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Triple Glazing: Is the 15-20% Extra Cost Worth the Investment?
Triple Glazing: Is the 15-20% Extra Cost Worth the Investment?
Are triple glazed windows really worth the extra money? It is the #1 question we get asked by homeowners. With energy bills high and building regulations tightening, the promise of a warmer home is tempting.
But does the maths stack up? Below, we break down exact triple glazed windows prices in the UK, and we have built two interactive tools to help you calculate the cost and get a personalised recommendation instantly.
- 🔥 Performance: Triple glazing offers a U-value of approx 0.8 W/m²K (40% better than standard double glazing).
- 💷 Cost: Expect to pay exactly 20% more upfront than standard double glazing.
- ❄️ Comfort: It eliminates “cold spots” near windows, allowing you to lower your thermostat.
- 🔊 Noise Warning: Standard triple glazing is NOT better for noise. For soundproofing, choose acoustic laminated glass instead.
Table of Contents
1. How Much is Triple Glazing? (Estimated UK Prices)
When searching for triple glazed windows prices UK, it is important to remember that every installation is bespoke. However, to give you a clear idea, here are the exact cost comparisons for standard uPVC casement windows based on typical sizes.
| Window Size (Width x Height) | Double Glazing Price | Triple Glazing Price (+20%) |
|---|---|---|
| Small Casement (600mm x 1050mm) | £490 | £588 |
| Standard Casement (1200mm x 1200mm) | £600 | £720 |
| Large Casement (1800mm x 1200mm) | £750 | £900 |
*Note: Prices are estimates for standard uPVC. Specialised frames like woodgrain effects or aluminium will increase the overall cost. For an exact quote in Andover or across Hampshire, contact the KJM Group team.
2. Interactive Cost Estimator
As demonstrated above, triple glazed windows cost exactly 20% more than high-quality double glazing. Use the slider below to see how that impacts your overall renovation budget.
*Estimates only based on market averages.
3. Tool: Is it Right for YOU?
There is no “one size fits all.” Tell us about your home, and our logic engine will give you an honest recommendation on whether the extra triple glazed windows prices are justified for your property.
4. The Hard Data: Glass vs. Whole Window
When comparing quotes, it is vital to compare apples with apples. Manufacturers often quote the Centre-Pane U-value (U_g) because it looks better, but the Whole Window U-value (U_w)—which includes the frame—is what actually matters for your energy bills.
The Verdict: Even when accounting for the frame, KJM Triple Glazing is approx. 40% more efficient at stopping heat loss than standard A-rated double glazing.
5. The “Cold Spot” Phenomenon
Why you feel cold at 21°C
Even in a warm room, if you sit near a cold surface (like a standard window), your body radiates heat towards it. This is called Radiant Heat Loss.
Triple glazed windows keep the inner glass temperature much higher (approx 18°C vs 16°C for double). This eliminates the “cold spot,” meaning you can often turn your thermostat down by 1°C without losing comfort.
6. The Noise Myth
⚠️ Warning: Resonance
Many people buy triple glazing for soundproofing, but standard units (4mm-4mm-4mm) can actually amplify traffic drone due to resonance.
The Solution: If noise is your priority, ask for Acoustic Laminated Glass (asymmetric double glazing). It is often cheaper and more effective for noise reduction.
7. Frequently Asked Questions
Yes, significantly. A triple glazed unit contains 50% more glass than a double glazed one. This requires heavy-duty hinges and reinforced frames to prevent sagging over time. KJM only uses hardware rated for this extra weight.
In purely financial terms (energy savings vs upfront cost), the payback period is often 20+ years. However, this doesn’t account for the increased property value, superior home comfort, and future-proofing against stricter EPC regulations.
Actually, yes—and it’s a good sign! Because triple glazing keeps the heat in so well, the outer pane of glass stays cold. On damp mornings, dew can form on the outside (just like on your car). This proves the window is working perfectly to keep the heat inside your home.
📚 Explore Our Glass Knowledge Hub
This article is part of our comprehensive series on high-performance windows.
⭐ Real Reviews, Real Peace of Mind
Our reputation is built on over 700 independent reviews.
- Which? Trusted Traders: 4.9/5 (100% of customers recommend us)
- Google: 4.9/5 (from 250+ reviews)
- Checkatrade: 9.87/10 (from 360+ reviews)
“As a Commercial Construction Project Manager I cannot recommend highly enough the service and window installation that KJM carried out on my home… their communication and service was exemplary.” – KJM Customer Review
We are also a long-standing member of the Glass and Glazing Federation (GGF) and are Trading Standards Approved, so you are fully protected.
Mark Pearce is a highly experienced specialist in the double glazing industry, having built his knowledge from the ground up through hands-on experience in installation, manufacturing, sales, and business management. Beyond his role at KJM, Mark is a keen blogger, writer, and traveller, often sharing insights on the latest innovations in the home improvement industry.
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