F&RM Journal FPA Main Site
ACCESSIBILITY

The development of Sprinkler Rules emerged alongside the growth of leading insurance companies. Their original purpose was to protect high-value property, extensive storage arrangements, and industrial manufacturing processes. Over time, the Rules significantly enhanced economic resilience by limiting the consequences and scale of fire losses.

LPC Rules for Automatic Sprinkler Installations 2015 Incorporating BS EN 12845

Ongoing revisions to the Rules have been essential to reflect continual changes in construction methods, materials, storage processes, building size, and system complexity. Developments in construction practices and subsequent building alterations also drive the need to ensure sprinkler systems are suitably serviced and maintained relative to the prevailing risk. As fires are inherently unpredictable, sprinkler installations may remain dormant for extended periods yet must operate reliably when required; an exceptional engineering and design challenge.

Historically, sprinkler systems date back more than 130 years. The first formal set of rules was produced in 1885 by John Wormald of the Mutual Fire Insurance Corporation Ltd in Manchester and formally published in 1887.

From these foundations, revised and expanded standards were issued by the Fire Offices’ Committee (FOC) from 1888 onwards. Numerous editions followed, incorporating insights gained from fire loss experience, system testing, and the advancement of sprinkler components.

The final FOC Rules were issued as the 29th edition in 1968 and remained in force until being replaced in 1990 by British Standard BS 5306 Part 2. However, this British Standard primarily addressed life safety objectives and did not accommodate the property protection principles central to the former insurance-led FOC Rules.

To address this shortfall, RISCAuthority (then InFires) introduced LPC Technical Bulletins (TBs), specifically reflecting insurer requirements for property protection. Where insurers are involved, these TBs supersede British Standard provisions by enhancing system resilience and incorporating additional protective measures.

In 2003, BS EN 12845 was adopted in the UK as the principal sprinkler standard for life safety. As before, property protection was excluded, resulting in further LPC Technical Bulletins to support risk mitigation for insurers.

Since then, the LPC Rules for Automatic Sprinkler Installations 2015 incorporating BS EN 12845:2015 + A1:2019 have become the primary UK sprinkler standard, uniquely recognised by insurers for addressing both life safety and property protection.

Continuous amendments, updates, and new Technical Bulletins have since been published to reflect changes in construction methods, materials, storage configurations, and building use. Coupled with innovation in system design and component technology, this evolution necessitates that Technical Bulletins remain responsive to an ever-changing risk environment.

Ongoing revisions to the Rules have been essential to reflect continual changes in construction methods, materials, storage processes, building size, and system complexity.

Recent updates to Technical Bulletins

A number of minor updates have recently been introduced across several LPC Technical Bulletins, reflecting emerging industry concerns, updated research, and alignment with current standards. The affected bulletins are:

  • LPC Technical Bulletin TB206: Passive fire protection of sprinklered buildings
  • LPC Technical Bulletin TB214: Sprinkler protection of flammable liquid stores
  • LPC Technical Bulletin TB220: Full hydraulic calculations
  • LPC Technical Bulletin TB234: Protection of High Hazard Storage (HHS) configurations

 

LPC Technical Bulletin TB206: Passive fire protection of sprinklered buildings

TB206 has been subject to a minor update in response to concerns raised by industry specialists regarding requirements for lift shaft safety and the distinction between Low Voltage (LV) and High Voltage (HV) compartments, including transformer installations. The bulletin continues to allow a number of Permitted and Necessary exceptions where sprinkler protection may be omitted, provided that suitable, insurer-approved alternative mitigation measures are implemented.

As part of the recent update, lift enclosures are now permitted to remain unsprinklered where adequate passive fire protection of the enclosure is provided. In addition, oil-filled transformers have been added as a permitted exception to sprinkler protection, again subject to the implementation of appropriate mitigating measures.

Further necessary exceptions have been introduced for areas housing HV electrical distribution equipment, such as switchgear and dry-type (air-cooled) transformers, where these rooms serve no other function. Research has demonstrated that sprinkler discharge onto this type of equipment may introduce additional hazards. In such cases, the use of alternative fire suppression systems should be considered, following a comprehensive risk assessment and agreement with the building’s insurer.

 

LPC Technical Bulletin TB214: Sprinkler protection of flammable liquid stores

Following requests from insurers, TB214 has undergone an extensive review to address the increasing diversity of flammable and combustible liquids currently stored across UK facilities. The review confirmed a significant range of container types, materials, and capacities, presenting considerable challenges for consistent risk assessment and loss mitigation.

