When does a building need a fire hydrant system in Australia?

Under NCC 2025 clause E1D2, any building with a total floor area over 500 m² needs a fire hydrant system, provided a fire brigade station is within 50 km by road and equipped to use hydrants. The system must comply with AS 2419.1:2021.

What flow rate and pressure do fire hydrants need under AS 2419.1?

Each fire hydrant outlet must deliver at least 10 litres per second (L/s) at a residual pressure of 200 kPa. The water supply must sustain this flow for a minimum of 4 hours (AS 2419.1:2021).

What is the maximum coverage distance for an internal fire hydrant?

Under AS 2419.1:2021, all parts of each floor must be within 40 metres hose run of an internal hydrant. This can increase to 45 metres where NCC Deemed-to-Satisfy travel distances are met. External hydrants cover up to 70 metres.

Are fire hose reels required in office buildings in Australia?

Class 5 office buildings are exempt from fire hose reel requirements under NCC 2025 E1D3(1)(a), along with Class 2, 3, and 9c (aged-care) buildings and Class 4 parts. Portable fire extinguishers are required instead. However, hose reels may still be needed where an internal hydrant is installed or the fire compartment exceeds 500 m².

What are the fire hose reel coverage requirements under AS 2441?

Each fire hose reel must cover a 40-metre radius (36 m standard hose length plus 4 m spray range) at a minimum flow of 0.33 L/s and 220 kPa running pressure. Reels must be placed within 4 metres of an exit (AS 2441-2005).

Fire Hydrant and Hose Reel Requirements

Section 1

What You Need to Know

Fire hydrants and hose reels protect buildings by giving firefighters and occupants water to fight fires. The NCC and AS 2419.1 set the rules for hydrants. AS 2441 covers hose reels. Any building over 500 m² in floor area needs a fire hydrant system. Get the layout, pipe sizing, or water supply wrong, and the system fails when it matters most.

Section 2

The Rules

Any building with a total floor area over 500 m² needs a fire hydrant system, if a fire station is within 50 km (NCC 2025, E1D2)
Each hydrant outlet must deliver at least 10 L/s at 200 kPa residual pressure (AS 2419.1:2021)
The water supply must last at least 4 hours at the design flow rate (AS 2419.1:2021)
All parts of each floor must be within 40 m hose run of an internal hydrant. This distance can increase to 45 m if NCC DTS travel distances are met (AS 2419.1:2021)
External hydrants cover up to 70 m hose run distance (AS 2419.1:2021)
Fire hose reels are exempt for Class 2, 3, and 5 buildings, Class 4 parts, and Class 9c aged-care buildings under E1D3(1)(a). Portable extinguishers are still required. DtS provisions may still require hose reels in Class 5 buildings where an internal hydrant is installed or the fire compartment exceeds 500 m² (NCC 2025, E1D3, E1D14)
Where hose reels are required, each reel must cover a 40 m radius (36 m hose + 4 m spray) at 0.33 L/s and 220 kPa (AS 2441-2005)

Section 3

What This Means in Practice

Take a three-storey Class 6 retail building with 2,400 m² total floor area. The NCC requires a fire hydrant system because the building exceeds 500 m². AS 2419.1 sets the layout. You need internal hydrants on every floor, spaced so that no point on the floor is more than 40 m hose run from a hydrant. That typically means one hydrant near each stairwell, plus extras on larger floor plates.

The water supply is the expensive part. The system needs 10 L/s per outlet for 4 hours. That means an on-site tank, a fire pump set, and a booster connection on the building facade for the fire brigade. Under AS 2419.1:2021, a booster is required when more than 2 feed hydrants are needed for coverage. The booster panel must sit within 20 m of the main entrance.

Hose reels follow a separate standard (AS 2441). Each reel covers a 40 m radius. Place reels within 4 m of an exit and along normal paths of travel. The supply pipe must be at least DN25 (25 mm). For a Class 5 office building, hose reels are not required under the NCC. Portable fire extinguishers cover that role instead.

Section 4

Key Design Decisions

1

Internal vs. External Hydrant Coverage

Use internal hydrants on every floor of multi-storey buildings. External hydrants alone only cover 4 levels above ground and 1 level below. Once internal hydrants are installed, external hydrants extend coverage to 2 levels above and 1 below. For buildings over 4 storeys, internal hydrants are not optional.

Trade-off: Internal hydrants add risers, valves, and hose cabinets on every floor. Budget $2,000 to $4,000 per hydrant point installed, plus the cost of the riser and ring main pipework.

2

Fire Pump and Water Supply Strategy

Size the fire pump for 10 L/s per outlet at 200 kPa at the most remote hydrant. Buildings over 25 m effective height need two pumps (duty and standby). A 4-hour supply at 10 L/s needs a 144,000 L (144 kL) tank if town mains cannot make up the flow.

Trade-off: A dedicated fire water tank takes up space at ground or basement level. Typical tank footprint is 6 m x 8 m x 3 m deep for 144 kL. Early coordination with the structural and hydraulic engineers avoids late-stage clashes.

3

Booster Location and Facade Coordination

AS 2419.1:2021 requires the booster within 20 m of the main pedestrian entrance. The booster panel sits in the building facade and takes up roughly 1.2 m x 0.6 m of wall space. Lock in the location during concept design so the architect can plan around it.

Trade-off: Moving the booster after the facade is designed costs time and money. A booster cabinet that clashes with shopfronts or entries is a common coordination failure.

4

Hose Reel Layout for Non-Exempt Buildings

For Class 6, 7, 8, and 9 buildings, map the 40 m coverage radius from each proposed reel location. Reels must sit within 4 m of an exit and must not be placed inside fire stairs. A typical 1,000 m² floor plate needs 2 to 3 reels for full coverage.

Trade-off: Each hose reel cabinet takes 600 mm x 300 mm of wall space near exits. Coordinate with the architect early so cabinet locations work with the interior layout.

Section 5

Who Needs to Know What

Section 6

References

AS 2419.1:2021, Fire hydrant installations — System design, installation and commissioning
AS 2441-2005 (reconfirmed 2018), Installation of fire hose reels
National Construction Code 2022, Volume One, Part E1 — Fire fighting equipment (E1D2, E1D3)
AS 2941-2013, Fixed fire protection installations — Pumpset systems
AS 1851-2012, Routine service of fire protection systems and equipment
Fire & Rescue NSW, Position Statement - Extended Fire Hydrant Coverage

Fire Hydrant and Hose Reel Requirements

What You Need to Know

The Rules

What This Means in Practice

Key Design Decisions

Internal vs. External Hydrant Coverage

Fire Pump and Water Supply Strategy

Booster Location and Facade Coordination

Hose Reel Layout for Non-Exempt Buildings

Who Needs to Know What

Need this engineered for your project?

References

Related design memos

Fire Sprinkler System Design for Commercial Buildings

Fire Sprinkler vs Fire Hydrant: When Each Is Required

Fire Sprinkler Head Spacing and Placement Rules