How Much Do Double Glazing Units Cost?
Indicative UK prices for double glazing sealed units – budget with confidence before requesting your free personalised quote.
Price by Unit Size
The table below shows indicative supply-only prices for standard 4-16-4 air-filled sealed units. These are our starting prices – your exact quote may vary depending on glass type, gas fill, and quantity.
| Unit Size (W × H) | From Price |
|---|---|
| 500 × 500 mm | From £70 |
| 600 × 900 mm | From £90 |
| 800 × 1200 mm | From £110 |
| 1000 × 1000 mm | From £120 |
| 1200 × 1200 mm | From £150 |
| 1200 × 1800 mm | From £190 |
Note: Prices shown are for standard 4-16-4 air-filled units, supply only. Upgrading to argon gas fill or specialist glass types will adjust the price. We manufacture to any custom size – see our measuring guide for how to measure your units accurately.
Price by Glass Type
The type of glass you choose has a significant impact on the cost of your sealed unit. Below is a guide to the typical price premium for each glass type compared to standard float glass.
| Glass Type | Price Impact |
|---|---|
| Standard float | Baseline |
| Low-E soft-coat | +15–20% |
| Toughened (BS EN 12150) | +25–30% |
| Acoustic laminated | +30–40% |
| Triple glazed | +50–70% |
| Self-cleaning | +20–25% |
| Obscure / patterned | +10–15% |
Most homeowners replacing misted or failed units opt for Low-E soft-coat glass with argon gas fill – this combination offers excellent thermal performance and easily meets Building Regulations Part L requirements. For ground-floor or vulnerable locations, toughened glass is a legal requirement under BS EN 12150 and should be factored into your budget.
Price Impact of Gas Fill
The gas between the panes of your sealed unit affects both thermal performance and cost. Here's what each gas fill option adds to the price of a standard unit.
| Gas Fill | Additional Cost per Unit |
|---|---|
| Air | Baseline (included) |
| Argon | +£10–£20 |
| Krypton | +£30–£60 |
| Xenon | +£80–£160 |
For most UK homes, argon gas is the best value upgrade – it improves insulation by around 34% over air for just a few pounds per unit. Read our full gas fills guide for a detailed comparison of argon, krypton, and xenon.
What Affects the Price?
Several factors combine to determine what you'll pay for your double glazing units. Understanding each one helps you make informed decisions and avoid surprises when you receive your quote.
- Size – Larger units require more glass and more gas fill, so the price scales with the overall area. A 1200 × 1800 mm unit costs roughly 2.5 times more than a 500 × 500 mm unit.
- Glass type – Specialist glass such as toughened, laminated, or triple-glazed panes carries a premium over standard float glass. See the glass type table above for typical percentage uplifts.
- Gas fill – Upgrading from air to argon adds a small cost; krypton and xenon are progressively more expensive. For most homes, argon provides the best balance of performance and value.
- Shape – Standard rectangular units are the most economical to manufacture. Bespoke shapes – arched tops, circular, triangular, or trapezoidal – require custom tooling and attract a premium.
- Quantity – Ordering multiple units at once reduces the per-unit cost. We offer trade discounts and volume pricing for larger orders. See our trade page for details.
- Delivery distance – We offer free delivery on orders over £300. For smaller orders or remote locations, a delivery charge may apply. All units are delivered on a nationwide service across the UK.
Supply Only vs Supply & Install
When budgeting for replacement double glazing units, it's important to understand the difference between supply only and supply and install, as the total cost varies significantly between the two.
Supply Only
With supply only, you receive the sealed glass unit and handle the fitting yourself – or have your own glazier or installer carry out the work. This is the most cost-effective route if you're a competent DIYer, a trade professional, or if you already have someone lined up to do the installation. All the prices listed in the tables above are supply-only prices.
Supply only is ideal for:
- Trade customers (glaziers, window installers, builders, property maintenance firms)
- Landlords managing multiple properties with their own maintenance team
- Confident DIYers who have replaced sealed units before
If you're not sure how to measure your existing units for a supply-only order, our measuring guide walks you through the process step by step.
Supply & Install
With supply and install, we take care of everything – measuring, manufacturing, delivering, and fitting the new sealed units into your existing frames. Installation labour typically adds £80–£160 per unit for standard replacements carried out at ground-floor level with good access. Costs may be higher for:
- First-floor or above installations requiring scaffolding or ladders
- Difficult access (conservatory roofs, bay windows, high-level fanlights)
- Very large or heavy units that require two-person handling
- Removal and disposal of old units with failed seals
All our installations are carried out by our qualified engineers and come with a full guarantee. Learn more about our installation service.
Which Option Is Right for You?
If your frames are in good condition and you simply need the glass replaced, supply only is the most affordable choice – especially if you have a glazier you trust. If you'd prefer a hassle-free, fully guaranteed job from start to finish, supply and install gives you complete peace of mind. Either way, get a free quote and we'll price both options for you.
Frequently Asked Questions About Double Glazing Costs
A standard 4-16-4 air-filled double glazing unit starts from around £70 for a small 500 × 500 mm size. Prices increase with unit size – expect to pay from £90 for 600 × 900 mm, £110 for 800 × 1200 mm, and £150–£190 for larger units up to 1200 × 1800 mm. These are supply-only prices; upgrading the glass type or gas fill will add to the cost. Contact us for an exact personalised quote.
In most cases, replacing just the sealed glass unit is significantly cheaper than replacing the entire window (frame and all). A replacement sealed unit might cost £70–£190 for the glass plus £80–£160 for installation, compared to £600–£1,600+ for a full window replacement including the frame. If your frames are in good condition – whether uPVC, aluminium, or timber – replacing only the glass unit is the most cost-effective option. See our misted units page for more information on when glass-only replacement makes sense.
Yes. We offer competitive trade pricing with volume discounts for glaziers, window installers, builders, and property maintenance companies. Trade accounts include bulk pricing, priority manufacturing, dedicated account management, and credit terms (subject to approval). Visit our trade page or contact us to set up a trade account.
The main additional costs to consider are delivery (free on orders over £300 otherwise a small delivery charge applies), installation labour if you choose our supply and install service (typically £80–£160 per unit for standard replacements), and any specialist requirements such as bespoke shapes, toughened or laminated glass, or premium gas fills. We always provide a fully transparent quote with no hidden charges – request your free quote to see an exact breakdown.