Double glazed windows in Ireland typically cost between £450 and £1,200 per window fitted, depending on size, frame material and glass type, according to the Energy Saving Trust which notes that uPVC frames are the most common and affordable option (Energy Saving Trust, 2026).
The final price varies significantly by frame material: uPVC averages £450–£800 per window, aluminium £700–£1,200, and timber £800–£1,500. Double glazing reduces heat loss by up to 50% compared to single glazing, with a typical U-value of 1.2–1.6 W/m²K for modern units (GOV.UK Building Regulations Approved Document L, 2026). Costs also depend on window style, casement windows are cheaper than sliding sash or bay windows. Installation fees are usually included in the quote, but always check for removal and disposal charges.
uPVC double glazed windows cost £450 to £800 each
uPVC frames are the cheapest option, with a standard 1.2m x 1.2m casement window costing around £500–£700 fitted. Energy Saving Trust states that uPVC is low-maintenance and provides good thermal performance, with a typical U-value of 1.4 W/m²K (Energy Saving Trust, 2026). Larger windows or those with decorative glass add £100–£300. uPVC is the most popular choice in Ireland due to its balance of cost and durability.
Aluminium double glazed windows cost £700 to £1,200 each
Aluminium frames are stronger and slimmer. This allows larger glass areas, but cost more. A standard 1.2m x 1.2m aluminium casement window runs £800–£1,000 fitted, with higher costs for thermal break designs. The Building Regulations require a whole-window U-value of 1.6 W/m²K or lower for new installations (GOV.UK Building Regulations Approved Document L, 2026). Aluminium is popular for modern homes but is more expensive than uPVC.
Timber double glazed windows cost £800 to £1,500 each
Timber windows offer the best insulation but are the priciest. A standard 1.2m x 1.2m softwood casement window costs £800–£1,100 fitted, while hardwood versions reach £1,200–£1,500. The Energy Saving Trust notes that timber frames can achieve U-values as low as 1.1 W/m²K (Energy Saving Trust, 2026). They require regular painting or staining every 3–5 years, adding long-term maintenance costs. Timber is best suited to period properties or conservation areas.
A worked example
A typical 1930s semi-detached house in Dublin with 10 standard uPVC double glazed windows (1.2m x 1.2m casements) costs around £6,000 fitted after the SEAI Better Energy Homes grant of up to £700 per home. The Energy Saving Trust estimates yearly heating savings of £195 on a typical gas-heated home, giving a payback period of roughly 31 years on the net cost. Over 25 years, total savings reach £4,875, though the main benefits are comfort and noise reduction rather than a fast financial return. Larger homes with 14 windows or bay windows can expect costs of £8,000 to £10,000, with aluminium or timber frames pushing the total higher. The SEAI grant covers attic insulation and heating controls too, so combining measures improves overall value.
| Item | Figure |
|---|---|
| Upfront cost after grants | £6,000 |
| Yearly savings | £195 |
| Payback period | 31 years |
| 25-year lifetime savings | £4,875 |
What homeowners often get wrong
The most common mistake is assuming the cheapest quote delivers the best value without checking U-values or installation standards. Here are three frequent errors that cost Irish homeowners money and comfort.
- Ignoring U-values when comparing quotes Many buyers focus only on price, but a window with a U-value of 1.6 W/m²K loses more heat than one rated 1.2 W/m²K. Over a 25-year lifespan, the less efficient option can cost an extra £400 in heating bills, wiping out any upfront saving.
- Skipping the SEAI grant application Some homeowners assume the paperwork is too complicated or that they are ineligible. The SEAI Better Energy Homes grant offers up to £700 per home for window upgrades, and missing it means leaving free money on the table, enough to cover one or two windows entirely.
- Choosing the wrong frame material for the climate Timber frames look attractive but require regular painting in Ireland’s damp weather, adding £150–£300 in maintenance every five years. uPVC or aluminium with a thermal break are more practical, lasting 25–35 years with minimal upkeep.
Quick reference
- uPVC double glazed windows in Ireland cost £450 to £800 each fitted, with aluminium at £700 to £1,200 and timber at £800 to £1,500.
- Double glazing reduces heat loss by up to 50% compared to single glazing, with a typical U-value of 1.2 to 1.6 W/m²K for modern sealed units.
- The SEAI Better Energy Homes grant covers up to £700 per home for window upgrades, with no income threshold for eligibility.
- Payback on double glazing alone is typically 25 to 35 years, but combining it with attic insulation can cut the payback to 10 to 15 years.
- Always check that installers are registered with the National Standards Authority of Ireland (NSAI) to avoid voiding warranties on the glass and frames.
Frequently Asked Questions
uPVC double glazed windows in Ireland cost £450 to £800 each fitted, according to the Energy Saving Trust. A standard 1.2m x 1.2m casement window averages £500–£700.
Yes, aluminium double glazed windows cost £700–£1,200 each fitted, compared to £450–£800 for uPVC. Energy Saving Trust notes aluminium is stronger and slimmer but pricier.
Timber double glazed windows in Ireland cost £800 to £1,500 each fitted. GOV.UK Building Regulations state modern units achieve a U-value of 1.2–1.6 W/m²K.
