A steel-framed door can preserve light, sightlines and a carefully considered plan – but where fire separation is required, its appearance is only one part of the specification. Choosing required fire door rating starts with the role the opening plays in the building’s fire strategy. The answer is not automatically ‘the highest rating available’. It is the rating that has been designed, approved and evidenced for that particular wall, route and use.
For a London renovation, a new-build home or a commercial fit-out, getting this decision right early protects the programme as well as the finished design. A fire-rated door cannot be treated as a standard glazed partition with a stronger frame added later. Its glass, frame, seals, hinges, lockcase, closer and installation method form a tested system.
Start with the building’s fire strategy
The required performance should come from the project’s fire strategy, Building Regulations requirements and, where applicable, the advice of Building Control, an approved inspector or a fire engineer. These documents establish how the building is compartmented, how occupants escape and how long each element needs to resist fire.
The location of the door is decisive. An opening within a protected escape route may need a different rating from a door dividing two areas of a workplace. A door to a flat entrance, a stair enclosure, a plant room or a corridor has a specific function in limiting smoke and fire spread. In contrast, a decorative internal steel door between an open-plan kitchen and living space may not require a fire rating at all, unless the wider design or approval route says otherwise.
This is why plans alone rarely provide a complete answer. Ask what the wall is separating, whether it forms part of an escape route, what rating the wall itself achieves, and whether the door must control smoke as well as fire. The opening should then be specified to meet that requirement without disrupting the architectural intent.
Choosing the required fire door rating: E or EI?
The letters before the number matter as much as the minutes after it. They describe the performance criteria demonstrated by the tested door set.
E means integrity. An E30 door is designed to maintain its integrity for 30 minutes, helping prevent flames and hot gases passing through from one side to the other. It can be the appropriate choice where the project requirement is for fire integrity rather than insulation.
EI means integrity and insulation. An EI30 or EI60 door must resist the passage of fire and limit the temperature rise on the unexposed face for 30 or 60 minutes respectively. This can be particularly relevant where people may pass close to the protected side, where combustible materials are nearby, or where the fire strategy calls for a higher level of performance.
Neither classification is a shorthand for ‘better-looking’ or ‘more premium’. E and EI serve different performance requirements, and the correct choice depends on the approved specification. EI systems often have different construction demands, which can affect glass make-up, frame depth, weight, maximum leaf sizes and the available level of visual openness.
What the numbers mean
The number indicates the test duration in minutes. E30 and EI30 provide 30-minute performance under their respective criteria. E60 and EI60 provide 60-minute performance. A 60-minute rating is not simply a sensible upgrade for every project. It may add cost, weight and detailing constraints without being necessary, while still failing to solve the problem if the surrounding wall or installation is not suitable.
Specify the rating required by the project, not a rating selected from a price list.
Treat the door as a complete fire-rated assembly
A compliant fire door is a door set, not just a leaf. This is especially significant with slim steel glazing, where the visual result relies on precise junctions between steel, glass and ironmongery.
The tested or assessed configuration will define the permitted frame profile, glass type and thickness, panel layout, maximum dimensions, leaf arrangement and hardware. It may also define the wall construction into which the frame can be fixed. Changing any of these elements can take the finished door outside the scope of its evidence.
For example, swapping a tested lever handle, lock or hinge for an alternative chosen purely for its finish may compromise the certification position. Removing a door closer because it feels visually intrusive can leave a fire door open when it must be closed to perform. Enlarging a glazed panel or introducing a bespoke arched head may be possible, but only where it is supported by the relevant system evidence.
This does not mean fire-rated steel doors must look heavy or compromise a refined interior. It means the design needs to be developed within a proven system from the outset. The best results retain narrow sightlines and generous glazed areas while respecting the limits of the fire-rated construction.
Check smoke control and everyday use
Fire resistance and smoke control are related but separate considerations. Smoke can make an escape route untenable before fire breaches a door. Where smoke leakage performance is required, the specification may call for seals tested for ambient-temperature smoke, often shown as Sa, and/or medium-temperature smoke, often shown as S200.
Do not assume an intumescent strip alone provides the required smoke performance. Intumescent materials react in heat; smoke seals address leakage before activation. The requirement, if any, should be stated in the door schedule or fire strategy and supported by the door set’s tested configuration.
Operational details also matter. A fire door generally needs to close fully onto its seals and latch correctly. In a busy office, hospitality space or family home, that may influence whether a hold-open device, access control, panic hardware, automatic closing arrangement or a particular closer type is appropriate. Each choice must be compatible with the certified system.
Match the rating to the surrounding construction
A 60-minute door fitted into a partition that only provides 30-minute resistance does not create a 60-minute opening. Equally, a high-performing wall can be undermined by an incorrectly installed frame or unprotected service penetrations around it.
Before ordering, confirm the wall type and thickness, the structural opening, head condition and fixing substrate. Masonry, concrete, metal stud and glazed screen constructions may each require a different approved fixing and perimeter sealing detail. On refurbishment projects, hidden conditions are common: an apparently solid wall may include voids, timber infill or services that need resolving before installation.
The threshold deserves the same attention. A raised threshold, drop seal or clear floor gap can affect smoke control, accessibility, acoustic expectations and the visual continuity of flooring. There is rarely a one-detail-fits-all answer. The correct threshold is the one that meets the tested evidence and suits how the space will be used.
Avoid three costly specification shortcuts
The first shortcut is specifying ‘fire-rated steel door’ without stating the actual classification. That leaves too much room for assumptions. Record whether the requirement is E30, EI30, E60 or another defined performance, together with any smoke, acoustic, security or accessibility requirements.
The second is selecting the rating before the fire strategy has been checked. A designer may favour a large glazed double door, but the route may require self-closing single leaves, a particular smoke seal or a different level of protection. Resolve that tension on paper, not after fabrication.
The third is separating design, manufacture and installation decisions. Fire performance depends on how all three align. Retain the product documentation, approved drawings, installation records and certification information for the completed door set. This is valuable at handover, during future alterations and if the property is later sold or reconfigured.
Give the supplier the information that changes the answer
A meaningful quotation or technical review needs more than opening width and height. Provide the latest plans, the proposed wall build-up, the fire-door schedule or fire strategy extract, the preferred handing and configuration, and any requirement for sidelights, overpanels, access control or special ironmongery. Interior visuals are useful too, particularly where slim profiles, arched glazing or a specific grid arrangement are central to the scheme.
Artsteel can then assess whether a certified E30, EI30 or E60 steel system can achieve the intended proportion and detailing, rather than forcing a design-led brief into a generic fire-door format.
A well-specified fire door should feel considered rather than conspicuous. Establish the required performance first, keep every component within the tested system, and the finished opening can deliver both the separation the building needs and the clarity of design the space deserves.