Replacement Double Glazing Units
Made-to-Measure Sealed Units, Supplied UK-Wide
The cost-effective fix for misted, blown or failed double glazing units. We manufacture made-to-measure replacement sealed units for homes, landlords and trade across the UK — energy-efficient Low-E, toughened and acoustic glass, precision-built to BS EN 1279 and delivered in 5–7 working days.
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Brilliant service, saved us a fortune
Sealed units arrived within the week and were a perfect fit. Saved a fortune compared to ripping out the whole window. Can't fault them at all – would definitely use again.
Our go-to supplier for trade
We've been using these guys for about two years now on all our renovation jobs. Consistent quality, decent prices, and they actually deliver when they say they will. The argon Low-E units are spot on.
Misted units sorted in a day
Our Victorian terrace had misted windows all over the house. They replaced all 12 sealed units in one day and didn't touch the original timber frames. Massive difference in warmth – wish we'd done it sooner.
Helpful team, got the sizes sorted
I measured up wrong initially (my own fault) and gave them the wrong dimensions. Rang up, spoke to a really helpful bloke who walked me through measuring properly. Replacement units arrived bang on size. Top marks.
Great value for landlords
I've got six flats and needed sealed units across most of them. The trade pricing was genuinely competitive and they handled the whole lot without any fuss. Already booked them for another property.
Good product, delivery slightly slow
The sealed units themselves are excellent quality – no complaints there at all. Delivery took a day longer than expected which was a bit annoying as I had a fitter booked. But the end result is great.
Bay window looks brand new
Had a large bay window with a blown unit that was driving me mad. They came out, measured up, and fitted the replacement sealed unit within the week. Looks like a brand new window. Absolutely chuffed.
Whole house done, really pleased
We had every window in the house done – 14 units in total. They quoted quickly, delivered on time, and the fitter was neat and professional. Noticeably warmer already and our energy bill has dropped.
Conservatory units replaced perfectly
The conservatory roof panels had all misted up and it looked awful. Got all the sealed units swapped out and it's like having a brand new conservatory. Really happy with the result and the price was reasonable.
Reliable supplier, been using them for years
As a trade installer I need a supplier I can rely on and these lot haven't let me down yet. Good communication, quality products, and they understand the trade side of things. Wouldn't go anywhere else now.
Argon fill made a huge difference
Went for the argon-filled Low-E units on the recommendation of their team and the difference is night and day. The front bedroom used to be freezing in winter – now it's the warmest room in the house. Worth every penny.
Good product, website could be easier
The actual double glazing unit is excellent and fits perfectly. Only reason for four stars is the website could be a bit easier to navigate when choosing options. But the product and service? No complaints.
Bathroom window sorted quickly
Had a misted bathroom window that had been bugging me for months. Rang up on Monday, unit was delivered Friday, and my local handyman fitted it in 20 minutes. Crystal clear again. Dead easy process.
Perfect for our period property
We needed slimline units for our Edwardian semi because the rebates are quite narrow. They recommended the right spec and the units fit perfectly into the original frames. The house looks exactly as it should – just much warmer.
Use them on every job now
I'm a builder and I've tried a few different sealed unit suppliers over the years. These are the ones I stick with. Fair trade prices, they don't mess you about on lead times, and the quality is consistently good.
No more condensation!
Our kitchen window always had condensation running down it every morning. Got the sealed unit replaced with a Low-E argon unit and it's completely gone. Should have done it ages ago. Quick and painless service too.
Quick turnaround, impressed
Ordered on a Tuesday, units arrived the following Monday. For bespoke sizes that's really quick. Fitted them myself – straightforward job. Glass quality is excellent and the seal looks solid. Very impressed overall.
Great product, tracking could be better
Units are really good quality and the price was fair. Had to chase up the delivery tracking a couple of times as it wasn't updating. Once they arrived though, perfect fit and they look great. Would still recommend.
Road noise practically gone
We live on a busy main road and the old single-pane windows were useless. Upgraded to their acoustic sealed units and the difference is unbelievable. Can finally have a proper night's sleep. Money well spent.
10 windows done, faultless
Had 10 sealed units replaced across the front and back of the house. Every single one was the correct size, delivered on the day they said, and fitted without any problems. Really professional outfit from start to finish.
Why Choose Double Glazing Units?
For over 20 years we've manufactured precision sealed units in the UK, trusted by homeowners, landlords and trade installers nationwide. Every unit is made to order and built to last.
