Double Glazing - Cost Effective
Triple Glazing - Premium Performance
By The Windows and Doors Team
Your Local Glazing & Home Improvement Experts
Reading Time: 9 minutes
Quick Summary
his guide explains the real price difference between double and triple glazing for UK homeowners and professionals.
We’ll answer: How much does triple glazing cost?, Is triple glazing better than double glazing?, and Should you choose double or triple glazed windows?
Expect cost tables, regulatory notes, and practical advice to compare options fairly.
The first question is always: “How much is triple glazing?”
Unfortunately, the answer depends on many factors such as the type of window, frame material, and installation complexity all play a role.
To provide clarity, here are average costs for uPVC windows in England
Typical prices in England
So how much do triple glazed windows cost across a whole house?
For a semi-detached property with an average number of windows (8–10), totals are usually £6,000–£7,500 for double glazing and £7,500–£10,000 for triple glazing.
Larger detached homes with 15–20+ openings often exceed £15,000–£20,000 for uPVC, while aluminium or timber systems can push project totals to £25,000 or more.
Key takeaway: Expect the average cost of triple glazing to be 25–35% higher per unit compared with double glazing.
Why the premium? Each triple glazed unit has an additional pane, another spacer, more gas fill, a deeper frame profile, and heavier hardware.
More material plus extra labour means a higher triple glazed windows price.
Many articles use the vague phrase “glazing vs double glazing,” but the real question is always double glazing vs triple. Both are sealed units, but they differ in construction:
Double glazed windows: Two panes with a warm-edge spacer, argon gas cavity, and a sealed perimeter.
Triple glazing windows: Three panes with two separate cavities, each gas-filled.
That difference between double and triple glazing matters.
An extra cavity cuts conduction and convection, improving heat retention and reducing heat loss.
This means warmer interior glass surfaces, improved comfort, and less risk of condensation.
When weighing double or triple glazing, remember: double glazing already meets regulations and is cost-effective, while triple glazing provides comfort and future-proofing.
Approved Document L (2022) requires a maximum whole-window U-value (Uv) of 1.4 W/m²K.
Typical performance levels are:
Double glazing (uPVC window systems): 1.3–1.6 Uv.
Triple glazing: 1.0–1.2 Uv, with high-end designs reaching 0.8–0.9.
However, not all triple glazing is automatically better. Some lower-spec triple units only achieve ~1.2–1.3 Uv, overlapping with A-rated double glazing.
Always check certified whole-window values before making a choice.
Precision Engineered Thermal Excellence
When comparing double or triple glazed windows, check more than just cost:
Types of glass: Low-E for energy efficiency, laminated for security and sound, solar-control for overheating risk.
Spacer & gas fill: Warm-edge spacers and argon are standard. Krypton boosts insulation in some premium triple glazed units.
Installation details: Correct sealing, ventilation, drainage, and packers ensure the unit remains thermally efficient and durable.
Is triple glazing better than double glazing for bills? Thermally yes, but financially the difference is modest.
Single → Double glazing: Major energy saving, cutting heating bills by hundreds per year.
Double → Triple glazing: For a semi, annual savings are usually £20–£55. In detached properties with a larger glazed area, this can rise to £60–£80, while in smaller flats savings may fall below £20.
So the price difference between double and triple glazing isn’t recovered quickly through fuel bills. Still, many homeowners choose triple because:
The inner pane stays warmer, reducing cold draughts.
Condensation around edges is reduced.
Comfort levels rise across the room.
In other words, triple glazing helps reduce heat loss, but its immediate value is in comfort more than savings.
To show clients the difference between double or triple glazing fairly:
1. Gather Uv values for both units.
2. Multiply each Uv by the total glazed area and number of windows.
3. Apply local degree-day data and energy bills.
4. Present the energy saving alongside the upfront premium.
This provides a clear, site-specific picture of the difference between double glazing and triple glazing.
Acoustics: In triple glazing vs double glazing, the sound difference isn’t always dramatic. Standard triple glazing may offer little benefit over double glazing. For low-frequency traffic noise, an asymmetric build or laminated double glazing may outperform standard triple.
Security: Triple glazing adds resistance by including an extra pane, but laminated glass in either type gives the biggest security boost.
Durability: Heavy triple glazed sashes require upgraded hinges and handles. Long-term life depends on sealed-unit quality and correct installation.
– You need compliance at the lowest glazed windows cost.
– Budget and quick payback are essential.
– The home is in a mild or quiet area.
It’s a new build or deep retrofit targeting energy efficiency.
-The property is in a noisy or cold location.
-Comfort and thermally efficient design are priorities.
-You want to future-proof against stricter standards.
Always compare the same type of window across suppliers and insist on documented Uv values.
For a semi with 9 windows:
– Double glazed windows: Average £850 each → £7,650 total.
-Triple glazed windows: Average £1,000 each → £9,000 total.
Annual saving: £30–£40 on heating bills.
At that rate, the payback period is long, but the comfort and acoustic benefits may justify the extra cost.
Premium Glazing Comparison Guide
Cost-effective solution for most applications
Premium performance for demanding applications
The price difference between double and triple glazing comes from the extra glass, gas, and hardware.
Triple glazing offers lower U-values, warmer panes, and more comfort, though energy bills savings are modest.
For cost-conscious retrofits, double glazed windows are excellent and compliant.
For cold or noisy homes, or future-proofing, triple glazing windows are often worth the investment.
About £700–£1,100 for a uPVC casement.
A semi with 8–10 windows is usually £7,500–£10,000.
Detached homes with more number of windows often exceed £15,000–£20,000, and aluminium/timber systems can top £25,000.
Yes, for warmth and comfort, but not always for soundproofing.
Triple has an additional pane and cavity, lowering U-values and improving comfort but at a higher cost.
Yes. uPVC is cheapest, timber and aluminium cost more but offer other benefits.
Window Cost Estimates
U-values (Thermal Performance)