How Passive Fire Systems Differ from Active Fire Systems
May 16, 2025
Picture yourself enjoying a sunny afternoon at your favourite café in Perth or settling into a cosy movie night at home in Hobart—safe, sound, and blissfully unaware of the hidden safety measures at work. Yet behind every wall and ceiling in our Australian homes and workplaces, a silent partnership exists between two types of fire protection: passive and active systems. While active systems—those instantly recognisable sprinklers, alarms, and fire hose reels—leap into action during an emergency, passive systems are the unsung heroes, built right into the structure to resist fire’s advance.
In Australia, both approaches are mandated by the National Construction Code and Australian Standards to buy valuable evacuation time and protect lives. Let’s dive into the key differences between these two approaches, and discover how their combined strength keeps Australians safe—quietly guarding us until the sprinklers ever need to flow.
Key Differences Between Passive and Active Fire Protection
So, what really sets passive fire protection and active fire protection apart? Let’s break down their fundamental roles, the materials that make them work, and the compliance pathways you need to know under Australia’s NCC and Standards.
Fundamental Functionality
Passive Fire Protection (PFP)
Containment overreaction: Integrated into the building’s fabric, PFP materials and assemblies are engineered to resist fire spread for a specified period (e.g., 60 or 120 minutes).
Always on, always ready: No reliance on power or sensors—ideal when storms or bushfire conditions knock out electricity.
Active Fire Protection (AFP)
Detection and response: Mechanical and electrical systems (sprinklers, alarms, gas suppression) activate the moment they sense heat, smoke, or flame.
Immediate intervention: Designed to suppress or alert occupants once a fire has already started.
Key Components and Materials
Passive Fire Protection Elements
Fire‑resistant walls and floors
Constructed from fire‑rated plasterboard or masonry, these elements form the first line of compartmentation—buying you 60, 90, or even 120 minutes to escape.
Intumescent sealants and strips
Hidden around every cable, duct, and door frame, these clever materials swell under heat to seal gaps and block smoke and flames.
Self‑closing fire doors and shutters
Always on guard, these doors automatically swing or drop shut as soon as the alarm sounds—or the heat hits—keeping compartments intact.
Active Fire Protection Systems
Sprinkler systems
Commonly wet‑pipe or dry‑pipe in Australia; designed to discharge water directly onto flames when a fusible link or glass bulb reaches its activation temperature.
Smoke and heat detectors
Installed in accordance with AS 1670.1, triggering alarms and, in some cases, interfacing with sprinklers or gas suppression.
Portable and fixed extinguishers
Strategically located, often in accordance with AS 2444, to tackle small fires before they escalate.
Design and Installation Considerations
Getting passive and active systems to work seamlessly takes careful planning and clear communication. But why does every millimetre matter so much?
Early PFP Design
Architects, fire engineers, and builders must agree on compartment lines before framing even starts.
Sketching fire‑rated walls into your floor plan early prevents last‑minute clashes with pipes or cables.
AFP Installation
Specialist contractors install sprinklers and detectors to strict spacing rules (see AS 2118 and AS 1670).
Co‑ordinate with electricians and plumbers—those tiny bends or extra joints can block a sprinkler’s spray.
Maintenance, Inspection, and Testing
Passive Systems
Visual inspections: Conduct quarterly checks on seals, door closers, and integrity of fire‑resistant partitions.
Periodic certification: Every 2–3 years, engage fire‑safety inspectors to verify that PFP components remain compliant under AS 1851 (maintenance standard).
Active Systems
Monthly and annual servicing: Sprinkler tests, detector sensitivity checks, and alarm system drills in line with AS 1851.
Record‑keeping: Detailed logs of all inspections and remedial works must be maintained for regulatory audits.
Regulatory Framework and Compliance
National Construction Code (NCC)
Establishes minimum performance standards for both passive (e.g., compartmentalisation) and active (e.g., sprinkler coverage) measures.
Australian Standards
AS 1530 series for fire‑resistance testing (PFP).
AS 2118 for design and installation of sprinkler systems (AFP).
AS 1670 and AS 2444 for fire detection and extinguisher placement.
Bushfire-Prone Areas
Additional requirements under BAL (Bushfire Attack Level) ratings may dictate enhanced PFP materials (e.g., fire‑resistant external cladding) and AFP considerations (e.g., water supply capacity for sprinklers).
Why You Can’t Rely on Active Systems Alone
While active fire protection systems—sprinklers, alarms, and extinguishers—are indispensable for suppressing a blaze once it starts, they have inherent limitations. In the uniquely Australian context of extreme bushfire risk, tropical storms, and ageing building stock, passive measures are essential back‑up. Here’s why active systems by themselves aren’t enough:
Potential Points of Failure
Power and Water Supply Vulnerabilities
Electrical outages: During severe storms or bushfire-induced damage, power can be cut, rendering pumps, detectors, and alarms inoperative.
