FD30 vs E30 vs EI30 Glass Fire Doors Explained

FD30 vs E30 vs EI30 at a Glance

Classification	Integrity	Insulation	Duration
FD30	Yes	Not indicated by classification	30 minutes
E30	Yes	No	30 minutes
EI30	Yes	Yes	30 minutes

FD30

Integrity Yes

Insulation Not indicated by classification

Duration 30 minutes

E30

Integrity Yes

Insulation No

Duration 30 minutes

EI30

Integrity Yes

Insulation Yes

Duration 30 minutes

This provides a useful overview. However, the correct classification for a project should always be established from the project’s specific fire requirements and supporting documentation.

What Does FD30 Mean?

FD30 is terminology widely recognised throughout the UK construction industry.

Under the national classification route, FD30 refers to a fire doorset providing 30 minutes of fire resistance in terms of integrity when tested to the relevant BS 476 fire-resistance standard.

Therefore, you may see FD30 specified on architectural drawings, door schedules and fire strategies.

You may also encounter FD30S. The additional S indicates that smoke leakage requirements apply as well.

Importantly, a door described as FD30 should not automatically be assumed to hold an equivalent European classification. The supporting evidence for the particular doorset should always be considered.

What Does E30 Mean?

The E in E30 stands for integrity.

In simple terms, integrity relates to the ability of a construction to resist the passage of fire from the fire-exposed side to the unexposed side during the stated period.

Therefore, an E30 doorset provides 30 minutes of integrity performance under the applicable European test and classification regime.

Approved Document B recognises European classifications under BS EN 13501-2 for fire doorsets tested using the relevant European standards.

For steel and glass fire doors, this distinction is particularly important. The steel frame, fire-resistant glazing, seals, hardware and associated components work together as a complete doorset.

As a result, an E30 classification applies to the performance of the doorset as a system, rather than simply to the steel frame or fire-resistant glass individually.

Is E30 the Same as FD30?

Not exactly.

Both FD30 and E30 can relate to 30 minutes of fire resistance in terms of integrity. As a result, the terms are sometimes used as though they mean precisely the same thing.

However, they belong to different classification routes.

A product with evidence supporting an FD30 classification should not simply be assumed to have an E30 classification. Likewise, you should check the evidence supporting a specification rather than relying solely on the description “30-minute fire door.”

This distinction becomes particularly important when comparing products from different suppliers.

For example, two doors may both be described as providing 30 minutes of fire resistance. Nevertheless, the applicable test standards, classifications, permitted dimensions and configurations may differ.

What Does EI30 Mean?

EI30 provides different performance from an E30 classification.

The classification can be broken down as follows:

E = Integrity
I = Insulation
30 = 30 minutes

Therefore, an EI30 doorset must satisfy both integrity and insulation criteria for the stated period.

Integrity concerns the ability of the doorset to resist fire passage. Insulation, meanwhile, relates to limiting the transfer of heat to the unexposed side.

Consequently, an EI30 glazed steel door may require a different steel profile and specialist fire-resistant glazing from an integrity-only E30 system.

Why Does Insulation Matter?

Glazed fire doors present a particular challenge because heat can transfer through glass.

Specialist fire-resistant glazing systems are available with different levels of fire performance. However, simply installing a pane of fire-resistant glass does not automatically make a doorset EI30.

Instead, the glass needs to form part of a compatible fire-rated construction capable of achieving the required classification.

Therefore, the correct solution will depend on the project’s fire strategy, the position of the door and the required level of performance.

Why Does the Classification Matter With Steel and Glass Doors?

A fire-rated steel and glass door should be considered as a complete doorset, rather than a collection of individually fire-rated components.

Its fire performance can depend on several elements, including:

the steel profile system;
fire-resistant glazing;
glazing beads and associated components;
intumescent materials and seals;
hinges;
locks and latches;
door closers;
door-leaf dimensions;
glazing-bar configuration;
sidelights and toplights;
supporting construction; and
installation.

As a result, changing one part of a proposed design can potentially affect whether the doorset remains within the scope of its supporting fire-performance evidence.

For example, a system may support a particular single-door size. However, that does not necessarily mean an unrestricted double-door arrangement of the same overall dimensions will also be covered.

Similarly, adding sidelights, toplights or different glazing arrangements may affect the specification.

This is why it is important to consider the complete proposed configuration, rather than simply selecting fire-resistant glass and a steel frame independently.

What Does EW30 Mean?

ou may also encounter the classification EW30, particularly when specifying glazed fire doors.

