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Contents
  1. 1Terminology
  2. 2Place among evacuation strategies
  3. 3Conditions for staying in place
  4. 4Evidence from real fires
  5. 5Information, management and design
  6. 6Limits and risks
  7. 7See also
  8. 8Notes
  9. 9References

A stay-put strategy is an approach to a fire emergency in which occupants remain where they are, instead of leaving the building when the alarm sounds. Engineering guidance describes the same idea as "protect in place", "defend in place", "stay in place" or "shelter in place".[1][2][3] The International Fire Engineering Guidelines describe protect in place as a more recent development, used particularly in fully sprinklered residential buildings. Occupants are encouraged to remain where they are rather than escape through corridors or stairs that may be filled with smoke.[1]

Staying in place is only as safe as the place itself. In New Zealand, C/VM2 (second edition, 2025) requires such a place inside a building to be separated from the fire, protected by sprinklers and large enough for its occupants, with a way out.[4] Evidence from real fires shows both sides of the approach. In a fire in a 25-storey apartment building, almost half of the residents who tried to leave were turned back by smoke in corridors and stairs.[5] At the World Trade Center in 2001, advice to stay in place and await rescue was not the preferable course of action.[6]

Terminology

The sources group the strategy with several related ideas, and the names overlap. The International Fire Engineering Guidelines (IFEG, 2005) separate three approaches that differ from a traditional full evacuation. These are staged evacuation in high-rise buildings and hospitals, the fire safe refuge, and protect in place.[1] A fire safe refuge is a special fire compartment where occupants go to wait for rescue by the fire service, rather than evacuate.[1] In protect in place, occupants remain where they are.[1]

Other documents use "defend in place" in a wider sense. The design guidance of the Australian Building Codes Board speaks of "evacuation and / or defend in place strategies".[7] The NIST report on occupant behaviour at the World Trade Center calls a phased evacuation "also known as defend-in-place". In that scheme, occupants of the fire floor and the floors around it go down to three floors below the fire, while everybody else stays.[8] The SFPE Handbook chapter on detection systems lists "stay-in-place or defend-in-place strategies" next to partial evacuation and relocation strategies.[2] In the narrow sense used in this article, a stay-put strategy keeps most occupants where they are, while a phased evacuation moves floors out in a planned order.

Place among evacuation strategies

A stay-put strategy is one of the options in a building's evacuation strategy, the plan that states who leaves, when and by which route. The IFEG notes that traditional practice has been to start evacuating occupants in response to fire alarms, following an evacuation management plan.[9] In high-rise buildings with emergency warning and intercommunication systems, trained personnel may manage the evacuation. Floors furthest from the fire are first put on alert and are evacuated progressively only if the fire continues to develop.[1] In hospitals, nursing staff first move patients horizontally to an adjacent smoke zone or fire compartment. Patients are moved further only if the threat keeps growing.[1]

Staying put is thus the far end of a scale that runs from full evacuation through staged and horizontal movement. The IFEG itself is limited to designs in which occupants are evacuated to a place of safety. It describes the newer occupant management concepts as "still developing".[9] Some occupants cannot leave at all without help. Iqbal and Salley note that the US model building codes place much stricter requirements on institutional occupancies, such as hospitals, nursing homes and penal institutions. A defend-in-place strategy is necessary there because the occupants cannot flee the structure without assistance.[10]

Horizontal scale with five building icons, from full evacuation on the left to protect in place on the right.
Evacuation approaches described in the guidance, from moving everybody out to keeping occupants where they are. Based on National Research Council of Canada et al. (2005), pp. 1.8-2 and 2.8-2.

