Triple glazed windows for Irish winters
Three panes, two insulating gas fills and a composite frame. Triple glazed windows keep the warmth in, the noise out and the cold off the glass, so every room is comfortable right up to the window.
Is triple glazing worth it in Ireland?
For new builds and deep retrofits, yes. Our climate is mild but damp, which means long heating seasons rather than extreme cold. A window that loses less heat lets you run a lower heating load, and a warmer inside surface means far less condensation on the glass.
Triple glazing is also a stepping stone to near-zero energy and Passivhaus standards. Internorm quotes whole-window Uw values as low as 0.62 W/m²K, which is a Passive House level of performance. Use the glazing lab below to see what that means for the temperature of the glass in your own room.
We have written a plain-English answer to the full question in our guide: Is triple glazing worth it in Ireland?
Why the whole window matters, not just the glass
Many suppliers quote Ug, the U-value of the glass alone. The figure that decides comfort and energy use is Uw, the value for the whole window including frame and the edge of the glass. Internorm frames are densely packed with insulating laminates, so there are no air-filled voids where heat can escape.
The SOLAR+ coating also lets more of the sun's energy in, so south-facing glass works as free heating on bright winter days. Ask us for the Uw values of the exact windows we are specifying for your house.
- Up to 40% more glazed area for the same heating cost, compared with double glazing, according to Internorm
- About 10% more daylight from the premium glass coating
- Glass, frames and toughened panes made in Internorm's own factories
What triple glazing changes in your home
Warmer glass
The inside pane stays close to room temperature, so there is no cold draught off the window.
Less condensation
A warmer inner surface means far fewer misted windows on cold mornings.
Quieter rooms
Three panes and gas fills soften road, rain and neighbour noise.
More free solar heat
SOLAR+ glazing lets in about 20% more solar energy than standard triple glazing, per Internorm.
Lower running costs
Less heat loss means lower bills, in the house you already own or the one you are building.
Passivhaus pathway
Meets the performance needed for Passivhaus and near-zero energy projects.
Feel the difference the glass makes
Pick a type of glazing, then drag the outside temperature. The sliders show how warm the inside pane stays, how much heat leaves each square metre, and when condensation starts to form.
- A cold inner pane is what you feel as a draught
- Moisture condenses on the coldest surface in the room
- Triple glazing keeps that surface close to room temperature
- Inner pane
- 19.3°C
- Heat loss
- 17W per m²
- Whole-window U
- 0.8W/m²K
Indicative, from standard surface resistance (0.13 m²K/W) and typical whole-window U-values: single 5.0, older double 2.8, modern double 1.4, triple 0.8. Internorm quotes Uw as low as 0.62 on selected models.
What could better glazing save you?
A rough guide to the heat your windows lose in a normal Irish year, and how much of it triple glazing could save. Change the numbers to match your house and your latest bill.
An estimate, not a quote or a guarantee. It looks at heat lost through the glazing only, using typical whole-window U-values and about 2,100 heating degree days a year. Your survey will give exact figures.
- Heat lost through glazing now
- 0 kWh a year
- With triple glazing (Uw 0.8)
- 0 kWh a year
- Possible saving
- €0 a year
Models we supply
Internorm HF 510
Timber warmth inside, aluminium protection outside, in the Home Pure style.
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Internorm HF 410
The most versatile Internorm timber-aluminium window, in all four design styles.
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Internorm HV 450
A timber-aluminium window in the Ambiente, Home Soft and Home Pure styles.
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Internorm KF 510
A maintenance-free uPVC-aluminium window with a square-edged Home Pure look.
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Internorm KF 410
The popular all-rounder: uPVC-aluminium or full uPVC in four design styles.
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Internorm KF 310
Strong thermal performance in Home Soft, Ambiente and Home Pure styles.
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Internorm KV 440 with integrated blinds
Sun and privacy protection built between the panes.
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Internorm KF 520 Studio
Flush, minimalist and engineered for striking architecture.
View detailsIn their words
Real feedback from EWC customers, published on our reviews page.
“The fitting team were one of the most professional we have had onsite in the many years we have owned our house. Overall EWC offer a premium product in Internorm and their service matches the product.”Ian and Ann, Carlow2024 refurbishment
“The installation team did an amazing job and took time to ensure they were 100% happy and did not rush at any stage. The front door in particular has drawn comment from subsequent visitors.”Michael Russell, Dublin2024 new build
“The team take the time to listen to and understand the customer's needs with no hard sell. Our windows and doors fitted without any hassle and are super efficient and virtually soundproof.”Martin and Sile, Carlow2024 new build, DAKO triple-glazed uPVC
Triple-glazed windows: your questions answered
What is the difference between Ug and Uw?
Ug is the U-value of the glass only. Uw is the U-value of the whole window, including the frame and the edge of the glass, so it is the figure to compare when choosing windows. Lower is better.
Are triple glazed windows too heavy or too thick for my house?
Internorm builds triple glazing into slim composite frames, so most openings can be fitted without changing the structure. We survey on site and confirm before ordering.
Will triple glazing stop condensation?
It greatly reduces it on the glass, because the inside pane stays warmer. Good ventilation still matters, and Internorm offers i-tec ventilation that fits into the frame.
How much do triple glazed windows cost in Ireland?
Price depends on size, frame material, number of openings and finish. We prepare a tailored quote after a survey or from your plans, with no obligation. See our guide to what new windows cost.
Get a triple glazed windows quote
Send your plans or a rough list of openings and we will come back within one working day.
- Reply within one working day
- Advice that fits your build type and budget
- Showroom visits welcome, by appointment