Double vs triple
Double vs triple glazing: which?
Triple glazing costs €150 to €200 more a window (Airtight Window Systems) and loses less heat. It earns its place on north-facing rooms, which the SEAI grant requires anyway (MyHome), and near noise. Good double glazing still does the job on a sunny south wall.
- €7,110the median cost of new windows on a semi-D or end of terrace, January to June 2026 (SEAI)
- €500 to €900a standard uPVC window, installed (Expert Windows & Doors)
- 1 to 3 daysto fit most houses, after the windows are made (Expert Windows & Doors)
- 13.5% VATon windows supplied and fitted, not 23% (Revenue)
FreeNo obligationOne company rings you, not fiveNothing agreed until you accept a written price
Side by side
Double and triple
| Double glazing | Triple glazing | |
|---|---|---|
| Panes | Two | Three |
| 10-window 3-bed semi, uPVC (Airtight) | €6,000 to €8,000 | €7,500 to €10,000 |
| Installed, a m² of uPVC (PPI) | €450 to €750 | €650 to €950 |
| SEAI grant | Allowed except facing north | Required facing north |
| Weight | Lighter | Heavier sashes and hinges |
(Airtight Window Systems, Planning Permission Ireland, MyHome). Airtight's house prices carry no VAT label; PPI doesn't say.
Where it pays
Where triple pays
- North-facing rooms, which get no winter sun through the glass.
- Near a road, rail or airport: the extra pane helps with noise.
- A well-insulated house on a heat pump, where the windows are now the weakest part.
- Colder parts of the country: see the heating degree days on each county page.
Where it doesn't
Where double is enough
- South-facing glass, which gains free heat on sunny winter days.
- A house with uninsulated walls and attic: fix those first.
- A tight budget: a good double-glazed window with a low U-value beats a poor triple one.
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New windows on your own photo
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- Upload a photo, or answer 4 questions.
- We pass it to one company that covers your county.
- They ring you to measure up and price it in writing.
Preview of your photo, not a guarantee. Your photo goes to Google's Gemini service to make the picture and isn't kept.
A photo that works
- Daylight, from the footpath or the garden.
- The whole front of the house in the shot.
- Straight on, not at a sharp angle.
- No cars or bins in front of the windows, if you can help it.
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FAQ
Questions people ask
Is triple glazing better than double?
It loses less heat and keeps the inside of the glass warmer. Whether it's worth the extra depends on the room's direction, noise and the rest of the house.
Can I mix double and triple glazing?
Yes, many houses do: triple on the north side, double elsewhere. That's also how the SEAI rule is written, as MyHome reports it.
Does triple glazing stop condensation?
It cuts condensation on the glass, because the inner pane stays warmer. Condensation from a damp house still needs ventilation.
Keep reading
Related guides
Where these numbers come from (3 public sources, checked 3 November 2026)
Sources (3)
Prices and facts on this page were checked against these published pages. We are not connected to these businesses.
- Airtight Window Systems: airtight.ie
- Expert Windows & Doors: expertwindows.ie
- Planning Permission Ireland: planningpermissionireland.ie