When “Stay Put” Strategies Fail

The apartment fire that occurred in Valencia on 22 February 2024 has become one of the most significant high-rise residential fire events in recent years. Initial reports indicated that the fire originated on a balcony before rapidly spreading vertically and horizontally across the building façade, ultimately resulting in multiple fatalities and injuries. There are similarities between the Valencia fire and the horrific Grenfell Tower fire.

We have spoken long and often about the use of combustible cladding on apartment building facades, but in this article, we look at the “stay-put” strategy. (This is not to be confused with the “stay and defend” bushfire strategy.)

Understanding the Stay-Put Strategy

A stay-put strategy is an evacuation philosophy commonly adopted in high-rise residential buildings where occupants remote from the fire are expected to remain inside their apartment unless directly affected by smoke or instructed otherwise by emergency services.

From a fire safety engineering perspective, the strategy is fundamentally based on compartmentation. Modern high-rise apartment buildings are designed so that each sole-occupancy unit forms a fire-resisting compartment. Fire-rated walls, floors, doors, and protected service penetrations are intended to contain fire and smoke within the apartment of origin for a prescribed duration.

The engineering rationale is relatively straightforward:

• Contain the fire to the room or apartment of origin
• Prevent untenable smoke spread into common paths of travel
• Protect occupants not immediately threatened
• Maintain tenable conditions for firefighter intervention
• Avoid overloading evacuation stair capacity

This differs from buildings such as commercial offices or shopping centres, where simultaneous evacuation upon alarm activation is more common. In residential towers, simultaneous evacuation can create significant challenges, including stair congestion, delayed firefighter access, and increased exposure of occupants to smoke-filled common areas. Accordingly, many residential buildings globally, have historically adopted stay-put principles in some form.

Who Determines the Evacuation Philosophy?

The evacuation strategy for a building is generally established during the design phase and forms part of the broader fire safety engineering approach. This process typically involves fire safety engineers, architects, building designers, certifiers, fire authorities, building owners and operators.

In Australia, the strategy is typically developed in accordance with the National Construction Code (NCC), supported by performance-based fire engineering methodologies and the Australian Fire Engineering Guidelines.

Importantly, stay-put is not simply a management decision or operational preference. It is often embedded into the engineering assumptions of the building itself.

Why Stay-Put Strategies Have Historically Worked

From a statistical perspective, compartmentation-based residential fire safety has historically been highly successful. The vast majority of apartment fires remain confined to the apartment of origin. In sprinkler-protected buildings, the probability of extensive fire spread may be further reduced. In these cases, stay-put strategies can minimise unnecessary occupant movement and maintain safer conditions overall.

This approach has long been supported in countries such as the United Kingdom, where residential high-rise design evolved around robust masonry and concrete compartmentation systems. Similar principles have influenced residential fire engineering approaches internationally. However, the effectiveness of stay-put depends upon one critical assumption: the fire must behave within the design scenario.

This is where incidents such as Grenfell and Valencia become critically important.

The fire reportedly spread rapidly along the external façade, bypassing traditional internal compartment boundaries. Once fire propagates externally between levels, the original compartmentation strategy may become significantly compromised.

The NCC has requirements around compartmentation, fire resisting contraction, fire stopping, protected egress paths, smoke control, sprinkler protection, and firefighter intervention. Sprinkler systems, however, are also not designed to put out fires coming in from the outside of a building.

From a fire engineering perspective, façade-driven fire spread represents a fundamentally different problem to a conventional apartment compartment fire.

External fire spread can result in:

• Multiple simultaneous compartment breaches
• Rapid vertical flame propagation
• Re-entry of fire into remote apartments
• Toxic smoke production
• Fire spread beyond sprinkler coverage
• Collapse of defend-in-place assumptions

When this occurs, the available safe egress time (ASET) for occupants can reduce dramatically.

The Occupant Warning Problem

One of the most concerning aspects reported following the Valencia fire was that some occupants allegedly did not hear a building-wide fire alarm and delayed evacuation. Some reports suggested occupants relied upon verbal warnings or neighbours knocking on doors or visually seeing flames and smoke before evacuating. This issue directly intersects with stay-put philosophy.

Many residential buildings operating under stay-put principles do not activate general evacuation alarms immediately throughout the entire building during a single-compartment fire event. Instead, warning systems may initially notify only the affected apartment, adjacent units, or building management.

The engineering logic behind this is understandable when compartmentation remains intact. However, façade fires introduce a rapidly changing external threat that occupants may not initially perceive as affecting them directly.

The challenge is compounded by human behaviour research, which consistently demonstrates that occupants often delay action during emergencies while seeking confirmation, additional information, or social cues.

In fast-developing fires, those delays can become fatal.

A Fire Engineering Perspective

The Valencia apartment fire reinforces a critical principle within fire safety engineering: Evacuation strategies are only as reliable as the fire scenarios on which they are based.

Another critical factor is occupant knowledge and understanding of the building’s fire safety features. Building regulations may require fire protection systems to be installed, but they are ineffective if occupants don’t know where they are or how to use them.

Similarly, fire doors are designed to limit the spread of fire and smoke, but if occupants prop them open during a fire in an attempt to vent smoke, they unintentionally increase fire growth and compromise the building’s compartmentation strategy. The same issue extends fire-rated walls and ceilings which are designed to achieve a required fire resistance level, but subsequent unprotected penetrations for lighting, cabling or renovations can undermine their performance.

Stay-put policies are not inherently unsafe. In many buildings, they remain entirely appropriate and effective. Evacuation strategies must be carefully developed and tested against a range of credible fire scenarios, including sensitivity analyses that consider human behaviour and occupant response. There should always be a Plan B. Compliance does not always equal safety, and resilient fire safety design requires consideration of what happens when the original assumptions no longer hold true.