Inside Risk: Sprinkler protection in enclosed parking structures

The property fire risk of cars and associated enclosed parking areas has changed significantly over recent decades, increasing the risk of a large loss. Many modern vehicles have increased in size and incorporate bigger quantities of combustible materials such as plastics and other synthetic materials. New vehicle technologies have introduced innovative fuel sources such as electric batteries which can change the burning characteristics and required firefighting strategies. The design of parking garages has also changed, introducing features such as sloped floors or technology to increase parking capacity such as car stackers.

These changes increase the need for a robust fire protection strategy to safeguard life, property, and the environment. Sprinklers are a proven and effective technology to mitigate the risk of fire and this Inside Risk summarize some of the property features that need considering when installing sprinklers in parking garage areas.

Recent losses:

Several large fires have highlighted the potential for a significant fire loss within a parking garage. In addition to the damage to vehicles and building structure, there is also the potential loss of revenue and disruption as well as impacts to life and environment.

Lisbon Airport (August 2024) (opens a new window): a significant fire broke out near Lisbon Humberto Delgado Airport in Portugal and destroyed more than 200 vehicles. Initial media reports have linked the blaze to an electric car catching fire, but this has not been confirmed by officials.

San Diego, Kettner Boulevard (March 2024) (opens a new window): three hybrid airport-shuttle vehicles were damaged after a lithium-ion battery ignited in a parking structure. In this case, the fire activated sprinklers installed in the building. Firefighters said it took about 30 minutes to extinguish the fires.

Luton Airport (Oct 2023) (opens a new window): a large fire occurred in a multistory parking garage at Luton Airport. Initially starting in a moving diesel vehicle, the fire spread and destroyed around 1400 cars. The parking garage was not sprinklered. The Fire & Rescue Service significant incident report (opens a new window) concluded “If a suitable sprinkler system had been installed, it may have changed and delayed the pattern of fire spread increasing the chances of a successful outcome once firefighting operations had begun.”

Kings Dock, Liverpool (Dec 2017) (opens a new window): a vehicle fire occurred on the third floor of an 8-level open-sided parking garage. The fire spread, aided by the parking garage drainage systems, resulted in the loss of around 1150 vehicles together with extensive damage to the building fabric. The parking garage was not sprinklered.

Monica Wills House, Bristol (Dec 2006) (opens a new window): a fire occurred in an underground parking garage area of a residential care home. The fire destroyed twenty-two cars and spread to upper levels via windows. One person died and sixty residents were evacuated.

Gretzenbach, Switzerland (Nov 2004) (opens a new window): a fire occurred in an underground parking garage, resulting in the death of seven firefighters and the collapse of a housing block.

The installation of an acceptable fire sprinkler system can help reduce the risk of fire spreading within the parking garage area, reducing the size of the loss and assisting the fire service to achieve final extinguishment.

Property insurer assessments – loss estimates and risk quality

When assessing property fire risk, insurers look beyond regulatory compliance (such as compliance with Building Regulations in England) to consider property and business resilience. Compliance with life safety regulations does not necessarily mean the building would be considered resilient to fire or other perils. Developers or building owners should consider if it is sufficient to ensure safe means of evacuation (but with potential loss of the building in a fire event) or if the fire loss should also be minimized through robust construction and fire-protection measures such as sprinklers to enable ‘business as usual’ following a fire incident. The former would be considered less favorably by property insurers than the latter, potentially impacting insurer appetite, premium or other conditions.

Loss estimates: Property risk engineers typically develop one or more loss estimates for insurers when assessing large properties. These loss estimates can impact premium, capacity or risk quality assessments. A sprinklered parking garage which meets insurer requirements can reduce the insurer’s ‘normal loss expectancy’ (NLE) for the property and consequently be viewed more favorably by underwriters, helping to improve insurance terms and conditions at renewal. If a parking garage is not sprinklered, or if the sprinklers do not meet insurer requirements, the NLE can increase, potentially approaching the insurers ‘maximum foreseeable loss’ (MFL). Loss estimate terminology (such as NLE and MFL) and methodologies vary by insurer.

