A comprehensive guide to window fire ratings

• 13 February 2025
• News

Window fire rating is a crucial consideration for architects, builders and property owners. As building regulations continue to evolve and safety standards become more stringent, understanding the different fire-rated glazing systems available on the market is incredibly valuable. This guide explores everything you need to know about the fire-rated windows manufactured by the team of specialists at Crittall Windows. But first, let’s explore the fundamentals of fire rating in windows.

The fundamentals of fire rating in windows

What is window fire rating?

Fire rating refers to the amount of time a window can withstand exposure to fire conditions while maintaining its structural integrity. The rating is determined through a series of rigorous testing procedures that measure how effectively the window prevents the spread of fire, passage of smoke and transmission of heat between spaces.

Understanding fire rating classifications

Fire resistance levels

Fire-rated windows are classified according to their performance in standardised tests, with ratings typically expressed in minutes – typically, 30, 60 or 120. These ratings indicate how long the window can maintain its integrity under fire conditions. For example, an FD30 rating means the window can withstand fire for a minimum of 30 minutes.

Performance criteria

Fire rated windows must meet three performance criteria during testing. They must:

• Demonstrate their integrity by preventing the passage of smoke and flames between spaces.
• Provide adequate insulation by restricting heat transfer to protect occupants and the property.
• Maintain structural stability even when exposed to high temperatures.

Fire regulations and compliance

Fire safety regulations in new build homes and commercial properties require specific minimum fire ratings based on several key factors. These requirements vary depending on building usage and occupancy levels, distance from means of escape, overall building height and size, and proximity to other structures. Each of these elements must be carefully considered when specifying fire rated windows.

Considerations for different settings

Different environments demand varying levels of fire protection to ensure occupant safety and to reduce the spread of flames. Commercial spaces, educational facilities and healthcare establishments require higher ratings due to increased occupancy and complex evacuation requirements so there is a clear and safe means of escape.

Crittall Windows’ approach to fire safety

Innervision® Fire Rated screens demonstrate how modern fire safety can complement contemporary design. These systems offer FD30 fire rating and achieve impressive insulation properties, while maintaining the signature slim profiles that Crittall Windows’ products are renowned for.

Glazing design that doesn’t compromise performance

The Innervision® range proves that fire safety doesn’t mean sacrificing impressive aesthetics. This is because large fire resistant glazing panels are incorporated into the design, allowing spaces to be flooded with natural light while, at the same time, efficiently protecting homes in the event of a fire.

Benefits of fire rated windows

Enhanced safety features

Modern fire rated windows effectively contain internal fires within designated compartments, preventing fire hazards from spreading between areas. The windows are designed to protect against fire for extended periods, significantly reducing the effects of fire to any occupants.

Long-term value

The benefits of investing in fire rated windows are priceless. Installing products like the Crittall Windows Innervision® range provides complete peace of mind that the appropriate fire safety measures are in place.

From a property owner, architect or builder point of view, this also means that the products installed within commercial or residential spaces remain compliant with current building regulations.

Choosing the right fire rated solution

Fire rated windows are a crucial investment in any renovation or new build project, offering essential protection to properties in the event of a fire. Crittall Windows’ commitment to combining safety with style is evident in the Innervision® Fire Rated range, providing architects, builders and property owners with solutions that don’t compromise on design or safety.

Get in touch today to discuss your project with a member of the Crittall Windows’ team.