Steel window lifespan UK: How long do they last and when should you replace?

Will my steel windows’ lifespan be greater than other materials?

While hardwood or aluminium can last for decades, galvanised steel is widely considered the “lifetime” choice, outlasting both these materials by a considerable margin.

Of course, the durability of steel windows will depend on the production process. Here Crittall sets the modern standard. By fusing time-honoured craftsmanship with advanced technological innovation, we remain the global leader in steel window and steel doors manufacturing.

What’s the expected lifespan for Crittall steel windows in the UK?

The combination of Crittall’s professional hot-dip galvanising and the specialised Duralife® powder coating system creates a finish designed for extreme longevity. With proper maintenance, Crittall’s steel window lifespan UK can easily exceeding 60 years, with a fine example of Crittall’s windows lasting over 100 years here.

Are aluminium ‘Crittall – style’ windows any good?

Many companies sell aluminium windows marketed as “Crittall-style”. While aluminium is more affordable than steel, it does not have the “generational” 60 – 100 year durability of genuine, galvanised steel windows.

Also, as steel is stronger than aluminium, genuine Crittall windows are made with exceptionally slim frames, allowing the maximum natural light in your living space.

Are Crittall steel windows hard to maintain?

Crittall needs surprisingly little effort to keep it looking its best. With no repainting required, our steel frames with Duralife® powder coating just need washing with a soft cloth and mild detergent (avoid abrasive cleaners) every six to 12 months. Additionally, choosing triple glazing options can provide unobstructed views while further enhancing insulation and energy efficiency.

Other than surface cleaning, the hinges and handles are the only parts of the window that should experience wearing. The best way to keep these lubricated is with a light engineering oil such as 3-in-One oil once a year to keep everything moving freely.

How will I know when to replace my Crittall Windows?

Knowing when to replace your Crittall windows depends largely on whether they are “Original” (pre-1950s) or “Modern” (post-1980s). Because steel is so robust, Crittall windows rarely “fail” structurally; instead, they usually reach a point where their thermal performance, susceptibility to condensation, or mechanical operation no longer meets strict energy efficiency standards or your needs. Investing in new steel windows can be a great choice to greatly enhance the comfort and warmth of your interior spaces, ensuring they are the right fit for your lifestyle.

Here are the key indicators that it’s time to consider replacing older Crittall metal windows, especially for improved thermal efficiency:

1. The “Rust Jacking” Stage

“Rust jacking” occurs when moisture gets deep into the steel, causing it to expand and exert pressure on the surrounding materials. If a very old window frame has signs of rust and has physically warped, it cannot safely be straightened and will need replacing, as it may no longer be the correct fit anymore.

2. Excessive Paint Build-Up

On older, non-galvanised windows, decades of repainting can create a thick “crust” that prevents the windows from closing flush against the frame, which can lead to increased energy consumption. While specialists can sometimes strip the frames to restore them and ensure structural integrity, replacement is often more cost-effective.

3. Single Glazing Limitations

Many Crittall windows from the early 20th century are single glazed. Even if the steel is in perfect condition, the glass itself may be the reason to replace to prevent heat loss, especially if you prioritise energy efficiency. Upgrading to a modern Crittall T60 or Homelight Plus system provides the same look as earlier windows but with high-performance thermal breaks giving an excellent insulating barrier against harsh weather. The Corporate W20 TE® range is our latest addition and also achieves fantastic thermal performance equivalent to that of a thermally broken steel section.

4. Hardware failure

If a building has windows from the 1920s-40s, finding matching hardware can be difficult. If multiple windows have mechanical failures, a full replacement ensures modern multi-point locking security.

Interested in finding out more?

For homeowners who value authentic craftsmanship and long-term performance, Crittall steel windows offer an ideal solution. Each installation blends practical performance with refined style, creating windows that continue to contribute to the character and comfort of a property for decades. Factors that can affect the lifespan of a steel window include the quality of the installation, regular maintenance and care, local climate conditions, exposure to moisture and corrosion, and the type of coatings or finishes applied to protect the steel. With proper attention to these elements, steel window longevity can be maximised in any home. 

For more information about Crittall’s steel windows, please contact us here.