Risk quality: When assessing risk, insurers consider a range of features including building construction (e.g. combustible vs non-combustible), occupancy (e.g. hazards present), protection (e.g. sprinklers, detection, and management controls) and exposures (e.g. external hazards surrounding the premises). Of all these features, the presence of reliable and adequate sprinkler systems is assessed very favorably and can make a significant difference to the overall risk quality rating and potentially terms applied.

Selecting a sprinkler design approach:

A range of sprinkler codes and standards may be referenced depending on the country, state, regulatory environment, or insurer. In response to concerns regarding the challenges of fires in modern vehicles, several sprinkler codes have recently increased the required sprinkler water design basis, pending further research, with potential for further changes in the future.

When determining your parking garage sprinkler design strategy, engage with your broker and insurer to help ensure an acceptable solution is agreed for all stakeholders.

Sprinkler Code

Parking Garage Design Basis

Comments

LPC Rules for Automatic Sprinkler Installations 2015 Incorporating BS EN 12845.

High Hazard Process 3

12.5mm/min over 260 sq. m

The LPC Rules include Technical Bulletins designed to ensure the highest reasonably practicable level of property protection, life safety and reliance to fire. LPC Rules are typically referenced by UK property insurers, rather than BS EN 12845 alone.

The sprinkler design basis for car parks was recently increased from Ordinary Hazard 2 (5mm/min over 144 sq. m) to High Hazard Process 3 (12.5 mm/min over 260 sq. m).

NFPA 13: Standard for the installation of sprinkler systems (2025)

Ordinary Hazard Group 2

8.1 mm/min over 140 sq. m

(wet)

Commonly referenced and used by property insurers internationally.

The design basis was increased in the 2022 edition from Ordinary Hazard Group 1 to Ordinary Hazard Group 2, increasing the design density from 6.1 to 8.1 mm/min.

FM Data Sheet 3-26: Fire Protection for Non-Storage Occupancies

Interim Revision October 2021

HC-3

e.g. 12 mm/min over 230 sq. m (ceiling height up to 9m, wet)

The design density varies based on wet/dry system and ceiling height.

Data sheets are published by FM Global (an insurer) and used internationally.

The design basis was increased in January 2021 from HC-2 to HC-3, for example increasing the required density by 50% for ceilings up to 9m.

BS EN 12845: Fixed firefighting systems – Automatic sprinkler systems – Design, installation, and maintenance (2015)

Ordinary Hazard 2

5mm over 144 sq. m

(wet)

EN 12845 is primarily used in parts of Europe.

Property insurers will likely reference other (more current) sprinkler codes such as LPC Rules, NFPA or FM data sheets.

An updated version of EN 12845 currently in development.

Date: 14 October 2024. Please reference the respective sprinkler codes for full detail.

The regulatory requirements to install sprinklers in parking garage areas will vary based on country, state, or other features. For example, where NFPA 88A Standard for Parking Structures 2023 Edition has been adopted, this requires sprinklers to be installed. Irrespective of building regulatory requirements, the needs of other stakeholders need to be considered including the use of the building (resilience) and insurance providers.

Types of vehicles: electric vehicles (EV) and internal combustible engines (ICE)

Electric vehicles have become a more common topic of discussion when considering car parking arrangements. Such vehicles have introduced new considerations such as fire extinguishment challenges from battery fires and the introduction of new electrical equipment to facilitate car charging. It is important to note, however, that fire sprinkler requirements generally do not differentiate between EV and ICE. Both types of vehicles can present significant challenge in the event of a fire in an enclosed parking garage.

When considering fire safety risks for EV, several documents are now available including RC59 – recommendations for fire safety when charging electric vehicles (opens a new window) and T0194 covered car parks – fire safety guidance for electric vehicles (opens a new window) (interim guidance).

In conclusion, enclosed parking garage areas for both ICE and EV can present a significant fire challenge which has also been reflected in recent changes to sprinkler guidance. For further information, please visit the Lockton Risk Control (opens a new window) page, or contact your broker or insurer.

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