Choose Windows and Doors — Triple Glazing Pays Back in 12–18 Years, Double Is Good Enough on Most Irish Sites
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Triple-glazed alu-clad timber: U-value 0.7–1.0, €800–€1,400/m² of window. Double-glazed uPVC: U-value 1.2–1.4, €450–€750/m².
When this matters most
You're specifying the window schedule at detailed design, or you're retrofitting windows on a finished house.
When this doesn't apply
Glass is in. We're past first fix.
Frequently asked questions
Is triple glazing worth it in Ireland?
Depends on BER target. For A1, yes. For A2 or A3, double glazing with good frames can be enough.
How much do windows cost?
Double-glazed uPVC: €450–€750/m² installed. Triple-glazed alu-clad: €1,000–€1,500/m². A 30 m² window schedule = €13,500–€45,000.
What U-value do windows need for Part L 2022?
1.4 W/m²K maximum (backstop). For A1 BER: 0.8–1.2 typical.
Timber, uPVC, or aluminium?
Timber: looks best, repaint every 8–12 years. uPVC: cheapest, zero maintenance. Aluminium: longest-lasting frame, slim sightlines, premium.
Are sliding doors as warm as bifold?
Modern triple-glazed sliders are within 0.2 W/m²K of bifolds — both can hit A1 BER.
Sources
NSAI, I.S. EN ISO 10077 — Thermal performance of windows, doors and shutters. https://www.nsai.ie/
SEAI, Window performance database. https://www.seai.ie/
Your options at a glance
Double-glazed uPVC
Standard uPVC frames with double glazing. The default for most Irish new builds. Cheap, low-maintenance, good enough for most BER A2–A3 sites.
- Cost
- €450–€750/m² of window
- U-value
- 1.2–1.4 W/m²K (WER C)
- Maintenance
- Almost none
- BER ceiling
- A2 with good fabric
- Lifetime
- 20–30 years
Triple-glazed alu-clad timber
Timber frames with external aluminium cladding and triple glazing. The premium Irish choice — best U-value, longest lifetime, more expensive.
- Cost
- €800–€1,400/m² of window
- U-value
- 0.7–1.0 W/m²K (WER A+)
- Maintenance
- Repaint timber every 8–12 years
- BER ceiling
- A1 / Passive House
- Lifetime
- 30–40 years
Aluminium (triple-glazed)
Slim aluminium frames, triple-glazed. Modern aesthetic, very slim sightlines, more expensive than timber-clad.
- Cost
- €900–€1,500/m² of window
- U-value
- 0.8–1.1 W/m²K
- Maintenance
- Almost none
- BER ceiling
- A1 / Passive House
- Lifetime
- 30+ years
Frequently asked questions
Is triple glazing worth it in Ireland?
Depends on BER target. For A1, yes. For A2 or A3, double glazing with good frames can be enough.
How much do windows cost?
Double-glazed uPVC: €450–€750/m² installed. Triple-glazed alu-clad: €1,000–€1,500/m². A 30 m² window schedule = €13,500–€45,000.
What U-value do windows need for Part L 2022?
1.4 W/m²K maximum (backstop). For A1 BER: 0.8–1.2 typical.
Timber, uPVC, or aluminium?
Timber: looks best, repaint every 8–12 years. uPVC: cheapest, zero maintenance. Aluminium: longest-lasting frame, slim sightlines, premium.
Are sliding doors as warm as bifold?
Modern triple-glazed sliders are within 0.2 W/m²K of bifolds — both can hit A1 BER.
When this matters most
You're specifying the window schedule at detailed design, or you're retrofitting windows on a finished house.
When this doesn't apply
Glass is in. We're past first fix.
Briefs in this stage
11 in-depth answers for this stage of the build. Pick the one that matches your question.
Bifold Doors in Ireland — Cost, U-value, and When They're the Right Choice
Aluminium bifold (3 m, 3 panels): €4,500–€8,500. U-value 1.0–1.4. Open-plan living. Cheaper to operate than a slider on a large opening.
bifold doors IrelandRead brief →
Door Budget for a Self-Build in Ireland — Internal Doors, External Doors, and Ironmongery
Internal doors: €100–€400 each. External: €1,500–€8,000. Ironmongery: €1,500–€3,000. Total for a 150 m² house: €5,000–€15,000.
door budget Ireland self buildRead brief →
Front Door in Ireland — Composite, Timber, Aluminium, and What the BER Counts
Composite front door: €1,500–€3,500. Timber: €2,500–€6,000. Aluminium: €3,000–€8,000. The BER counts every door.
front door Ireland self buildRead brief →
Garage Door in Ireland — Sectional, Roller, or Up-and-Over, and What the BER Counts
Sectional: €1,500–€3,500. Roller: €1,800–€4,000. Up-and-over: €800–€1,800. Insulated if the garage is habitable space.
garage door Ireland self buildRead brief →
Passive House Windows in Ireland — U-value, Frame, and What the Certifier Wants
Passive House windows: U-value 0.7–0.8 W/m²K whole-window. Triple-glazed, timber or alu-clad frame, warm-edge spacer.
passive house windows IrelandRead brief →
Sliding Doors in Ireland — Aluminium Sliders, Lift-and-Slide, and the U-value Trade-Off
Aluminium sliding door (3 m): €3,500–€7,000. U-value 0.8–1.2. Lift-and-slide is the warmest; standard slide is the cheapest.
sliding doors IrelandRead brief →
Triple vs Double Glazing in Ireland — U-value, Cost, and When Triple Pays Back
Triple: U-value 0.7–1.0, €800–€1,400/m² window. Double: U-value 1.2–1.4, €450–€750/m². Pays back in 12–18 years.
triple vs double glazing IrelandRead brief →
Window Cost in Ireland 2026 — Per m², Per Window, and the Full Schedule Budget
uPVC double: €450–€750/m². Triple alu-clad: €1,000–€1,500/m². A 30 m² window schedule: €13,500–€45,000 installed.
window cost Ireland 2026Read brief →
Window Energy Rating in Ireland — What the Label Means and Why It Matters for BER
Window Energy Rating (WER): A+ to E scale. The whole-window U-value is what counts for BER, not the glass alone.
window energy rating IrelandRead brief →
Window Frame Material in Ireland — uPVC, Timber, Aluminium, and Alu-Clad Compared
uPVC: cheapest, zero maintenance, dated 25 years in. Timber: looks best, repaint every 8–12. Aluminium: longest-lasting, premium.
window frame material IrelandRead brief →
Window Installation in Ireland — Cavity Closer, Dpc, and the Airtightness Detail
Window installation matters as much as the window. Cavity closer, dpc, expanding foam, and a continuous airtightness tape.
window installation IrelandRead brief →
Where to go next
Next decision
The next step in your build sequence.
- Door Budget for a Self-Build in Ireland — Internal Doors, External Doors, and Ironmongery →
- Front Door in Ireland — Composite, Timber, Aluminium, and What the BER Counts →
- Garage Door in Ireland — Sectional, Roller, or Up-and-Over, and What the BER Counts →
- Passive House Windows in Ireland — U-value, Frame, and What the Certifier Wants →
- Sliding Doors in Ireland — Aluminium Sliders, Lift-and-Slide, and the U-value Trade-Off →
- Window Energy Rating in Ireland — What the Label Means and Why It Matters for BER →
- Window Installation in Ireland — Cavity Closer, Dpc, and the Airtightness Detail →
Branch into
Adjacent decisions at the same stage.
Watch out for
Common mistakes, hidden costs, gotchas.
Compare with
Alternative approaches worth knowing.