Fire testing undertaken in both Europe and America addressed only a limited subset of the possible variables and resulted in highly specific design requirements linked directly to the test parameters. It was therefore concluded that a further update to UK sprinkler provisions could not be adequately supported without an impractical scale of additional fire testing to reflect the wide range of liquids, containers, and storage configurations encountered in practice.

As a result, the existing TB214 has been withdrawn and replaced with guidance directing stakeholders to alternative European sprinkler standards and codes of practice that are supported by robust test data. When applying such standards, caution is advised, as the liquids, containers, or storage arrangements considered in the original fire tests may differ materially from those being protected, potentially affecting fire performance outcomes.

 

LPC Technical Bulletin TB220: Full hydraulic calculations

Recent changes to TB220 are relatively modest in scope but highly important in technical terms. A typographical error was identified within the bulletin’s presentation of the Hazen-Williams formula, which underpins hydraulic calculation methodology for sprinkler systems.

Although the error was subtle and unlikely to have resulted in widespread design issues, given the prevalence of calculation software and established engineering practice, it was essential to correct it to maintain alignment with BS EN 12845 and avoid any ambiguity.

 

LPC Technical Bulletin TB234: Protection of High Hazard Storage (HHS) configurations

TB234 provides guidance on sprinkler protection solutions for the diverse range of warehouse storage configurations found throughout the UK. The systems detailed within this Bulletin have been subject to extensive fire testing over many years and are proven to provide effective fire control for deep storage involving a wide variety of stored commodities.

Previously, general storage on moveable shelving systems exceeding 1m in width, commonly referred to as ST6 storage, was addressed only through the use of roof-level and in-shelving sprinklers. Following a review incorporating the relevant provisions of BS EN 12845, a roof-only sprinkler arrangement was added, supported by hydraulic calculation requirements. This approach is now formally included within the latest update to TB234.

This update underlines the complexity of modern storage risks. TB234 continues to evolve, ensuring that sprinkler protection remains effective as storage heights increase and commodity classifications and configurations become more challenging.

Technical Bulletins – current work in progress

A number of LPC Technical Bulletins are currently under review or revision to reflect evolving standards, emerging research, and changes in system design and component technology. The bulletins presently being reviewed include:

  • LPC Technical Bulletin TB208: Supplementary requirements for sprinkler installations operating in dry mode
  • LPC Technical Bulletin TB203: Care and maintenance of automatic sprinkler systems
  • LPC Technical Bulletin TB229: LPC Rules for automatic sprinkler installations – variations to BS EN 12845:2015
  • LPC Technical Bulletin TB227: Pipework
  • LPC Technical Bulletin TB220: Full hydraulic calculations
  • LPC Technical Bulletin TB234: Protection of High Hazard Storage (HHS) configurations


LPC Technical Bulletin TB208: Supplementary requirements for sprinkler installations operating in dry mode

A comprehensive review of TB208 has been undertaken to reflect the availability of new LPCB-approved products introduced to the market.

The revised bulletin now includes three different pre-action valve sets, all of which are also referenced within the proposed European standard prEN 12845-1, currently under consultation to replace BS EN 12845:2015.

In addition to the introduction of new valve set technologies, the update provides clearer guidance on detection system arrangements and strengthens direct links to the ongoing inspection, testing, and maintenance requirements set out in TB203. To ensure completeness and consistency, the requirements previously contained within TB219 have also been fully incorporated, alongside all existing provisions.


LPC Technical Bulletin TB203: Care and maintenance of automatic sprinkler systems

TB203 is subject to continual review to ensure that maintenance requirements remain aligned with new product developments and revisions to related Technical Bulletins, while avoiding unnecessary increases in operational cost.

The current update reflects the introduction of new pre-action system requirements and incorporates revised guidance relating to the two-year and ten-year inspection and maintenance regimes for sprinkler water storage tanks. These updates have been developed in collaboration with the British Automatic Fire Sprinkler Association (BAFSA) working group, drawing on specialist industry expertise.


LPC Technical Bulletin TB229: Variations to BS EN 12845:2015

Revisions to TB229 are primarily focused on clause TB229.3.23 and include the addition of examples and figures, illustrating supplementary sprinkler protection beneath grouped obstructions. Further guidance is provided through the introduction of a new Figure, which explains how to calculate supplementary protection requirements where multiple services exceed 1000mm in width.

Another new figure clarifies the relationship between obstructions and sprinkler spray patterns, while detailed guidance on sprinkler head positioning relative to both rectangular and circular obstructions, including the required location of the sprinkler deflector are included. Additional requirements have also been introduced for obstructions located above High Hazard Storage configurations and for grouped services installed directly above sprinkler-protected racking.


