Bifold Doors in Ireland — Cost, U-value, and When They're the Right Choice
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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.
Aluminium bifold door (3 m, 3 panels) in Ireland: €4,500–€8,500 installed. U-value 1.0–1.4 W/m²K for double-glazed; 0.9–1.2 for triple-glazed. Open-plan living — full opening when the doors fold back. Cheaper to operate on a large opening than a slider (each panel is lighter). Triple-glazed bifolds can hit BER A1. Most common in Irish self-builds on the south or west elevation. The opening size matters: a 3-panel bifold needs 3 m of clear wall; a 5-panel needs 5 m. Threshold detail: most Irish self-builds use a low threshold (15–25 mm step) for indoor-outdoor flow; a flush threshold (level with the inside floor) costs more but is best for accessibility.
When this matters most
You're considering a bifold door for indoor-outdoor flow.
When this doesn't apply
You've already specified the door.
Sources
NSAI, I.S. EN ISO 10077. https://www.nsai.ie/
Frequently asked questions
How much do bifold doors cost in Ireland?
Aluminium bifold (3 m, 3 panels): €4,500–€8,500 installed. Triple-glazed: add €500–€1,500. 5-panel: €7,000–€14,000.
What is the U-value of a bifold door?
Double-glazed: 1.0–1.4 W/m²K. Triple-glazed: 0.9–1.2. Can hit BER A1 with the right frame and glazing.
Bifold or sliding door?
Bifold for full opening (panels fold back, indoor-outdoor). Slider for partial opening (one panel slides behind the other). Slider is warmer per m²; bifold is cheaper to operate on a large opening.
When this matters most
You're considering a bifold door for indoor-outdoor flow.
When this doesn't apply
You've already specified the door.
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.