Roof Windows in Ireland — Velux, Keylite, and Fakro, Cost and Where to Use Them

Roof windows (Velux, Keylite, Fakro) in Ireland: €1,200–€2,500 installed per window, including flashing. Cheapest daylight on a 1½-storey house. Far cheaper than a dormer (€5,000–€15,000 each). Standard sizes: 550×980 mm, 780×980 mm, 940×980 mm, 1140×980 mm. Centre-pivot or top-hung. U-value 1.0–1.4 W/m²K for double-glazed; 0.7–1.0 for triple-glazed. Most self-builds use Velux (the most common brand, broadest range). Keylite is a UK/Irish brand with a slightly cheaper price point. Fakro is a European brand with good technical specs. All three have similar U-values and lifespans.

TL;DR

• Roof window (Velux, Keylite, Fakro) in Ireland: €1,200–€2,500 installed per window, including flashing.

• Cheapest daylight on a 1½-storey house. Far cheaper than a dormer (€5,000–€15,000 each).

• Standard sizes: 550×980 mm, 780×980 mm, 940×980 mm, 1140×980 mm. Centre-pivot or top-hung. U-value 1.0–1.4 W/m²K for double-glazed.

When this matters most

You're at design stage and need daylight in a stairwell or upstairs room.

When this doesn't apply

You've already specified the roof windows.

Frequently asked questions

How much does a Velux cost in Ireland?

€1,200–€2,500 installed per window, including flashing. Cheaper than a dormer. Triple-glazed is €300–€500 more than double-glazed.

What is the cheapest way to add daylight upstairs?

Roof window (Velux). €1,200–€2,500 installed. Cheaper than a dormer (€5,000–€15,000 each) and easier to install.

Velux, Keylite, or Fakro?

Velux is the most common in Ireland, broadest range. Keylite is a UK/Irish brand, slightly cheaper. Fakro is a European brand, good technical specs. All three have similar U-values and lifespans.

Sources

Velux Ireland, Product range and prices. https://www.velux.ie/

Building Regulations 2023, TGD-L. https://www.gov.ie/