LPC Technical Bulletin TB227: Pipework

Updates to TB227 include a revision to Table T1, following the withdrawal and replacement of several pipework and fittings specifications. Hydraulic calculation data for steel pipework, together with Table T2, will be migrated into LPC Technical Bulletin TB220 as part of a future update.

Significant revisions have also been made to the use of flexible pipework serving sprinklers within ceiling spaces, with specific requirements defined for both pre-calculated and full hydraulic calculation systems. Figure F1 has been updated to provide clearer installation guidance and now includes references to relevant product certification. Previous references to the Fire Protection Association (FPA) product endorsement for proprietary pipework, fittings, and CPVC pipe systems have been removed, with Figures T2, F3, and Table 3 replaced by revised guidance text. Use of CPVC pipework now refers directly to TB202, which provides dedicated guidance for this material and associated fittings.


LPC Technical Bulletin TB220: Full hydraulic calculations

In response to the revisions made within TB227, TB220 is being updated to incorporate all relevant hydraulic information. This includes alternative Hazen-Williams formulae and revised tables confirming hydraulic data and ‘K’ factors for different pipe types.


LPC Technical Bulletin TB234: Protection of High Hazard Storage (HHS) configurations

Following updates to TB229 and supporting research confirming that supplementary sprinklers do not require inclusion within hydraulic calculations, TB234 will be aligned accordingly, removing this requirement.

Further research and recent fire testing relating to rack storage has identified that ignition location plays a critical role in fire development. When ignition occurs at the midpoint of the transverse flue, rather than at the intersection of the transverse and longitudinal flues used in previous standards testing, fire spread may track both toward the longitudinal flue and toward the rack face. Based on this new understanding, a review of existing sprinkler layouts is underway, with face sprinkler protection to be introduced for specific storage configurations.

The LPC Sprinkler Rules

These forthcoming revisions will ensure that LPC guidance remains consistent with the latest European standards, supporting both life safety objectives and insurer requirements for resilient property protection.

Future LPC Technical Bulletin updates

Following the publication of two new British and European Standards — BS EN 12845-2:2024, Fixed firefighting systems. Automatic sprinkler systems. Design and installation of ESFR and CMSA sprinkler systems, and BS EN 17451:2024, Fixed firefighting systems. Automatic sprinkler systems. Design, assembly, installation and commissioning of pump sets, a number of LPC Technical Bulletins will require revision to ensure continued alignment with current best practice and regulatory expectations.

Implementation of BS EN 12845-2:2024 will necessitate updates to the following Technical Bulletins:

  • LPC Technical Bulletin TB209: ESFR sprinkler protection
  • LPC Technical Bulletin TB225: ESFR sprinkler protection within storage racking
  • LPC Technical Bulletin TB235: Control Mode Specific Application (CMSA) sprinklers

The introduction of BS EN 17451:2024 will require corresponding updates to LPC Technical Bulletin TB210: Automatic sprinkler pump installation.

These forthcoming revisions will ensure that LPC guidance remains consistent with the latest European standards, supporting both life safety objectives and insurer requirements for resilient property protection.

Working groups

Through technical working groups, RISCAuthority supports the UK insurance industry by proactively identifying emerging risks and current challenges affecting property insurance, and by investing in solutions that mitigate loss and disruption. Its work focuses on maintaining and enhancing industry guidance that underpins insurer confidence, promotes effective property protection, and ensures that such measures remain both technically robust and financially attractive to property owners.

RISCAuthority also acts as a central point of collaboration, bringing together insurers, industry bodies, and other stakeholders with a shared interest in business and property protection. Where appropriate, it seeks alignment with government policy to support consistent and practical risk management outcomes.

As part of its role within the FPA, RISCAuthority contributes to national and international standards committees. This voluntary work is extensive, reflecting the continual need to respond to technical developments, research findings, testing outcomes, and emerging technologies.

The LPC Rules for Automatic Sprinkler Installations remain a benchmark for world-class protection, balancing life safety requirements with insurer expectations for property protection.

Developed in close collaboration with UK insurers, the BAFSA, and the Loss Prevention Certification Board (LPCB), the LPC Rules continue to provide comprehensive and trusted guidance for a wide range of commercial and industrial buildings across the UK.

Dr Dale Kinnersley

Article written by
Dr Dale Kinnersley
Principal Consultant Fire Protection Association

MORE FEATURED ARTICLES

Looking at PEEPs
Evacuations and inclusion
Social responsibilities