, 30% had a fire safety defect at the 2023 survey and 37% at the 2025 survey (page 13). Strata managers reported, anecdotally, that some were found at the first annual fire safety inspection, and others when owners commissioned a report before the two-year warranty for minor defects ran out (page 10). For 8% of buildings with a fire safety defect, the council had issued a fire safety order (page 36).
The survey counts active systems too, such as the missing smoke detectors and misaligned sprinkler heads in one case study (page 44). The Library's eleven are mostly the passive side that a site inspection can see.
Which NCC edition applies to my project?
The Library is written against NCC 2022. NCC 2025 is published nationally but called up by each state on its own date, and the date that decides is usually when the approval is applied for or issued, not when work starts. Your certifier or building surveyor confirms the edition for a project.
| State | In force on 7 November 2026 | NCC 2025 from | The date that decides |
|---|---|---|---|
| NSW | NCC 2022 | 1 May 2027 | Construction certificate application made |
| VIC | NCC 2025 | 1 May 2026 | Building permit issued |
| QLD | NCC 2022 | 1 May 2027 | Building development application approved |
| SA | NCC 2022 | 1 May 2027 | Building consent application made |
| WA | NCC 2025 (NCC 2022 may still be used for permit applications made by 30 April 2027) | 1 May 2026 | Permit application made |
| TAS | NCC 2022 (NCC 2025 applied from 1 May to 4 June 2026) | 1 May 2027 | Certificate of likely compliance issued |
| ACT | Either, chosen per project | Required for approvals from 1 May 2027, unless a DA or works approval was lodged before 1 November 2026 | Building approval determined |
| NT | NCC 2022 | Not adopted | Building permit granted |
The clauses below are national. NSW has its own D3D14(1) and D3D16 in both editions, and South Australia its own D3D16 and extra E1D2 clauses in NCC 2022, but they add rules for entertainment venues, farm buildings and grain stores, not apartments. NSW also rewords C4D12(4) in both editions, but requires the same doors. No state varies the fire wall, penetration, stair services or headroom clauses here.
What changed for fire safety in NCC 2025?
Less than for waterproofing. Every clause behind these defects kept its number, and only three of the rules that matter here changed:
| Requirement | NCC 2022 | NCC 2025 |
|---|---|---|
| Fire-rated walls up to the floor or roof above | C1P2, C3D8(3), Specification 5 | The same |
| Service penetrations, to AS 4072.1:2005 and AS 1530.4:2014 | C1P8, C4D13, C4D15 | The same, with the ventilation route, C4D15(2)(b), reworded |
| Fire doors, to AS 1905.1:2015 | C4D9, C4D12, C4D5, S12C2 | The same |
| Services in a fire-isolated exit | C4D10, D3D8 | C4D10 adds wiring, sensors and the like for the exit's pressurisation system; D3D8 the same |
| Thresholds | D3D16: exceptions listed by building type and by where the doorway opens | D3D16 rewritten: a step or ramp only where the doorway opens to an external space |
| Headroom, risers and goings | D2D7, D3D14 | The same |
| Fire hydrants | E1D2, to AS 2419.1:2021 | E1D2, to AS 2419.1:2021, or AS 2118.6 or FPAA101H where applicable |
The two wall and penetration defects
Both keep fire on one side of a fire-rated wall or floor. Our FRL guide explains how the required level is set.
1. The fire-rated wall stops at the ceiling
A fire-rated wall stops at an ordinary suspended ceiling instead of running up through the ceiling space to the slab or roof above, so fire and smoke travel over the top.
| Both editions | C1P2(1); C3D8(3): a fire wall between fire compartments goes up to the underside of a floor with the fire wall's FRL, or to the underside of the roof covering; S5C11(1)(b) (Type A), S5C21(1)(c) (Type B) and S5C24(1)(d) (Type C) take other rated internal walls to the underside of the floor or roof above, or to a ceiling with at least 60 minutes' resistance to the incipient spread of fire (in Type A, only a ceiling directly below the roof). A wall that stops at such a ceiling is not this defect. |
| Standard | None sets the height; build the wall and its head joint as its tested or assessed system shows |
| Catch it | Before the ceiling is lined. Walk the ceiling space above every rated wall and photograph each one where it meets the slab, with its head joint sealed. |
2. Services pass through without tested protection
Pipes, cables and ducts pass through a fire-rated wall or floor with no collar, wrap, damper or sealant, or with a product used outside its tested system.
