EPISODE: 014 - APPROVED DOCUMENT B - FIRE SAFETY - PART 1 OF 4

BYTNAR - TALKS

EPISODE 014 - APPROVED DOCUMENT B - FIRE SAFETY - PART 1 OF 1

This episode is for people who want to know more about Approved Document Part B – Fire Safety.

You should like this episode if you ask yourself questions like:

• What are the key fire safety requirements outlined in Approved Document B for residential dwellings?

• How does Regulation 38 impact the responsibilities of building managers regarding fire safety information? What is the importance of early fire detection and alarm systems in fire safety planning?

• How should escape routes in residential buildings be designed according to Approved Document B?

• What methods are recommended to prevent the spread of fire between different areas of a building?

• How does structural integrity contribute to fire safety in residential construction?

• What is a holistic approach to fire safety, and how should it be implemented during building design?

• How can fire safety engineering be used as an alternative to standard prescriptive measures in fire safety?

• What resources and standards, like British Standard 7974, are used for designing optimal fire safety measures?

LET'S TALK ABOUT YOUR PROJECT

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This is Bytnar Talks: The Engineer Talks on Construction, Episode 14.

Hi, I'm Piotr Bytnar. Each day, I help my clients plan and design building projects through Bytnar Limited, a consulting Chartered Structural Engineers practice.

My biggest passion—and the cornerstone on which I've built my business—is finding clever solutions for construction projects.

I am a Chartered Structural Engineer and a budding software developer, so you can rest assured that I will strive to talk about the best practices and the use of new technologies in the industry.

And if you're embarking on a construction project or are involved in planning, designing, and building the world around us, you'll find this podcast useful.

Approved Document B – Fire Safety, Part One 🔥

🎵 [Intro Music]

Hi there, and welcome back to Bytnar Talks, your favorite podcast on all matters of architecture, engineering, and construction.

It is Thursday, the 2nd of May 2024, and I'm here back with you for the 14th episode and further information on approved documents.

Another busy week is gone, and the we (maybe you meant "weight"?) of the weekend makes us all look forward to tomorrow.

Last week, in Episode 13, I finished talking about the Building Regulations Requirement A – Structure, committing the entire episode to the aspect of disproportionate collapse.

I've told you about the different classes of buildings—from Class 1 to Class 3 and ‘Sary’ (S.A.R.Y – Structures At Risk – Yet to be classified?)—what these are, and how to approach them from the perspective of robustness to avoid disproportionate collapse.

Now, we move into the interesting world of fire safety in and around buildings, and this will take the next several episodes.

The Approved Document B divides its attention between dwellings and buildings other than dwellings. I think, given the scope of the documents, there will be several episodes on the dwelling side of things, and similarly on non-dwellings.

I will enhance the commentary on the approved document with some insight from BS 9999, which is the standard code of practice that deals with fire safety in the design, management, and use of buildings.

So, let us have a closer look at the subject.

Without further ado, let's dive into the fire safety requirements as treated in the Approved Document B. 🎵

Right after the consideration of structures comes the consideration of fire. Sure thing—there is no need to consider fire if the building won't stand—but fire can also be one of the major contributors to building failure and collapse, not to mention loss of life.

Fire considerations spread far and wide over other parts of the legislation too and should be treated as part of the holistic building design process and consideration.

In this episode, I will discuss the considerations that the Secretary of State draws our attention to.I will go section by section, giving you simple reasons behind the text, and where appropriate, my commentary.

This episode will cover Section 0 and Section 1. However, the Approved Document B (Volume 1) consists of 18 sections and 7 appendices, discharging requirements with glorious titles of B1 to B5, with additional mention of Regulation 6 paragraph 3, Regulation 7 paragraph 2, and obviously Regulation 38.

Are you all set? Good.

Let’s unpack it a little bit, shall we?

This episode talks about Volume 1 of Approved Document B – Fire Safety, dealing with dwellings only.

The document follows the requirements B1 to B5 of the Building Regulations, which simply require:

• Provision of sufficient alarm and means of escape (B1)

• Inhibition of fire spread internally, externally, between buildings, or in hidden spaces and cavities (B2, B3, B4)

• Assuring the building will remain structurally sound for the required time (B3)

• Provision of firefighting facilities (B5)

It also mentions Regulation 38, which requires the provision of fire safety information to the responsible person managing the relevant building.