Conditions for staying in place

A person can only stay safely where fire and smoke cannot reach for the whole duration of the fire. This is why the strategy rests on fire compartmentation: the division of a building into separate fire compartments. In the Netherlands, the sub-goals behind the building regulations include maintaining compartmentation, limiting the spread of fire and smoke, and keeping escape routes usable.[11] The New Zealand Verification Method C/VM2 (second edition, 2025) states the conditions most precisely. A place of safety inside a building must meet four requirements:[4]

  • its fire separations have enough fire resistance to withstand burnout at the point of the fire source;
  • the building is protected by an automatic sprinkler system complying with NZS 4541 or NZS 4515;
  • the place is designed for the intended number of persons;
  • it has enough means of escape for those persons to reach a safe place outside the building.

The first condition means that the walls and floors around the waiting place must hold until the fire has consumed all its fuel. The second condition matches the IFEG remark that protect in place is used particularly in fully sprinklered residential buildings.[1] The fourth condition keeps a way out open in case the situation changes.[4]

Cross-section of three floors with a burning flat, fire-resisting walls and floors, sprinkler heads, residents in a neighbouring flat and a protected stair.
Conditions for a place of safety inside a building in New Zealand's C/VM2 (second edition, 2025), shown for a flat where residents stay during a fire elsewhere. Based on Ministry of Business, Innovation and Employment (2025b), p. 68.

Smoke is the second threat. Introduction to Fire Safety Engineering reports Dutch tests in residential buildings in which carbon monoxide concentrations far from the fire were very high while visibility was still more than 20 m.[12] The reason is that soot particles settle and travel less far through a building than the gases do.[12] A corridor that looks clear can therefore still be dangerous. This matches the reasoning of the IFEG, in which occupants stay rather than pass through corridors or stairs that may be filled with smoke.[1]

Evidence from real fires

Studies of fires in high-rise residential buildings show why moving through a building can be riskier than staying. Proulx surveyed the residents of a 25-storey apartment building after a fire, with 137 questionnaires returned. Of those residents, 68 % were over 60 years of age.[5]

In total, 114 occupants (83 %) tried to evacuate, and 96 of them (84 %) moved through smoke.[5] Only 61 of the 114 succeeded. The other 53 were stopped by smoke in the corridors or stairs. Of these, 29 went back to their own apartments and 24 sought refuge in other apartments.[5]

Stacked bars: of 114 residents who tried to leave, 61 succeeded, 29 returned to their own flat and 24 sheltered in another flat.
Outcome for the 114 residents who tried to evacuate during a fire in a 25-storey apartment building. Based on Proulx (1998), as cited in Bryan (2002), pp. 3-334–3-335.

In two high-rise residential fires in Canada studied by Proulx, six people died in stairwells in one case and one person died in the suite of origin in the other.[13] In the first fire, the alarm was not audible in many apartments, and residents learned of the fire from others. In the second, every suite had a sounder and occupants waited for instructions from the voice communication system.[13] In a night-time high-rise residential fire studied by Brennan, only about half the occupants actually evacuated.[14]

Occupants also choose to stay of their own accord. Hall and Ahrens point out that occupants may defend in place when they should not, or evacuate when staying would be safer. They stress that neither is panic or irrational behaviour, but a realistic picture of how people respond to fire.[15] Bryan describes "convergence clusters", in which occupants gather in particular rooms that they select as refuges.[16]

In the MGM Grand Hotel fire, guests gathered in rooms with balconies because these offered ventilation, less smoke, better visibility and a way to communicate.[16] The clusters held between 3 and 35 people. They usually lasted until help arrived or until fire or rescue personnel told the occupants to leave.[16]

Information, management and design

A stay-put strategy relies on information reaching the occupants. Schifiliti, Meacham and Custer note that in stay-in-place, defend-in-place and partial evacuation strategies, the detection system does more than raise an alarm. It provides information about the location and extent of the fire, after which instructions are given to the people concerned.[2]

A drill in a 21-storey office building in Ottawa in 1971 shows how much this depends on the people giving the instructions. The selective procedure could have ended after 6 minutes, once the presumed fire floor and two adjacent floors were cleared.[17] However, a wrongly set switch delayed the first announcement. The message that followed, "Please evacuate. Other floors stand by", was ambiguous.[17]