Water mains disruptions: Drought conditions or firefighting demand can strain public supply; dry‑pipe systems may fail if water isn’t available.
Mechanical Malfunctions
Sprinkler heads can corrode, clog, or be accidentally painted over during renovations.
Smoke detectors may drift out of calibration, reducing sensitivity over time.
Human Error
Portable extinguishers sometimes get moved, blocked, or expire unnoticed.
False alarms or nuisance activations may lead occupants to ignore genuine alerts.
Reactive vs. Proactive Protection
Passive systems act before fire growth becomes critical—whereas active systems only engage once fire or smoke is already present.
Containment vs. Suppression
Passive containment:
Fire‑rated walls and doors restrict the spread of heat and smoke, protecting escape routes and limiting property damage.
Active suppression:
Sprinklers and extinguishers aim to knock down flames after ignition—a reactive approach that can never address all scenarios (e.g., deep‑seat fires in concealed spaces).
Continuous vs. Conditional Performance
Always‑on resilience
Passive components require no activation threshold; they maintain their resistance even when undisturbed.
Conditional operation
Active systems only function once triggered; if detection or activation fails, there’s no layer of defense.
Regulatory Incentives for Layered Protection
NCC Performance Requirement CP2
Mandates that buildings provide alternative safety measures if active systems might be compromised under credible scenarios (e.g., power loss).
Bushfire Attack Level (BAL) Ratings
At BAL‑40 and BAL‑FZ, enhanced passive measures—such as non‑combustible roofing and sealed external gaps—are compulsory, recognising that reliance on water‑based suppression alone is insufficient.
How Passive and Active Systems Work Together in Fire Safety Design
In Australia’s multifaceted fire environment—from dense urban centres to bushfire‑prone regional areas—an integrated fire safety strategy is essential. Passive and active systems aren’t standalone solutions; they form a coordinated defence that maximises protection, compliance, and occupant safety.
Integrated Design Approach
Early Collaboration
Architects, fire engineers, and services consultants work together at concept stage to balance compartmentation (passive) with sprinkler coverage and detection zones (active).
BIM (Building Information Modelling) tools help visualise fire zones, pipe runs, and seal locations, reducing clashes on site.
Performance‑Based Design
Under the NCC’s performance provisions, designers can tailor solutions—perhaps enlarging fire compartments in a bushfire‑rated home while optimising sprinkler head density in communal corridors.
Layered Defence Strategy
Compartmentation + Suppression
Fire‑rated walls and doors create safe zones and escape paths.
Sprinklers in corridors and occupied spaces suppress flames that breach a compartment, preventing reignition and reducing smoke production.
Sealing + Detection
Intumescent seals around penetrations stop smoke migration.
Smoke detectors trigger alarms and pressurise stairwells, keeping exit routes clear of toxic gases.
Evacuation and Life‑Safety Integration
Clear Egress
Passive systems ensure exits remain structurally sound long enough for evacuation.
Active voice‑alarm systems guide occupants with clear instructions, even in noisy or smoke‑filled environments.
AS 1851 requires different schedules: visual checks of seals and doors versus functional tests of sprinklers and alarms.
Integrated logbooks track both passive integrity and active performance, ensuring no component is overlooked.
Training and Drills
Facility managers run combined fire drills, testing alarms, sprinkler response, and the ability of doors to close automatically—reinforcing the synergy of both systems.
Compliance and Certification Risks of Overlooking Passive Fire
Australia’s stringent fire‑safety regime leaves no room for cutting corners—especially when it comes to passive fire protection. Overlooking these built‑in, structural safeguards can trigger a cascade of regulatory, financial, and legal headaches that ripple throughout a project’s lifecycle. Below, we delve into the key compliance and certification risks you face when passive fire measures are neglected on Australian sites.
Regulatory Non‑Compliance
Passive fire protection is embedded in the very performance requirements of the National Construction Code (NCC) and a suite of Australian Standards. Skipping or undervaluing these measures almost guarantees non‑compliance.
NCC Volume One, Section C Breaches
Fire‑Resistance Level (FRL) shortfalls: If a wall, floor or door doesn’t meet its specified Fire‑Resistance Level (e.g. 90/90/90), it can’t form a valid compartment—and your certifier will flag it immediately.
Compartment overruns: Skipping a required fire‑rated partition enlarges the fire cell beyond NCC limits, voiding your performance solution.
Australian Standards Violations
AS 1530.4 omissions:Without certified fire‑resistance test reports for materials, certifiers have no evidence that assemblies perform as claimed.
AS 4072.1 sealant lapses: Gaps around services and penetrations must be filled with intumescent seals tested and installed per this standard, or smoke and flame will exploit weak points.