In almost all but single-family dwellings and single units in blocks of flats, you have a relevant building.

It needs to be understood that all these aspects, although dealt with in isolation, form an interconnected approach to fire safety in dwellings and need to be approached iteratively and holistically.

Further clarification is contained within appendices, where specific information can be found in one place.

The document references the Fire Protection Association as a go-to institution for upgrading fire safety to levels beyond that of the minimum requirement described in the Approved Document.

The document also mentions that it is not intended to exclude people for any reason from the use of the building except in extreme circumstances. It should also be considered that the guidance can be met in other ways, but only such alternatives will be fine if they do not increase the risk level compared to the solution otherwise accepted by the document. The guidance is general for typical use scenarios, and some additional considerations may be needed—for example, provisions for fire safety in sheltered housing, where occupants may not be capable of using the building with the same fluency as the general public.

Fire safety engineering is considered a good approach—a good alternative to the approved document. Today, the approved guidance of the Approved Document, British Standard 7974: Application of Fire Safety Engineering Principles to the Design of Buildings, is one such guidance document that could prove useful in finding the alternative approach to Approved Document ways of doing things.

The approved document's guidance follows the identification of the level of hazards of a particular building by assigning a Purpose Group relevant to the use of that building. As we all know, compartments and buildings can vary in their use and be mixed, so the general consideration in such circumstances—if the use is unlike the main designation—is to use the approach of the higher group. But some concessions can be made if the part is sufficiently big to be treated on its own.

When it comes to separated compartments, each compartment should be treated on its own merits.

So, what is the classification here?

As we talk about dwellings, I will consider this group only, which falls under Volume 1 of Approved Document B. And they basically fall under the consideration of the Purpose Group – Volume 1: Dwellings, as I say.

So, flats, dwelling houses with floors at a level not higher than 4.5 metres above the ground, two floors up to the height of a maximum of 18 metres in the sky, and houses with floors below ground level.

Under this provision, we are generally talking about housing provision and building uses that can be ancillary to it—like a small garage or home office, perhaps a surgery even. If provisions fall outside of this purpose group, some further requirements—those dealt with in Volume 2—may need to be considered, like in the case of mixed-use buildings.

Okay, so let’s talk about these simple housing conditions for buildings in Volume 1, shall we?

What we’re talking about here is decreasing risk as we go down the group designation.

So the highest one would be flats, which fall under Group 1A.Then we go to higher risk houses, which are Group 1B,and finally, typical houses, which fall under the consideration of Group 1C.

Now let’s consider Requirement B1 – Means of Warning and Escape.

The regulations say:

“The building shall be designed and constructed so that there are appropriate provisions for the early warning of fire and appropriate means of escape in case of fire from the building to a place of safety outside the building, capable of being safely and effectively used at all material times.”

And what does the Secretary of State have to say about this?

For the Secretary of State, it means:

• There is sufficient early warning system in place;

• That all people can escape unhindered;

• There is sufficient provision of escape routes, in terms of location, number, and capacity;

• Escape routes are sufficiently protected from the effects of fire and smoke;

• Escape routes are sufficiently lit and signed;

• Escape routes are either not overly impacted by smoke, or smoke is being removed;

• Fire spread is restricted;

• And for flats, sufficient provision is made for a staged evacuation strategy.

🎵 [Music]

Section One – Fire Detection and Alarm Systems

As a minimum, all dwellings should have Grade D2, Category LD3 alarm systems in place.

What this means is:

• Grade D2, according to BS 5839, means the alarm system is mains-connected with battery backup, and

• Category LD3 means detectors are located in escape routes only.

We always recommend an LD2 approach as a minimum—placing additional sensors in higher-risk rooms like the kitchen or living room. But preferably, houses should be equipped using the LD1 approach, with additional sensors in places where fire is likely to originate, like the garage or under-stair meter cupboards.

Note that if the dwelling is large, which means it has:

• 200 square metres of floor area per storey,

• and is at least two storeys,

  
  

  (not considering the basement)...

