Should You Replace Your Double-Glazed Units – or the Whole Window?

When your windows start misting up or losing efficiency, it’s easy to assume the whole lot needs replacing. But sometimes, that’s not the smartest (or most cost-effective) move.

In fact, if your existing window frames are still in good condition, you might only need to replace the double-glazed units themselves - and that can save you a small fortune.

What’s the difference?

The sealed unit is the glass part - two panes with a gap in between, filled with insulating argon gas and sealed around the edges. The frame is what holds it in place.

If the frame is solid, secure, and not warped or damaged, changing just the glass unit could give you over 80% of the thermal performance of brand-new windows - at roughly 40% of the cost.

Why this makes sense

Modern double-glazed units have come a long way. Today’s glass can:

• Reflect heat back into your home with special low-emissivity coatings
• Let in free solar warmth
• Use high-performance argon gas for better insulation

That means you’ll notice a warmer, quieter home and lower bills - all without the disruption or cost of a full replacement.

Minimal mess, maximum benefit

Companies like Crystal Clear who deliver a great service covering much of the North of England and growing rapidly, specialise in this kind of work. They’ll:

• Check whether your current sealed units meet modern standards
• Replace only the glass if your frames pass inspection
• Fit new gaskets for a perfect seal
• Clean and refresh your existing uPVC frames
• Even upgrade your handles and locks if you want

No scaffolding. No plaster repairs. No risk of disturbing asbestos. Just quick, tidy, value-for-money results.

The cost and environmental win

Replacing just the double-glazed units usually costs less than half of full replacement - and because you’re reusing the frames, there’s far less waste. Companies like Crystal Clear also recycle the old glass, so it’s a great choice for anyone thinking about sustainability as well as savings.

When it’s not the right choice

If your frames are cracked, warped, or letting in draughts, a full replacement might still be the better long-term option. But a professional installer will tell you honestly which route makes sense for your home – some like Crystal Clear offer both services.

In short…

If your frames are still sound, replacing just the glass could give you the warmth, efficiency, and clarity of new windows for a fraction of the cost - without the mess or upheaval.

It’s definitely worth considering before you commit to full replacements.

HowMuch4 Windows helps you understand your options before you spend a penny - so you know what to ask, what to expect, and what’s fair value for your home.

Know what it costs. Know what to ask.