Fire investigation in the UK is a structured, evidence-led process used to determine the origin, development, and cause of a fire once it has been extinguished. Investigations may be carried out by Fire and Rescue Services, the police, insurers, or specialist investigators, depending on the circumstances of the incident.
Understanding how fire investigations are conducted — including key concepts such as the seat of fire — is important for duty holders, insurers, and professionals involved in fire safety, compliance, and post-incident review.
This page explains how fire investigations work in practice, who carries them out, and how findings are used to support enforcement, prevention, and risk management.
Contents
- 1 What Is a Fire Investigation?
- 2 Who Carries Out Fire Investigations in the UK?
- 3 The Fire Investigation Process
- 4 Understanding the Seat of Fire
- 5 Identifying Ignition Sources and Fire Cause
- 6 Evidence Collection and Evaluation
- 7 Fire Investigation and Fire Safety Law
- 8 How Fire Investigation Supports Fire Risk Management
- 9 How We Support Organisations After a Fire
- 10 Conclusion
- 11 Frequently Asked Questions
What Is a Fire Investigation?
A fire investigation is the systematic examination of a fire scene to establish:
- Where the fire started
- How it developed
- The ignition source
- The first material ignited
- Whether the fire was accidental or deliberate
Investigations are based on recognised scientific methodology, fire behaviour principles, and objective evidence. The purpose is not speculation, but to form defensible conclusions supported by observable facts.
Fire investigations may be undertaken for several reasons, including statutory duties, criminal investigation, insurance purposes, or to prevent recurrence.
Who Carries Out Fire Investigations in the UK?
Fire investigations in the UK are typically carried out by one or more of the following bodies.
Fire and Rescue Services
Fire and Rescue Services investigate fires to determine cause, support enforcement activity, and contribute to national fire statistics. These investigations follow national operational guidance and focus on public safety and prevention.
Fire and Rescue Service investigations are carried out in line with national operational guidance, ensuring a consistent, evidence-based approach to determining fire cause and supporting enforcement and prevention activity.
Police
Where a fire is suspected to be deliberate, the police lead the investigation. Fire investigators may work alongside the police to provide specialist fire behaviour expertise.
Insurers and Specialist Investigators
In commercial or insured premises, insurers may commission specialist fire investigators to establish cause, liability, and loss implications. These investigations are conducted alongside — not instead of — statutory investigations.
Fire investigators involved in this work may be members of professional bodies such as the UK Association of Fire Investigators, which promotes competence, standards, and continuing professional development.
The Fire Investigation Process
Although the exact approach depends on the incident, most fire investigations follow a structured process.
Scene Preservation and Initial Assessment
Once the fire has been extinguished and the scene is safe, investigators assess the extent of damage, fire patterns, and structural condition. Early observations are critical, as evidence can deteriorate quickly.
Witness Accounts
Witness statements may be gathered from occupants, staff, or first responders. These accounts help establish timelines, fire development, and any unusual activity prior to ignition.
Determining the Seat of Fire
The seat of fire is the area where the fire is believed to have originated. Importantly, this is not always the area of greatest damage.
Fire severity is influenced by fire load, ventilation, and building layout. For example, a fire may originate at a low level but cause greater damage in areas with higher combustible content or improved oxygen supply.
Investigators assess burn patterns, smoke damage, material response, and structural effects to identify the most likely origin.
Understanding the Seat of Fire
The term seat of fire is widely used in fire investigation to describe the point of origin. Identifying it requires a detailed understanding of how fire behaves in uncontrolled conditions.
Indicators used may include:
- Directional burn patterns
- Smoke staining and heat effects
- Structural deformation or collapse
- Material consumption and damage progression
It is important to recognise that no single indicator is conclusive. Findings must be evaluated collectively and objectively.
Identifying Ignition Sources and Fire Cause
Once the seat of fire is established, investigators examine potential ignition sources that may be present in that area, such as:
- Electrical equipment or wiring
- Gas appliances or pipework
- Heating equipment
- Portable electrical devices
Investigators also consider whether the fire developed naturally or whether external intervention may have been involved. Where evidence suggests deliberate ignition, the investigation may escalate to a criminal inquiry.