In Australia, the Fire Safety Verification Method (FSVM) requires the fire safety strategy to pay particular attention to the evacuation strategy and the management regimes it needs.[18] The FSVM handbook asks that the report of the performance-based design brief describe the evacuation and defend-in-place strategies for all people. It must also describe how these will remain effective throughout the life of the building.[7] For an ultra-high-rise building, the handbook lists additional protect-in-place and partial evacuation strategies among the enhancements that may be appropriate.[19]

In New Zealand, C/VM2 (second edition, 2025) has a short section on "delayed evacuation strategies". Buildings whose occupants are required to stay in place, or are evacuated to a place inside the building, must meet the definition of a place of safety.[3] The examples given are people who are detained or who are undergoing treatment, such as in an operating theatre, a hyperbaric chamber or a dialysis unit.[3] A comment in C/VM2 adds that such spaces usually have climate control, so smoke detection and the smoke control of the air handling system need special care.[3]

Limits and risks

Guidance names several situations in which the strategy may not work as planned. The Australian data sheets warn that phased evacuation strategies may be sensitive to rapid fire spread over several floors through the outside wall, a facade fire.[20] Depending on the building, this scenario may need to be analysed, and the strategy should state what to do when fire spreads quickly to several floors.[20] The same data sheets require a check of the design in which the automatic alarm or intercommunication system fails.[20] In small and medium-sized multi-residential buildings, alarms are often simple and the emergency organisation informal, so occupant behaviour varies more.[20]

At the World Trade Center in 2001, stay-in-place advice did not match the situation. Emergency dispatchers and 9-1-1 operators generally told occupants to shelter in place and await rescue. This was in line with existing protocols, but it was not the preferable course of action that day.[6] Information about where the aircraft had struck was generally not passed on to trapped occupants.[21] Simulations by NIST showed that a phased evacuation of the fire floor and the floors around it would have taken 4 to 11 minutes. A full evacuation of a tower with 19,800 occupants would have taken 92 to 112 minutes.[8]

After the investigation, NIST recommended that occupants be trained for a range of scenarios, including both evacuation and shelter in place. It also recommended that tall buildings be designed for timely full evacuation when needed.[22] NIST noted that current strategies and laws generally require occupants with reduced mobility to shelter in place and await assistance. It recommended giving them a means of self-evacuation where possible, for example protected lifts.[23] NIST also found it difficult to predict how long people would be willing to wait in a refuge area before entering a stair.[23]

See also

Notes

  1. ↑ 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 National Research Council of Canada et al. (2005), p. 2.8-2.
  2. ↑ 2.0 2.1 2.2 Schifiliti et al. (2002), p. 4-2.
  3. ↑ 3.0 3.1 3.2 3.3 Ministry of Business, Innovation and Employment (2025b), p. 34.
  4. ↑ 4.0 4.1 4.2 Ministry of Business, Innovation and Employment (2025b), p. 68.
  5. ↑ 5.0 5.1 5.2 5.3 Proulx (1998), as cited in Bryan (2002), pp. 3-334–3-335.
  6. ↑ 6.0 6.1 Averill et al. (2005), p. 108.
  7. ↑ 7.0 7.1 Australian Building Codes Board (2020b), p. 117.
  8. ↑ 8.0 8.1 Averill et al. (2005), p. xxxv.
  9. ↑ 9.0 9.1 National Research Council of Canada et al. (2005), p. 1.8-2.
  10. ↑ Iqbal and Salley (2004), p. B-33.
  11. ↑ Van Rossum (2027), §1.2.
  12. ↑ 12.0 12.1 Brandweeracademie (2020), as cited in Van Rossum (2027), §6.1.
  13. ↑ 13.0 13.1 Proulx (2002), p. 3-349.
  14. ↑ Brennan (1998), as cited in Proulx (2002), p. 3-349.
  15. ↑ Hall and Ahrens (2002), p. 5-74.
  16. ↑ 16.0 16.1 16.2 Bryan (2002), p. 3-328.
  17. ↑ 17.0 17.1 Proulx (2002), p. 3-358.
  18. ↑ Australian Building Codes Board (2022), p. 7.
  19. ↑ Australian Building Codes Board (2020b), p. 49.
  20. ↑ 20.0 20.1 20.2 20.3 Australian Building Codes Board (2020a), p. 250.
  21. ↑ Averill et al. (2005), p. 145.
  22. ↑ National Institute of Standards and Technology (2005), p. 215.
  23. ↑ 23.0 23.1 National Institute of Standards and Technology (2005), p. 216.