The minimum alarm should be Grade A, Category LD2.

Now, Grade A means separate detectors, alarms, and a central control unit and indicators with backup power supply, according to BS EN 54.

When you do an extension, a fire alarm system should be installed when you:

• Add a habitable room over or below a ground storey,

• And if it is provided at the ground storey also when there is no final exit from that room

In any way, when you propose an extension to the existing house, smoke alarms should be provided in circulation areas.

Similar expectations for the provision of a minimum detection and alarm system are prescribed to flats, treated as separate compartments, so that they do not need a communal alarm system.

The document also recognizes student accommodation as a unique entity, but such units—if they hold no more than six people—are generally considered as compartmentalised flats. Similar due consideration to flats should be given.

However, if the building has a total evacuation strategy in place, this building will fall under the consideration of Volume Two for the provision of fire detection and alarms.

In special situations where people can and need to be aided by assistance, such as in sheltered housing, the alarm system should be connected to a monitoring point informing the responsible person about the fire and its location.

Here, in sheltered housing flats that fall under Volume One consideration, the document goes to state the obvious: that all systems need to be coordinated well, installed properly, and maintained to assure their appropriate operation.

🎵 [Music]

So here you have it—Approved Document B, introduction, and Sections 0 and 1 under the belt.

I delved a little bit into the essential aspects of fire safety regulations for residential buildings, particularly focusing on dwellings. I trust you have gained some appreciation of the key requirements outlined in Volume One of the Approved Documents B – Fire Safety, which spans provisions from early fire detection to effective means of escape.

The document emphasizes the interconnected nature of fire safety measures and highlights the need for a holistic approach—one that addresses:

• Early detection and alarms

• Escape routes

• Fire spread inhibition

• Structural integrity

• And firefighting provisions

It is crucial to appreciate Regulation 38, which necessitates the provision of fire safety information to responsible parties managing relevant buildings.

We can have the best system in place, but if we do not know how to use it and maintain it, I doubt it will be of much use.

The fire safety approach briefs inclusivity—fire safety measures should not exclude individuals unless under extreme circumstances.

I think the most important part of approaching fire safety considerations is to do it iteratively. When doing fire safety planning, these measures should be approached holistically and adapted as needed to suit specific context and evolving needs.

Mind you that fire safety engineering is a viable alternative approach, with the use of British Standard 7974 and other published documents as valuable resources for designing buildings with optimal fire safety measures.

In any case, we approach the consideration by assigning buildings to different risk categories, delineating specific requirements for each category, and specifying appropriate solutions for a given building.

In the next episode…

I will cover:

• Section 2 and 3 – Means of Escape from Dwelling Houses and Flats,

• And Section 4 – Addressing Requirement B2: Internal Fire Spread – Linings.

🎵 [Music]

I hope you enjoyed this episode and that the consideration of fire safety in buildings begins to make more sense to you.

If you have any questions, reach out to me on LinkedIn or send me an email. I’m more than happy to help you out.

At Bytnar Ltd, we deal with planning, designing, and managing your projects, and we are always glad to facilitate a free initial consultation to steer you in the right direction.

Visit www.bytnar.co.uk/advice and let us steer you in the right direction.

At Bytnar, we help our clients design and execute their dream homes or investments.If your building is falling apart, we can also help investigate the reasons behind it, and provide you with an appropriate strategy, design, and specifications for repair.

Thank you again for listening. Please voice your opinions—I'm waiting for you on LinkedIn, and I want to hear from you.

Toodloo!

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Piotr Bytnar BEng (Hons) MSc CEng MIStructE

Chartered Structural Engineer who deals with the Architecture of buildings. His Master's Studies led him to an in-depth understanding of risk and contract arrangements in construction as well as specialist knowledge in soil mechanics.

He and his team help homeowners and property developers to design and deliver construction projects reducing waste in time and the cost. He believes that the construction project is an iterative process that can be well managed and it is best managed if all the aspects of the project definition and management are dealt with in-house or coordinated by one organisation. His team works to all stages of RIBA and ISTRUCTE stages of work and enables contractors to deliver projects on-site providing risk evaluations, methodologies for execution of works and temporary works designs.

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