The E refers to integrity, while the W relates to radiation. An EW classification therefore considers the doorset’s ability to maintain integrity while also limiting the level of heat radiation transmitted to the unexposed side.

In simple terms:

E30 = Integrity for 30 minutes
EW30 = Integrity + radiation control for 30 minutes
EI30 = Integrity + insulation for 30 minutes

EW30 is therefore different from both E30 and EI30. Although all three may provide 30 minutes of fire resistance against their respective criteria, they should not be treated as equivalent classifications.

This distinction is particularly relevant for steel and glass fire doors, where the type of fire-resistant glazing and framing system can affect the level of performance achieved.

Therefore, if a project specifies EW30, the proposed doorset should have appropriate supporting evidence for EW30 performance. The required classification should be confirmed against the project’s fire strategy or specification.

Can a Fire-Rated Steel Door Have Large Areas of Glass?

Yes. Fire-rated steel doors can incorporate large areas of glass, provided the complete doorset is designed and supported for the required fire classification.

However, using fire-resistant glass does not automatically mean that any size or configuration can be manufactured. The permitted glazed area depends on the particular steel profile system, fire-resistant glazing, door dimensions and supporting fire-performance evidence.

For example, different systems may have limitations relating to:

maximum door-leaf dimensions;
maximum glass dimensions;
single or double-door configurations;
sidelights and toplights; and
the position or requirement for glazing bars.

This is particularly important with steel and glass fire doors, where architects, designers and homeowners often want slim frames combined with large, uninterrupted areas of glass.

Therefore, the required fire classification should be established first. A suitable system and configuration can then be selected within the scope of its supporting test, classification or assessment evidence.

Large glazed fire doors are possible, but the maximum size and configuration should always be determined by the evidence supporting the complete doorset rather than the glass alone.

What Does the “S” in FD30S Mean?

The “S” in FD30S relates to smoke control.

An FD30 doorset provides 30 minutes of fire resistance in terms of integrity under the relevant national classification route. When the additional S is specified, the doorset must also meet the applicable requirements for restricted smoke leakage at ambient temperatures.

Smoke control is important because smoke can spread through a building before fire reaches a particular area. Therefore, in certain locations, a fire door may need to restrict the passage of smoke as well as maintain its required fire resistance.

Under the European classification route, you may instead encounter the classification Sa, which relates to smoke leakage at ambient temperature. For example, a specification may require E30 Sa rather than simply E30.

However, not every 30-minute fire door automatically requires smoke-control performance. Whether it is required depends on factors such as the location of the doorset, the building design and the project’s fire strategy.

Therefore, if a door schedule specifies FD30S rather than FD30, the “S” should not be overlooked. The proposed complete doorset needs to provide the required fire resistance and appropriate smoke-control performance.

The project’s architect, fire engineer or Building Control professional should confirm the required classification where necessary.

What Should I Ask a Steel Door Company About Fire Ratings?

When choosing a steel door company for a fire-rated project, it is important to compare more than the appearance of the doors and the quoted price.

First, establish exactly what fire classification is being offered. A door described simply as “30-minute fire rated” does not necessarily tell you whether it provides E30 integrity performance, EI30 integrity and insulation performance, or another classification.

You should also ask whether the proposed size and configuration are supported by the relevant fire-performance evidence. This is particularly important for bespoke steel and glass doors, where changes to dimensions or design can affect what is permitted.

For example, consider asking:

What fire classification does the complete doorset achieve?
What test, classification or assessment evidence supports it?
Is my proposed door size and configuration covered?
Are double doors, sidelights or toplights permitted?
What fire-resistant glass is being specified?
Is smoke-control performance required and, if so, is it supported?
Are the proposed hardware and glazing arrangements compatible with the fire-rated system?

Therefore, when comparing different steel door companies, make sure you are comparing like-for-like specifications. Two doors may look almost identical and both be described as “fire rated”, while the actual classification and supporting evidence can be very different.

For a fire-rated project, the key question is not simply “Is this a fire door?” but “What fire performance does this complete doorset provide, and what evidence supports the configuration being proposed?”

Which Fire Door Classification Do I Need?

The correct fire door classification depends on the specific requirements of your project. There is no single fire rating or classification that is suitable for every door or location.

One of the first considerations is the required period of fire resistance. Depending on the project, you may encounter requirements for 30, 60, 90 or even 120 minutes of fire resistance.