| Both editions | C1P8(1)(b); C4D13: a service through a rated floor is protected by a shaft or under C4D15; C4D15(2)(a): the service, the element and the protection match a prototype tested to AS 4072.1 and AS 1530.4, or differ only as Section 4 of AS 4072.1 allows |
| Standard | AS 4072.1:2005 and AS 1530.4:2014, in both editions |
| Catch it | Before ceilings and riser walls close. Check each penetration against its test or assessment report (service, size, wall or floor, product), and photograph and number every one. |
The three fire door defects
Both editions send every required fire door to AS 1905.1:2015 through S12C2(1)(a). The Standard covers the whole doorset: leaf, frame, hardware and installation.
3. The fire door does not close and latch by itself
Let go of the door and it stays open or stops short: the closer is missing or badly set, the latch does not engage, or a wedge or hand-set bolt defeats it.
| Both editions | C4D9(1): a self-closing or automatic-closing –/60/30 fire door at each doorway into a fire-isolated stair, unless it opens to a road or open space; C4D12(4)(a): a self-closing –/60/30 fire door at each of the doorways from a sole-occupancy unit listed in C4D12(1), in Type A construction (NSW rewords C4D12(4), with the same door); C4D5(2) and S12C2(1)(a): to AS 1905.1 |
| Standard | AS 1905.1 cl 2.1.3: the door must shut on its own and, unless it slides, latch on its own too; cl 2.1.4.2: no deadbolt, frame latch, swing bar or other hand-worked device that could stop it latching by itself |
| Catch it | At hardware fit-off, and again after floor finishes. Open each fire door fully and let it go: it must close and latch unaided. |
4. The gaps around the fire door are too big
The gap between the leaf and the frame, the doorstop or the floor is wider than the Standard allows, so smoke and flame can get through. A new floor finish changes the floor gap.
| Both editions | C1P8(1)(a); C4D5(2); S12C2(1)(a): to AS 1905.1 |
| Standard | AS 1905.1 cl 5.5.1: 3 to 10 mm between the leaf and the floor covering, and no more than 25 mm to a non-combustible threshold; cl 5.5.2: a mean of no more than 3 mm along the head and along each stile of a rebated frame; cl 5.5.3: a mean of no more than 3 mm to the doorstop, and no more than 5 mm at any point |
| Catch it | After floor finishes, before the door is certified. Measure at several points, record the readings on the door schedule, and check them in the calculator below. |
5. The fire door frame is hollow
A steel fire door frame in a masonry wall is fixed but left hollow, so the doorset no longer matches the one that was tested.
| Both editions | S12C2(1)(a): to AS 1905.1 |
| Standard | AS 1905.1 cl 5.3.2: in masonry, the head and jamb cavities of a metal frame are filled progressively with cement mortar, concrete, non-shrink grout or another material that will not fuse below 1000 °C, unless a full-scale fire test showed another fixing works |
| Catch it | As the masonry goes up around the frame. Photograph the grouting; later, a hollow frame sounds hollow when tapped. |
The four exit and stair defects
A fire-isolated stair is a way out that must stay clear of fire and smoke. These four cover what goes into the exits and how safely people move through them.