State‑Specific Certification Triggers
In New South Wales, certifiers under the Environmental Planning and Assessment Act require documented evidence of passive systems before issuing Complying Development Certificates.
Victoria’s Building Regulations 2018 demand Passive Fire Compliance Reports for class 2 buildings exceeding three storeys—failure to produce these delays occupancy.
Certification Delays and Budget Overruns
When passive fire protection is treated as an afterthought, the approval process stalls—and costs skyrocket.
Protracted Approval Timelines
Fire engineers and certifiers issue Non‑Conformance Notices (NCNs), forcing redesign and re‑submission. Each round can add 4–6 weeks to the program.
Occupancy Permits withheld: Until passive elements are verified, building owners cannot lawfully occupy the space, impacting tenant fit‑outs and revenue streams.
Retrofit and Remediation Expenses
Retrofitting fire‑rated walls or intumescent coatings into a live site can be up to five times more expensive than initial installation, due to access, protection of finishes, and out‑of‑hours work.
Specialist trades and third‑party inspectors command premium rates—often 1.5× standard labour costs—to resolve non‑compliance swiftly.
Hidden Lifecycle Costs
Ongoing inspection fees: Passive systems require periodic certification under AS 1851; missed initial compliance can lead to more frequent—and costly—re‑inspections.
Warranty invalidation: Many manufacturers’ warranties on fire doors and sealants become void if products aren’t installed per their Evidence of Suitability (EoS) documentation.
Legal Liability and Insurance Exposure
When a fire incident reveals that passive protection was inadequate, the repercussions extend far beyond fines.
Civil and Criminal Liability
Negligence claims: Occupants or owners can sue builders, designers, and certifiers if inadequate passive measures contribute to property damage or injury.
Regulatory prosecution: Under state building acts (e.g., Queensland’s Building Act 1975), serious breaches can attract fines up to six figures or even director bans.
Insurance Claim Rejection
Post‑fire investigations by insurers often scrutinise Passive Fire Compliance Certificates; any gaps, damaged seals, or non‑certified products can void cover for fire damage.
Increased premiums: Even if claims are paid, insurers may hike premiums substantially for buildings deemed “high‑risk” due to poor passive protection.
Reputation and Occupant Safety Impact
Beyond the bottom line, skipping passive fire measures damages your professional standing—and, most critically, puts lives at risk.
Brand and Credibility Damage
Publicised audit failures or non‑compliance notices tarnish reputations of architects, builders, and certifiers, making it harder to win future projects.
Client trust erodes when safety deficiencies emerge, potentially leading to contract terminations or legal disputes.
Compromised Life‑Safety
Without proper compartmentation, smoke and flames spread rapidly, blocking escape routes and overwhelming active systems.
Fire‑rated doors that don’t close or seals that have degraded leave occupants with far less time to evacuate—locking in unacceptable risk.
When to Engage a Passive Fire Specialist
Ensuring robust passive fire protection starts well before the first brick is laid. Engaging a qualified passive fire specialist at the right stages of your project not only streamlines compliance with Australia’s National Construction Code (NCC) and relevant Australian Standards, but also saves time, money, and—most importantly—lives. Below are the key moments when you should bring in the experts.
During Early Design and Concept Development
Incorporating passive fire strategies from the outset avoids costly redesigns later.
Collaborative Masterplanning
Work with architects and fire engineers to define fire compartments, escape zones, and material selections in your concept sketches.
Use performance‑based modelling (e.g., fire‑engineered solutions under NCC Performance Requirement CP1) to optimise compartment sizes and reduce unnecessary fire-rated area.
Material and System Selection
Evaluate intumescent coatings, fire‑resistant boards, and sealant systems early to ensure structural compatibility and availability—especially critical in bushfire‑prone regions where specialised products may be in high demand.
Assess façade and cladding options for BAL‑rated sites to meet Bushfire Attack Level requirements.
Before Construction Commences (Pre‑Tender Stage)
Locking in passive fire details in your tender documents ensures clarity for all trades.
Preparation of Fire‑Compliance Documentation
Commission fire‑resistance test reports (per AS 1530.4) and Evidence of Suitability certificates for each assembly.
Specify fire‑sealed penetration details (AS 4072.1) and door schedules (including self‑closers and hardware) in your construction drawings.
Trade Coordination Workshops
Convene pre‑construction meetings led by the passive fire specialist to clarify installation sequences, penetration zones, and inspection points.
Identify potential clashes between services (e.g., electrical conduits, plumbing stacks) and fire barriers early, avoiding on‑site rework.
During Construction and Fit‑Out
On-site oversight guarantees that passive elements are installed correctly the first time.
Regular Site Inspections
Schedule inspections at critical milestones: after wall framing, before services penetration, and prior to linings being installed.
Verify that intumescent sealants are applied to the correct depth and width, and that fire‑rated doors are hung and operate smoothly.