For example, specifications may include classifications such as:

FD30 or FD60 – commonly used UK national fire-door terminology;
E30 or E60 – integrity for 30 or 60 minutes;
EW30 or EW60 – integrity with a radiation criterion;
EI30 or EI60 – integrity and insulation for the stated period; or
classifications that include an additional smoke-control requirement.

The required performance depends on factors such as the door’s location, the building’s fire strategy, compartmentation requirements and the type of protection required.

Therefore, you should not choose a fire-rated steel and glass door simply because it is described as a “30-minute” or “60-minute fire door.” The number tells you the duration, but the letters identify the type of fire-resistance performance being provided.

For example, E60 and EI60 both refer to 60-minute classifications, but they do not provide the same performance. E60 relates to integrity, whereas EI60 includes both integrity and insulation criteria.

Similarly, if your architectural drawings or door schedule specify FD30 or FD60, you should not automatically assume that this is interchangeable with an E or EI classification. The project’s actual requirements and the supporting evidence for the proposed doorset need to be considered.

Once the required classification has been established, an appropriate steel and glass fire door system can be selected. Its dimensions, glazing, configuration and hardware should then fall within the scope of the relevant supporting fire-performance evidence.

Fire Door Classifications Are Changing in England

The way fire resistance is specified in England is changing, making classifications such as E30, E60, EI30 and EI60 increasingly important to understand.

Approved Document B has historically allowed two routes for the fire-resistance testing and classification of construction products: the National Classes based on BS 476 and the European classification system based on the BS EN 13501 series.

However, the government is withdrawing the National Classes from Approved Document B in stages.

References to BS 476 for reaction to fire and roofs were removed from the guidance from 2 March 2025. The next significant change for fire doors is scheduled for 2 September 2029, when references to the BS 476 national classification system for fire resistance will be removed from Approved Document B.

From that point, the European BS EN classification system will become the sole route of specification within Approved Document B for fire-resistance classifications, subject to the published transitional arrangements.

This is particularly relevant when specifying fire doors because familiar terminology such as FD30 and FD60 comes from the national classification route. European classifications instead use performance designations such as E, EW and EI, together with the period of fire resistance.

For example, you may increasingly encounter specifications such as:

E30 or E60 – integrity for the stated period;
EW30 or EW60 – integrity together with a radiation criterion; and
EI30 or EI60 – integrity and insulation for the stated period.

Importantly, this does not mean that an FD30 doorset can simply be renamed E30, or that FD60 automatically becomes E60. The classifications come from different test and classification routes, so the appropriate supporting evidence for the doorset remains important.

What About Existing Projects?

The government has included transitional arrangements for the September 2029 change.

The earlier version of Approved Document B can continue to apply where the relevant building notice, initial notice or building control approval application with full plans was made before 2 September 2029, provided the building work meets the government’s requirements for being started and sufficiently progressed within the applicable transition period.

For the 2029 fire-resistance changes, that period is six months.

Therefore, the applicable requirements should always be checked against the timing and circumstances of the individual project.

As the industry moves towards the European classification system, understanding the difference between FD, E, EW and EI classifications will become increasingly important when comparing fire-rated steel and glass doors.

For the latest requirements and transitional provisions, refer to the official government guidance:

Approved Document B – Fire Safety (GOV.UK)

Choosing the Right Fire-Rated Steel and Glass Door

Choosing a fire-rated steel and glass door involves balancing fire performance, architectural design and the practical requirements of the opening. Rather than starting with appearance alone, it is useful to establish the project’s essential requirements first and then identify a system capable of delivering them.

Consider the following questions at an early stage:

What fire classification is required? Confirm both the performance criteria and duration, such as E30, E60, EI30 or EI60.
What is the size of the opening? Larger openings may influence the systems and configurations available.
Is a single or double door required? The permitted dimensions and arrangements can differ.
Are sidelights or toplights required? Fixed glazed sections can form part of some fire-rated configurations, but their inclusion needs to be supported by the relevant system evidence.
How important is profile width? Different fire-rated steel systems have different sightlines. A very slim architectural appearance may require a different system from a project where profile width is less important.
What glass appearance is required? Clear glass is not always the only possibility. Depending on the tested or assessed system, other glazing options may be available.
What hardware is needed? Handles, locks, closers and other hardware should be considered as part of the complete doorset rather than selected independently afterwards.

Fire Performance and Design Need to Be Considered Together

One of the advantages of modern steel and glass fire doors is that fire protection does not necessarily mean sacrificing architectural design. Large glazed areas, slim sightlines and bespoke configurations may be achievable while still providing the required fire performance.

