Lawrence Webster Forrest (LWF), Fire Engineering and Fire Risk Management Consultants
Lawrence Webster Forrest (LWF), Fire Engineering and Fire Risk Management Consultants


Client login
Forgotten password
Follow us on Twitter Follow us on Facebook Subscribe to our blog

Lawrence Webster Forrest
Legion House
Lower Road

Tel: +44 (0)20 8668 8663 Fax: +44 (0)20 8668 8583

Fire Engineering Design and Risk Assessment - E.F.R. and Firefighting - Part 12

Posted by LWF: 01/11/2018 12:59

In LWFs Fire Engineering blog series for architects and others in the building design business, we have been looking at compartmentation. In part 11, the advantages and disadvantages of using equivalent fire resistance were discussed. In part 12, we look at equivalent fire resistance (E.F.R.) from the perspective of BS 9999.

BS 9999:2017 - Fire safety in the design, management and use of buildings. Code of practice looks at equivalent fire resistance for use in conjunction with a concept named ‘occupancy characteristic’ (oc). The combination allows recommendations for compartmentation in different types of building and occupancy. It also takes into account the risk profile. BS 9999 relays this information in a table format which allows the reader to discern a fire-resistance period calculated using equivalent fire resistance and which considers key parameters such as height of the building.

The calculation method used in BS 9999 differs from the methods used in CIB and Eurocode.


Although most readers will associate the term ‘firefighting with the Fire Service, it can also be used to refer to the efforts to subdue a fire taken by building occupiers or any other individual or organisation. Although the official fire service in different parts of the world will be known by different names, we shall refer to them all as ‘fire service’ throughout to avoid confusion.

Just as there are standards which relate to fire safety and fire engineering solutions, there are codes containing prescriptive standards for the fire service too. The methods involved can be grouped into three headings – strategy, tactics and operation.

Strategy relates to the planning of fire service objectives, such as saving the lives of persons affected by fire, mitigating damage to property and to the environment from fire and from the firefighting activities undertaken. 

Tactics refers to those methods employed at the site of a fire to achieve the objectives listed in strategy, above.

Operations are how the equipment and techniques can be used to fulfil the tactical plan.

Of course, for the maximum effectiveness of the methods, it is important that the fire service are able to attend the fire as soon as possible, however, due to geographical location, demand for the service and facilities available, attendance times can vary significantly. Because of this, it is important that fire safety measures are in place at the destination to enable an assessment of potential maximum size of a fire for when the fire service arrive. In addition, any resources inside and outside of the building, such as water mains, should be available and functioning.

In part 13 of this series, LWF will continue to look at firefighting from the point of view of the occupier of a building. In the meantime, if you have any questions about this blog, or wish to discuss your own project with one of our fire engineers, please contact us.

Lawrence Webster Forrest has been working with their clients for over 25 years to produce innovative and exciting building projects. If you would like further information on how LWF and fire strategies could assist you, please contact Peter Gyere on 020 8668 8663.

While care has been taken to ensure that information contained in LWF's publications is true and correct at the time of publication, changes in circumstances after the time of publication may impact on the accuracy of this information.

Leave a reply





[ Change the image ]


Subscribe to our fire safety blogs

Email Format
* indicates required


  • Fire Engineering Design and Risk Assessment - Firefighting - Part 14

    In LWFs fire safety engineering blog series for Architects and others in the building design business, we have begun to look at firefighting. In part 13, we began to look at how firefighting can be undertaken by the occupiers of a building if a fire starts. The use of portable fire extinguishers was discussed along with relevant training was discussed. In part 14, the provision of hose reels and the standards involved will be covered.


  • Fire Safety for Healthcare Premises - External Fire Spread - Part 48

    In LWF’s blog series for healthcare professionals, the aim is to give information on best practice of fire safety in hospitals and other healthcare premises. In part 47 of this series, LWF took a look at the use of sprinkler protection in healthcare venues and in part 48, we begin to discuss the potential for external fire spread and what precautions should be taken to avoid it.It should be borne in mind that we...


  • Facilities Management & Fire Safety - Fire Safety Engineering & the Prescriptive Approach - Part 5

    In LWFs blog series for those who work in facilities management or who have an interest in or responsibility for fire safety, we have been looking at the term ‘Fire Safety Engineering’ and what it involves. In part 4 of the series, we began to look at the differences between fire prevention and safety based on prescriptive codes and fire safety engineering. In part 5, we will continue from that point by looking at the...


  • Fire Engineering Design and Risk Assessment - Firefighting - Part 13

    In LWF’s fire engineering blog series for architects and others in the building design business, we began discussing firefighting. In part 12, an overview of the term and its meaning before looking at the method of firefighting, namely the strategy, tactics and operations of the Fire Service in the UK and equivalent organisations in other parts of the world. In part 13, we look at firefighting by occupiers of a building.Firefighting undertaken by occupiers...


  • Fire Safety for Healthcare Premises - Sprinklers - Part 47

    In LWF’s blog series for healthcare professionals, the aim is to give information on best practice of fire safety in hospitals and other healthcare premises. In part 46 of this series, we looked at the tank arrangement for sprinkler systems and how each pump should be arranged to draw water from either tank, so that any one tank or pump can be isolated. In part 47, we continue from that point on the subject of...


Case Studies

The Wohl Neuroscience Institute - Fire Safety, Strategy & Engineering
Key Facts: Client: King’s Clinical Neuroscience Institute Project Manager: MACE Ltd Designers: Devereux Architects/Allies and Morrison Approximate Size: 7,400m2 Description of the Project:...

Read more..

General Bulletins

Fire - The External Risk
When we consider fire safety, our focus is normally from within, what can we do to prevent the occurrence of fire and how we can limit its damage.  Whilst this is the correct stance to take, we m...

Read more..

Technical Bulletins

Evacuation Modelling - Factor in Human Behaviour
Evacuation of buildings can be analyzed in different ways. Approved Document B (ADB) which provides guidance on meeting the requirements of the England and Wales Building Regulations with regard to fi...

Read more..

Site map | Web development London