Issue Resolution and Reporting
Address Non‑Conformance Notices (NCNs) immediately, with the specialist providing corrective actions and re‑inspection.
Maintain a compliant logbook in accordance with AS 1851, documenting all site observations and sign‑offs.
For Refurbishments, Alterations, and Change of Use
Existing buildings often harbour hidden fire‑safety gaps that only a specialist can uncover.
Compliance Audits
Engage the specialist to conduct a passive fire audit, revealing breaches in compartmentation, degraded seals, or missing fire doors.
Audit criteria should reference NCC Verification Methods and state‑specific building regulations (e.g., Victoria’s Building Amendment Act).
Upgrade and Retrofit Strategies
Develop cost‑effective retrofit packages—such as cavity barriers behind new joinery or upgrading to intumescent‑rated electrical boxes—to bring the building up to current code without full-scale demolition.
Coordinate with heritage or strata requirements where alterations may affect character or shared assets.
Prior to Occupancy and Certification
Final sign‑off by certifiers hinges on complete and correct passive fire documentation.
Certification Package Assembly
Have the passive fire specialist collate all test certificates, installation reports, and “as‑built” door schedules for submission to the building surveyor or accredited certifier.
Ensure that all products installed match those listed in the Evidence of Suitability and manufacturer’s specifications.
Final Functional Checks
Carry out walk‑through testing of self‑closing doors, visual verification of seal integrity around penetrations, and confirm fire‑rating labels are in place.
Provide the client with maintenance guidelines and schedules to uphold passive fire performance over the building’s lifecycle.
Achieving Total Fire Protection
True resilience against fire hazards comes from weaving together passive, active, and administrative measures into a single, cohesive strategy. In Australia’s varied environments—from cyclone‑prone Queensland to bushfire‑vulnerable Western Australia—this “total fire protection” approach ensures buildings perform under every conceivable scenario.
Holistic Fire Safety Planning
A robust fire‑safety plan considers every stage of a building’s lifecycle and every potential risk source.
Risk Assessment & Zoning
Map out fire‑hazard zones (e.g., kitchen areas, plant rooms, bushfire‑prone exteriors) and assign appropriate Bushfire Attack Level (BAL) ratings where necessary.
Use performance‑based analysis (NCC Performance Requirements CP1–CP4) to tailor solutions rather than relying solely on generic solutions.
Integrated Design Brief
Engage architects, fire engineers, and building services consultants together to draft a brief that balances functionality, aesthetics, and layered fire safety.
Include passive details (compartmentation lines, door schedules) and active requirements (sprinkler head layouts, detector coverage) in early drawings.
Layering Passive and Active Defences
Combining the strengths of both systems yields a “belt‑and‑braces” configuration.
Passive Foundations
Fire‑resistant walls, floors, and structural elements with specified FRLs (e.g., 120/120/120) per AS 1530.4.
Intumescent seals and fire‑rated glazing around all penetrations and openings, following AS 4072.1.
Self‑closing fire doors and shutters to maintain compartment integrity.
Active Safeguards
Sprinkler systems designed to AS 2118 standards, with dedicated water supplies sized for worst‑case demand scenarios.
Fire detection and alarm systems per AS 1670.1, linked to emergency warning devices and building management systems.
Portable and fixed fire extinguishers (AS 2444) positioned at strategic intervals.
Administrative and Operational Controls
Technical measures must be backed by clear policies, training, and maintenance regimes.
Maintenance Regimes
Implement AS 1851 schedules: quarterly visual checks of passive elements and monthly/annual servicing of active systems.
Maintain comprehensive logbooks—digital or hardcopy—detailing all inspections, defects, and remedial actions.
Training & Emergency Procedures
Conduct regular fire drills that test alarms, evacuation routes, and the closure of fire doors under real‑world conditions.
Provide occupants and facility managers with clear emergency response plans, including contact details for local fire services and passive system specialists.
Regulatory Compliance & Continuous Improvement
Staying ahead of evolving codes and technologies ensures long‑term protection.
Ongoing Code Review
Monitor updates to the National Construction Code and Australian Standards (e.g., revisions to AS 1530 or AS 2118) and implement changes during planned maintenance windows.
Audit & Certification
Engage accredited certifiers at key milestones: design sign‑off, pre‑occupancy certification, and periodic re‑certification for high‑risk buildings.
Use third‑party audits to benchmark performance against industry best practices and identify opportunities for enhancement.
As you sip your morning cuppa by the Harbour or unwind under Melbourne’s starry skies, take comfort knowing that both passive fire barriers and active suppression systems are quietly working together to protect you. By combining fire‑resistant walls, doors, and intumescent seals with sprinklers, alarms, and detectors that meet the National Construction Code and Australian Standards, you ensure your home or workplace is ready for anything—from sudden electrical faults to bushfire embers.