References

  • Australian Building Codes Board. (2020a). Data sheets: Fire Safety Verification Method (Handbook annex, Print version 1.1).
  • Australian Building Codes Board. (2020b). Handbook: Fire Safety Verification Method (Print version 1.1).
  • Australian Building Codes Board. (2022). Fire Safety Verification Method Standard 2022.
  • Averill, J. D., Mileti, D. S., Peacock, R. D., Kuligowski, E. D., Groner, N., Proulx, G., Reneke, P. A., & Nelson, H. E. (2005). Occupant behavior, egress, and emergency communications (NIST NCSTAR 1-7). National Institute of Standards and Technology.
  • Bryan, J. L. (2002). Behavioral response to fire and smoke. In P. J. DiNenno, D. Drysdale, C. L. Beyler, W. D. Walton, R. L. P. Custer, J. R. Hall Jr., & J. M. Watts Jr. (Eds.), SFPE handbook of fire protection engineering (3rd ed., pp. 3-315–3-341). National Fire Protection Association; Society of Fire Protection Engineers.
  • Hall, J. R., Jr., & Ahrens, M. J. (2002). Data for engineering analysis. In P. J. DiNenno, D. Drysdale, C. L. Beyler, W. D. Walton, R. L. P. Custer, J. R. Hall Jr., & J. M. Watts Jr. (Eds.), SFPE handbook of fire protection engineering (3rd ed., pp. 5-65–5-78). National Fire Protection Association; Society of Fire Protection Engineers.
  • Iqbal, N., & Salley, M. H. (2004). Fire Dynamics Tools (FDTs): Quantitative fire hazard analysis methods for the U.S. Nuclear Regulatory Commission Fire Protection Inspection Program (NUREG-1805). U.S. Nuclear Regulatory Commission, Office of Nuclear Reactor Regulation.
  • Ministry of Business, Innovation and Employment. (2025b). Verification Method C/VM2: Framework for fire safety design (2nd ed.).
  • National Institute of Standards and Technology. (2005). Final report on the collapse of the World Trade Center towers (NIST NCSTAR 1).
  • National Research Council of Canada, International Code Council, Department of Building and Housing, & Australian Building Codes Board. (2005). International fire engineering guidelines (2005 ed.). Australian Building Codes Board.
  • Proulx, G. (2002). Movement of people: The evacuation timing. In P. J. DiNenno, D. Drysdale, C. L. Beyler, W. D. Walton, R. L. P. Custer, J. R. Hall Jr., & J. M. Watts Jr. (Eds.), SFPE handbook of fire protection engineering (3rd ed., pp. 3-342–3-366). National Fire Protection Association; Society of Fire Protection Engineers.
  • Schifiliti, R. P., Meacham, B. J., & Custer, R. L. P. (2002). Design of detection systems. In P. J. DiNenno, D. Drysdale, C. L. Beyler, W. D. Walton, R. L. P. Custer, J. R. Hall Jr., & J. M. Watts Jr. (Eds.), SFPE handbook of fire protection engineering (3rd ed., pp. 4-1–4-43). National Fire Protection Association; Society of Fire Protection Engineers.
  • Van Rossum, E. (2027). Introduction to Fire Safety Engineering. Fire Safety Academy.
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