6. Services run through the fire-isolated stair
Pipes, ducts or cables that do not serve the stair pass through it, or a service riser opens into it.
| NCC 2025 | C4D10(1): only the wiring D3D8(6) allows (for the stair's lighting, detection or pressurisation, its security, surveillance or management system, an intercom or alarm to D3D27, and hydrant or sprinkler valve monitoring), pressurisation ducting with an FRL of at least –/120/60 where it passes through the rest of the building and no opening into it, water supply and test drain pipes for fire services, and (new) wiring and sensors for the stair's pressurisation; D3D8(1): no access from the stair to service shafts or services, other than fire-fighting or detection equipment; D3D8(3): no gas in any required exit |
| NCC 2022 | C4D10(1): the same list without the pressurisation wiring and sensors; D3D8 the same |
| Standard | None: the lists are in the NCC |
| Catch it | On the coordinated services drawings before rough-in, and again before the stair is lined. Anything in the stair the lists do not name is a defect. |
7. There is a step at the stair door
The floor steps up or down at the door into the stair, where the landing and the corridor finish at different levels. People leaving in a hurry trip on it.
| NCC 2025 | D3D16(1): no step or ramp closer to the doorway than the width of the door leaf, unless the doorway opens to an external space; a stair door off a corridor does not |
| NCC 2022 | D3D16(1): the same rule, with exceptions for Class 9a and 9c care areas, accessible doorways, and doorways to a road, open space, external stair landing or external balcony; none covers a stair door off a corridor |
| Standard | None |
| Catch it | When slab and landing levels are set, before the pour; then check the finished floors either side of each stair door. |
8. There is not enough headroom in the exit
A bulkhead, beam, duct or sprinkler pipe hangs below 2 m in a corridor or stair that is a required exit or the way to one.
| Both editions | D1P4; D2D7(1): an unobstructed height of at least 2 m throughout a required exit or path of travel to an exit, reduced to no less than 1980 mm at a doorway |
| Standard | None |
| Catch it | On the reflected ceiling and services drawings; then, before the ceilings close, measure under everything that hangs below them. |
9. Risers and goings are not constant
Steps in one flight differ in height or depth, for example the first or last riser where the landing finish differs from the treads.
| Both editions | D3D14(1)(c): constant through each flight, which means adjacent risers, or adjacent goings, within 5 mm and the largest and smallest in a flight within 10 mm; each also inside Table D3D14 (D3D14(1)(b)) |
| Standard | None |
| Catch it | When the flight is formed or arrives, and again after finishes: measure every riser and going, finished surface to finished surface. The free stair calculator checks them against Table D3D14; our D3D14 guide explains the clause. |
The two hydrant defects
Both editions send the hydrant system to AS 2419.1:2021 through E1D2(2); NCC 2025 also allows AS 2118.6 or FPAA101H where they apply.
10. The hydrant outlet points down too steeply
A fire hydrant valve is installed with its outlet angled further below horizontal than the Standard allows.
| NCC 2025 | E1P3; E1D2(2): to AS 2419.1, or AS 2118.6 or FPAA101H where applicable |
| NCC 2022 | E1P3; E1D2(2): to AS 2419.1 |
| Standard | AS 2419.1:2021 cl 3.2.2.1(c): the outlet angled no more than 35° below level; cl 3.2.2.1(b) also sets the valve's centre line between 750 and 1200 mm above the floor or platform |
| Catch it | At installation, before commissioning: check the outlet angle with a digital level, and its height. |
11. Nothing is kept clear in front of the hydrant
A wall, door swing, cupboard or storage cage sits in front of the hydrant, leaving the fire brigade no room to connect and lay out hose.
| NCC 2025 | E1P3; E1D2(2), as for defect 10 |
| NCC 2022 | E1P3; E1D2(2): to AS 2419.1 |
| Standard | AS 2419.1 cl 3.2.2.2: at least 1 m clear directly in front of the outlet (except where cl 7.3.3 applies), and in a fire-isolated stair at least 500 mm from any point of a door swing |
| Catch it | Overlay the hydraulic layout on the architectural plans, and check again after doors and joinery are fitted. |
Is that fire door gap within the limit?
Pick the gap you measured and enter it. The calculator checks it against AS 1905.1, which both editions call up for every required fire door.
When should each defect be caught?