20+ Years' Experience
Two decades manufacturing double glazing sealed units at our own London facility — not a middleman, but the maker. That expertise means the right glass spec, first time, every time.
BS EN 1279 & BSI Kitemark
Every sealed unit is manufactured to BS EN 1279 standards with a minimum 90% gas fill, fully compliant with Building Regulations Part L and backed by BSI Kitemark quality assurance.
Rated Excellent — 247 Reviews
Homeowners, landlords and trade customers rate us Excellent across 247 reviews for quality, fair pricing and reliable lead times. Read what our customers say above.
10-Year Guarantee
We're so confident in our manufacturing that every double glazing unit is covered by a comprehensive 10-year guarantee against seal failure and misting.
Double Glazing Units Built to Your Exact Specification
We specialise in manufacturing and supplying high-performance double glazing units for both residential and commercial properties across the United Kingdom. With over 20 years of experience, every double glazing sealed unit is precision-built at our London facility to meet BS EN 1279 standards and carries a 10-year guarantee. Whether you need a single replacement for a misted or blown unit, energy-efficient Low-E glazing, toughened safety glass or acoustic units, we supply made-to-measure sealed units nationwide with fast, reliable delivery direct to your door. Not sure on sizes? Our measuring guide walks you through it, and our cost guide gives a full UK price breakdown.
We manufacture and deliver double glazing sealed units directly to your door. Standard and bespoke sizes, trade and retail, with UK-wide delivery.
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Full service – we measure, manufacture, deliver, and install your new sealed units. All work carried out by our qualified installers.
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Fast response for smashed or damaged sealed units. We offer a board-up and replacement service to secure your property quickly.
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From enquiry to installation in five simple steps – with expert guidance and fast turnaround at every stage.
Get in Touch
Call, email, or fill in our quick online form with your requirements.
Free Quote
Receive a detailed, no-obligation quote within 2 hours.
Manufacture
Precision-built to BS EN 1279 standards using Pilkington glass.
UK Delivery
Securely packaged and delivered to your door nationwide.
Installation
Professional fitting backed by our 10-year warranty.
Our Double Glazing Unit Types
We supply a comprehensive range of double glazed sealed units to suit every requirement and budget.
Energy-efficient low emissivity glass that reduces heat loss whilst allowing natural light in. Ideal for meeting Building Regulations Part L.
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BS EN 12150 compliant toughened safety glass, required for doors, low-level windows, and areas near baths or showers under UK regulations.
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Specialist sound-reducing sealed units using asymmetric glass configurations to significantly reduce external noise – perfect for busy roads.
View DetailsGas-Filled Sealed Units for Superior Insulation
The gas fill inside your sealed unit makes a significant difference to thermal performance. Argon gas is the most popular choice for UK homes, offering around 34% better insulation than air-filled units at an affordable price.
For heritage properties requiring slimline units, krypton gas delivers excellent performance in narrower cavities. We also offer xenon gas for specialist commercial applications.
All our gas-filled units are manufactured to BS EN 1279-3 standards with a minimum 90% gas fill level, ensuring long-lasting thermal efficiency and compliance with Building Regulations Part L.
Compare Gas Fills
Why Do Double Glazing Units Fail? Misting, Condensation & Blown Seals
Understanding why sealed units fail helps you fix the problem properly — and avoid paying for a full window replacement you don't need.
A double glazing unit is two (or three) panes of glass separated by a spacer bar and sealed around the edge, with the cavity filled with dry air or insulating gas such as argon. Over time, the perimeter seal can break down. When it does, moisture works its way into the cavity and you get the tell-tale signs of a failed or "blown" unit.
The most common symptom is misting or condensation trapped between the panes — a foggy haze you can't wipe away because it's sealed inside the glass. You may also notice a permanent watermark, streaking, or a visible drop in how warm the room feels. Once a seal has failed, the insulating gas escapes and the unit's thermal performance falls sharply.
The good news: in the vast majority of cases you only need to replace the sealed glass unit, not the whole window. If your uPVC, aluminium or timber frame is sound, we manufacture a made-to-measure replacement unit that drops straight into the existing frame — typically fitted in under an hour. It's far cheaper than a new window and just as effective. Learn more on our dedicated misted & failed units page.