However, there are limits.

A design should not be created first and then assumed to be fire rated simply because fire-resistant glass can be fitted into it. Instead, the proposed door should be developed around a fire-rated system capable of supporting the required configuration.

This is particularly important for bespoke projects involving unusually tall or wide doors, double doors, fixed glazed screens or toplights.

Compare the Complete Specification

When comparing quotations, make sure you are comparing equivalent products.

Two steel and glass doors can appear almost identical in an architectural drawing or photograph while using very different profiles, glazing, hardware and fire-performance classifications.

Therefore, price should be considered alongside the complete technical specification and supporting evidence.

Ultimately, the right fire-rated steel and glass door is one that meets the project’s required fire performance while achieving the desired design within the capabilities of an appropriate tested or assessed system.

Once the required classification, approximate opening dimensions and preferred configuration are known, Doors of Steel can help identify which of our fire-rated systems may be suitable for the proposed design.

→ Explore our Fire-Rated Steel & Glass Door Systems

Frequently Asked Questions

How do I know if I need a 30-minute or 60-minute fire door?

The required fire-resistance period should come from the project’s fire strategy, architectural specification, door schedule or Building Regulations requirements. It depends on factors such as the building type, location of the door and the fire-resisting construction it forms part of.

You should not choose between a 30-minute and 60-minute door based on preference alone. If the requirement is unclear, ask the project’s architect, fire engineer, Building Control professional or other competent person to confirm it before ordering

Can I have reeded, fluted or obscured glass in a fire-rated steel door?

yes, but it depends on the particular fire-rated system and glazing configuration.

Decorative or obscured glass cannot simply replace the specified fire-resistant glass. However, some systems can accommodate an additional decorative glass layer alongside the required fire-resistant glazing, allowing effects such as reeded, fluted or obscured glass while retaining the required fire-rated construction.

The proposed glass build-up must therefore be compatible with the particular doorset and its supporting fire-performance evidence.

Do internal steel and glass fire doors need to be self-closing?

In many applications, yes, a fire door will require a suitable self-closing device, although the requirement depends on where the doorset is installed and the applicable fire-safety requirements.

Where self-closing is required, the closer forms an important part of the doorset because a fire door can only perform its intended function when it is properly closed.

Depending on the fire-rated steel door system, this may be achieved using a visible overhead closer or a concealed/integrated closer, provided the chosen closer is suitable for the particular fire-rated doorset.

My architect has specified FD30 – can I use a steel and glass fire door instead of a timber fire door?

Potentially, yes. A requirement for a fire door does not necessarily mean that the door must be manufactured from timber.

Steel and glass doorsets can provide fire-resistance performance while maintaining a glazed architectural appearance. However, the proposed steel and glass doorset must provide the fire performance required by the project and have appropriate supporting evidence for its size and configuration.

If the specification states FD30, it is also important to establish the precise classification requirement rather than automatically assuming that any 30-minute steel and glass fire door is equivalent. Your architect, fire engineer or other responsible specifier should confirm that the proposed classification is acceptable for the project.

Published by Doors of Steel
Specialists in internal steel and glass doors and fire-rated steel door systems.

Last reviewed: September 2026

FD30 vs E30 vs EI30 Fire Doors: What’s the Difference?

FD30 vs E30 vs EI30 Fire Doors: What’s the Difference?

FD30 vs E30 vs EI30 at a Glance

FD30

E30

EI30

What Does FD30 Mean?

What Does E30 Mean?

Is E30 the Same as FD30?

What Does EI30 Mean?

Why Does Insulation Matter?

Why Does the Classification Matter With Steel and Glass Doors?

What Does EW30 Mean?

Can a Fire-Rated Steel Door Have Large Areas of Glass?

What Does the “S” in FD30S Mean?

What Should I Ask a Steel Door Company About Fire Ratings?

Which Fire Door Classification Do I Need?

Fire Door Classifications Are Changing in England

What About Existing Projects?

Choosing the Right Fire-Rated Steel and Glass Door

Fire Performance and Design Need to Be Considered Together

Compare the Complete Specification

Frequently Asked Questions

How do I know if I need a 30-minute or 60-minute fire door?

Can I have reeded, fluted or obscured glass in a fire-rated steel door?

Do internal steel and glass fire doors need to be self-closing?

My architect has specified FD30 – can I use a steel and glass fire door instead of a timber fire door?

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