Fire Rated Systems
Fire Rated Windows
About Fire Rated Windows
Fire rated windows are windows tested to hold back fire and smoke for a classified period, and BDF Architectural supplies and installs fire rated aluminium windows for commercial, healthcare and high-rise residential buildings across London and the UK. The rating each window needs, most commonly EI30 or EW30 (30 minutes), is set by the fire strategy and confirmed at technical review against the system's test evidence.
Fire rated windows are typically needed where a window sits in a compartment wall, looks onto a protected stair or escape route, or where the rules on fire spread between buildings limit unprotected glazing. Fixed fire rated glazing is tested to EN 1364-1 and openable fire rated windows to EN 1634-1, and both are classified to BS EN 13501-2 as E (integrity), EW (integrity with limited radiation) or EI (integrity and insulation), followed by the time in minutes. The frame, glass, intumescent seals and fixings are tested together; the seals expand under heat to close the gaps around the frame and glass. An openable window only gives its rating when it is shut, so the fire strategy sets whether each one is fixed, kept locked or closes automatically in a fire.
A fire rated window is an individual window set into a wall. A fixed run of internal glazing that forms the wall itself, often with doors in it, is a fire rated glazed screen or partition, which we cover on our Fire Rated Screens & Partitions page.
The glass decides which classification a window can reach. Non-insulating fire-resistant glass, such as special fire-resistant toughened, ceramic or wired glass, is used for E and some EW ratings; ordinary toughened safety glass is not fire rated on its own. Insulating fire glass, built up with interlayers that foam in a fire, is used for EI ratings. For external windows a fire-resistant pane can be combined with a second pane in an insulating glass unit for thermal performance, and the glass must be a product rated for external use.
Fire performance sits alongside everything else expected of a premium aluminium window: concealed fittings, slim sightlines, thermal insulation, weathertightness, sound reduction, burglary and vandalism protection options, barrier-free options and any RAL powder-coat colour. Periods longer than 30 minutes depend on a system having been tested to that duration at the sizes and configuration needed, which we check before quoting rather than promising a rating in general.
To price fire rated windows, send elevations, the window schedule with sizes, the classification each window needs or the fire strategy, and programme dates.
Last reviewed 2 November 2026
Key features
- Classification to suit the fire strategy, commonly EI30 or EW30
- Intumescent seals expand under heat to prevent fire and smoke passage
- Concealed fittings for a clean, architectural appearance
- Thermal insulation and weathertightness alongside fire performance
- Burglary and vandalism protection options
- Sound reduction
- Barrier-free accessibility options available
- Available in any RAL powder-coat colour
- Fire performance confirmed for each project from the system's test evidence
- Fixed glazing tested to EN 1364-1; openable windows to EN 1634-1
Specifications
Frequently asked questions
Common questions about Fire Rated Windows.
What is a fire rated window?
A window tested as a complete assembly of frame, glass, seals and fixings to hold back fire for a classified time. It is tested to EN 1364 and classified to BS EN 13501-2 as E, EW or EI followed by the time in minutes, for example EI30. BDF Architectural supplies and installs fire rated aluminium windows across London and the UK.
Are fire rated windows available in 30, 45, 60 and 90 minute ratings?
Fire resistance is classified in set periods such as 30, 60 or 90 minutes, and the fire strategy sets the period each window needs. EI30 and EW30 are the most common for windows; 45-minute window ratings are more usual in North American codes than in UK fire strategies. A longer period is only available where a system has been tested to that duration at the size and configuration you need, so we confirm what can be achieved for your openings at technical review rather than quoting a rating in general.
What is the difference between EW30 and EI30 windows?
Both keep their integrity, holding back flames and hot gases, for 30 minutes. EW30 also limits the heat radiated through the glass. EI30 adds insulation, keeping the unexposed face cool enough for people to pass close by. EI is typically asked for where people need to pass close to the glazing while escaping, but the fire strategy decides which applies.
Where are fire rated windows needed?
Wherever the fire strategy calls for fire-resisting glazing. Typical cases are windows in a compartment wall, windows looking onto a protected stair or escape route, and external windows where the rules on fire spread between buildings limit unprotected glazing. In England the guidance is Approved Document B.
What glass is used in fire rated windows?
Non-insulating fire-resistant glass, such as special fire-resistant toughened, ceramic or wired glass, is used for E and some EW ratings. Insulating fire glass, with interlayers that foam in a fire, is used for EI ratings. Ordinary toughened safety glass is not fire rated on its own. External windows can combine a fire-resistant pane with a second pane in an insulating glass unit, using glass rated for external use, and the glass is only rated in the frame it was tested with.
Can a fire rated window open?
Yes, but it only gives its fire rating when it is shut. Openable fire rated windows are tested to EN 1634-1, while fixed fire rated glazing is tested to EN 1364-1. The fire strategy sets whether each window is fixed, kept locked or closes automatically in a fire.
Do you supply fire rated windows to contractors and the trade?
Yes. BDF Architectural is a commercial glazing contractor based in West Drayton, west London, supplying and installing fire rated aluminium windows for main contractors, developers and architects across London and the UK. The fire rating comes from the window system's test evidence, not from the fabricator or installer, so each window is priced from the schedule and checked against that evidence, including how it is fixed and sealed into the surrounding wall.
Do fire rated windows still perform as normal windows?
Yes. The aluminium systems we supply combine fire resistance with thermal insulation, weathertightness, sound reduction, concealed fittings and burglary and vandalism protection options, in any RAL powder-coat colour. Each performance is confirmed for the actual configuration at technical review.
How do I get a price for fire rated windows?
Send elevations, the window schedule with sizes, the classification each window needs or the fire strategy, and programme dates through the enquiry form on our contact page, by email to info@bdfa.uk or on 0800 999 5575.
Pricing Fire Rated Windows?
Send drawings, schedules and programme dates for a tender price, or call 0800 999 5575.