Signs Your Double Glazing Needs Replacing
- Misting or fog between the panes that won't wipe off
- Condensation inside the glass, especially in the morning
- Visible watermarks, streaks or a "rainbow" sheen
- Rooms feeling colder or higher heating bills
- Draughts, or the glass feeling cold to the touch
- Cracked, chipped or smashed panes (we offer emergency replacement)
Spotted one or more of these? It almost certainly means the seal has gone. Send us your sizes for a free, no-obligation quote on a replacement unit.
How Much Do Replacement Double Glazing Units Cost?
Double glazing unit prices depend on the size, glass type and gas fill you choose. The guide prices below are a typical UK starting point for supply-only sealed units — for an exact figure, request a free quote or see our full cost guide.
| Unit Type | Small (up to 500×500mm) | Medium (up to 1000×1000mm) | Large (up to 1500×1200mm) |
|---|---|---|---|
| Standard Clear Unit | from £70 | from £110 | from £165 |
| Low-E Energy Efficient (Argon) | from £85 | from £135 | from £195 |
| Toughened Safety Glass | from £95 | from £155 | from £225 |
| Acoustic Noise-Reducing | from £115 | from £185 | from £265 |
Prices are a guide for supply only and exclude VAT and delivery (free on orders over £300). Bespoke shapes, triple glazing, krypton-filled slimline units and decorative glass are quoted individually. Replacing only the sealed unit rather than the whole window typically saves 50–70% versus a full window replacement.
How to Measure for a Replacement Sealed Unit
Ordering a made-to-measure double glazing unit is straightforward once you know the three numbers we need: the width, the height and the overall unit thickness (the combined depth of both panes plus the spacer, e.g. 24mm or 28mm).
- Measure the visible glass (the "sight size") with the window closed, then add roughly 10mm to each dimension to reach the true unit size that sits inside the rebate.
- Measure the thickness by looking at the edge of the glass — or read it off the metal spacer bar, which is often stamped with the cavity width.
- Check the glass type — some windows legally require toughened safety glass (doors, low-level and bathroom windows under UK Building Regulations).
- Send us your sizes and we'll confirm everything before manufacture.
Our step-by-step measuring guide includes diagrams, or if you'd rather not measure yourself, our supply & install team will survey and fit for you.
View the Measuring Guide
Areas We Cover
We supply and install double glazing units across London and the entire United Kingdom.
Frequently Asked Questions
Double glazing unit prices vary depending on size, glass type, and gas fill. Standard sealed units start from around £70 for smaller sizes (500×500mm). Low-E and toughened options cost more. Visit our cost guide for a full UK price breakdown, or get a free quote for exact pricing on your requirements.
Standard sealed units are typically manufactured and delivered within 5–7 working days. Bespoke sizes, specialist glass types, or specific gas fills may take 10–14 working days. We deliver across the entire United Kingdom, with free delivery on orders over £300.
Yes. We offer trade accounts with competitive bulk pricing, dedicated account management, priority manufacturing, and credit terms (subject to approval). Whether you're a builder, window installer, or property developer, we have a trade solution that works for you.
For most UK homes, argon gas is the best balance of performance and cost, improving insulation by around 34% compared to air-filled units. Krypton gas is ideal for slimline units in heritage or listed buildings where a narrow cavity is required. Visit our gas fills page for a full comparison.
In most cases, yes. If your window frames are in good condition – whether uPVC, aluminium, or timber – we can replace just the sealed glass unit without touching the frame. This is far more cost-effective than a full window replacement and typically takes under an hour per unit.
We supply double glazing units nationwide across the UK. Our installation service covers London, the South East, Midlands, and most major UK cities. For areas outside our installation network, we offer supply-only with UK-wide delivery. Check our areas we cover page for details.
The clearest sign is misting or condensation trapped between the panes that you can't wipe away – this means the edge seal has failed and the unit is "blown". Other signs include watermarks or streaks inside the glass, rooms feeling colder, and rising heating bills. In almost all cases you only need to replace the sealed glass unit, not the whole window. See our misted & failed units guide for more.
You'll need three measurements: the width, the height and the overall thickness (typically 24mm or 28mm). Measure the visible glass with the window closed and add around 10mm to each dimension to reach the true unit size. Our step-by-step measuring guide includes diagrams, or our team can survey and fit for you.
A quality sealed unit typically lasts 15–20 years before the seal eventually degrades. Units manufactured to BS EN 1279 standards with a proper desiccant-filled spacer last considerably longer than budget alternatives. Every unit we make is backed by a 10-year guarantee against seal failure and misting.
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