Each defect has a moment when it is still in view and cheap to fix:
| Stage | Check | Defects |
|---|---|---|
| Design and coordination | Services out of the stair, hydrant clear space, heights under bulkheads, floor levels at stair doors | 6, 7, 8, 11 |
| Before the pour, or when the stair goes in | Levels at each stair door, risers and goings | 7, 9 |
| As masonry goes up around door frames | Frames grouted | 5 |
| Before ceilings close | Rated walls to the slab, penetrations against their tested systems | 1, 2 |
| Services fit-off | Hydrant angle and clearances, nothing in the stair that C4D10 does not list | 6, 10, 11 |
| After floor finishes | Fire doors close, latch and have their gaps measured; headroom and risers rechecked | 3, 4, 8, 9 |
How can AEC Assistant help?
AEC Assistant works from the edition and state of your project, and cites the clauses it relies on.
Before construction: upload the drawings to a project and ask it to review the fire separation, door, stair and hydrant details. It marks each issue it finds on the sheet, with the clause.
For the site: it builds an inspection and test plan from your specification, with hold points like the ones above.
When a defect is found: it turns site photos and notes into a defect register and drafts the direction notice or defect letter, citing the clause for your edition.
Where to read the source
Building Defects Library, Building Commission NSW, v1.1, June 2025 (written against NCC 2022)
2025 Strata Defects Report, Building Commission NSW with Strata Community Association NSW, November 2025
NCC 2025 Volume One, Sections C, D and E and Specifications 5 and 12, and NCC 2022 Volume One with Amendment 2, from the ABCB
AS 1905.1:2015, AS 4072.1:2005, AS 1530.4:2014 and AS 2419.1:2021, from Standards Australia
This is part 2 of five in our rewrite of the Building Defects Library. The others cover waterproofing, structure, building enclosure and services, and the series index lists all 40 defects.
Questions this guide answers
Which fire safety defects does the NSW regulator keep finding?
Building Commission NSW's Building Defects Library lists eleven that its auditors find often on apartment sites: a fire-rated wall that stops at the ceiling; service penetrations without tested protection; fire doors that do not close and latch, have gaps that are too big or have hollow frames; services in a fire-isolated stair, a step at the stair door, too little headroom in an exit and uneven risers and goings; and hydrants with outlets angled too steeply or no clear space in front. Fire safety defects were reported in 28% of the 520 buildings in the 2025 strata survey.
What gaps are allowed around a fire door?
AS 1905.1:2015, which NCC 2022 and NCC 2025 both call up for every required fire door through S12C2, allows 3 to 10 mm between the bottom of the leaf and the floor covering, and no more than 25 mm to a non-combustible threshold (cl 5.5.1). For a side-hung door in a rebated frame, the gap is a mean of no more than 3 mm along the head and along each stile (cl 5.5.2), and to the doorstop a mean of no more than 3 mm with no point over 5 mm (cl 5.5.3).
Can there be a step at the door into a fire-isolated stair?
No, in either edition. D3D16 bars a step or ramp closer to a doorway than the width of the door leaf. NCC 2025 allows one only where the doorway opens to an external space. NCC 2022's exceptions cover Class 9a and 9c care areas, accessible doorways, and doorways that open to a road, open space, external stair landing or external balcony. A stair door off a corridor is none of these.
What services can run through a fire-isolated stair?
Only those C4D10 lists: wiring that D3D8(6) allows (for the stair's lighting, detection or pressurisation, its security, surveillance or management system, an intercom or alarm to D3D27, and monitoring hydrant or sprinkler valves), pressurisation ducting with an FRL of at least –/120/60 where it passes through the rest of the building and no opening into it, and water supply and test drain pipes for fire services. NCC 2025 adds wiring and sensors for the stair's pressurisation system. Gas and other fuel services are banned from every required exit (D3D8(3)).
Did NCC 2025 change the fire safety rules behind these defects?
Not much. Every clause behind the eleven kept its number, and for these defects only three rules changed: D3D16 was rewritten around whether the doorway opens to an external space, C4D10 now also allows wiring and sensors for a stair's pressurisation system, and E1D2 accepts a hydrant system to AS 2118.6 or FPAA101H where they apply. Both editions call up the same editions of AS 1905.1, AS 4072.1, AS 1530.4 and AS 2419.1.