Evidence Collection and Evaluation
Fire investigation relies on careful evidence handling. Where required, samples may be collected for laboratory analysis to support conclusions about materials, ignition sources, or accelerants.
In cases involving suspected criminal activity, evidence handling follows stricter protocols to preserve integrity and admissibility.
Reporting and Review
Fire investigation findings are documented in a clear, structured report setting out:
- Scope and limitations
- Observations and evidence
- Analysis and conclusions
- Supporting rationale
Reports must be accurate, objective, and capable of standing up to professional or legal scrutiny. In some cases, investigators may be required to explain or defend their conclusions at inquests, inquiries, or court proceedings.
Fire and Rescue Services also record incident data to support national fire statistics and enforcement activity. These records are separate from insurance or civil investigation reports.
Fire Investigation and Fire Safety Law
While fire investigation focuses on understanding what happened, its findings often inform wider fire safety management.
Under the Regulatory Reform (Fire Safety) Order 2005, duty holders must take reasonable steps to prevent fire and protect relevant persons. Investigation findings may highlight failures in fire precautions, maintenance, or management that require corrective action.
Post-incident reviews commonly feed into updated fire risk assessments and remedial planning.
How Fire Investigation Supports Fire Risk Management
Fire investigations do not replace fire risk assessments, but they provide valuable insight into:
- How fire spread occurred
- Whether fire precautions performed as intended
- Weaknesses in building design, maintenance, or management
These lessons help organisations reduce the likelihood and severity of future incidents.
Findings from a fire investigation may also highlight failures in compartmentation, fire-resisting construction, or the performance of external wall and cladding systems. This is particularly relevant where fire spread has occurred beyond the area of origin, or where external wall systems have contributed to rapid vertical or lateral fire development. Such issues can be further assessed through targeted passive fire protection surveys.
This learning-led approach is central to preventing recurrence and strengthening fire safety arrangements across similar premises and activities.
How We Support Organisations After a Fire
While we are not a statutory investigating authority, we support organisations following fire incidents by providing:
- Fire risk assessment reviews
- Compliance advice aligned with current UK legislation
- Practical guidance on managing identified risks
- Clear documentation to support insurers, regulators, and internal governance
Our role is to help duty holders understand implications, address deficiencies, and improve fire safety arrangements going forward.
If you require professional fire safety advice following an incident, our team can provide clear, proportionate support.
Conclusion
Fire investigation plays a crucial role in understanding how and why fires occur, supporting enforcement activity, insurance decisions, and improvements in fire safety management. By identifying the seat of fire, ignition sources, and contributing factors, investigations provide evidence-based insight into fire behaviour and building performance.
While statutory authorities lead formal fire investigations, the findings often highlight wider issues relating to fire risk assessment, maintenance, and compliance. For duty holders, understanding these outcomes is essential to preventing recurrence and meeting legal responsibilities under UK fire safety legislation.
At Fire Risk Assessment Network, we support organisations by helping them interpret fire investigation findings, review fire risk arrangements, and implement proportionate, practical fire safety measures. Clear understanding, accurate information, and effective risk management remain central to protecting people, property, and compliance.
If you require professional fire safety advice following a fire incident, our team can provide clear, structured support to help you move forward confidently.
Frequently Asked Questions
What Is the Seat of Fire?
The seat of fire is the area where a fire is believed to have originated. It is identified by analysing fire damage patterns, material response, and fire behaviour indicators, and is not always the area of greatest damage.
Who Investigates Fires in the UK?
Fire investigations may be carried out by Fire and Rescue Services, the police (where deliberate fire is suspected), insurers, or specialist fire investigators, depending on the circumstances.
Is a Fire Investigation a Legal Requirement?
Fire investigations are carried out as part of statutory duties, criminal investigations, or insurance processes. While not every fire requires a full investigation, significant incidents are routinely examined.
What Is the Difference Between Fire Investigation and Fire Risk Assessment?
Fire investigation looks at what caused a specific fire after it has occurred. A fire risk assessment is a proactive process required by law to identify and manage fire risks before an incident happens.
Can Fire Investigation Findings Affect Enforcement Action?
Yes. Findings may be used to support enforcement, insurance decisions, or legal proceedings where failures in fire safety management are identified.
