How Much Do Double Glazed Windows Cost?

Double glazed windows are a staple in UK homes, renowned for their energy efficiency, noise reduction, and enhanced security. Featuring two panes of glass separated by a layer of gas or air, they provide superior insulation compared to single glazing. In 2025, with advancements in glazing technology and frame materials, double glazed windows are a smart choice for modern and traditional properties alike. This guide explores their costs, benefits, and key factors to consider for installation or replacement in the UK.

Double glazed windows often work silently in the background—until condensation builds, seals fail, or energy bills spike. Calculating their replacement cost involves juggling variables like size, frame material, and labour. Whether you’re aiming to cut heating costs or boost comfort, understanding the pricing is crucial.

Typical Double Glazed Window Costs by Size

The cost of double glazed windows depends on their dimensions and frame type. Below is a table showing typical sizes and cost ranges in the UK for 2025 (including standard installation):

Width (mm)	Height (mm)	Style	Cost Range (uPVC)	Cost Range (Aluminium)
600	900	Casement	£200-£350	£300-£450
900	1200	Casement	£300-£500	£400-£600
600	1200	Double Hung	£300-£450	£400-£550
1200	1500	Double Hung	£450-£700	£550-£800

In the UK, double glazed window costs typically range from £200 to £800 per window, depending on size, style, and material. These windows excel at keeping homes warm, but over time, seals can degrade, and weather—rain, wind, or frost—can wear them down. If yours are fogging up or letting in noise, replacement might be on the cards.

Material Cost Comparison

Before opting for double glazed windows, it’s wise to dig into the specifics. What’s the installation cost, and which material best suits your home? Your decision hinges on budget, durability, and appearance. Here’s a table comparing materials for a standard 900mm x 1200mm casement double glazed window:

Material	Cost Range	Pros	Cons
uPVC	£300-£500	Affordable, low maintenance	Less stylish
Aluminium	£400-£600	Durable, slim frames, modern	Less insulating, costlier
Timber	£550-£800	Elegant, great insulation	Needs regular upkeep

How much do double glazed windows really cost? Beyond size and material, extras like gas-filled panes (e.g., argon) or custom finishes can raise the price. uPVC dominates for its affordability, while timber appeals to those valuing aesthetics and insulation. Aluminium offers a sleek, contemporary option.

Factors Affecting Double Glazed Window Costs

Thinking of repairs instead? A failed seal or cracked pane might not mean a full replacement—repairs typically range from £80-£200, depending on the issue. But if insulation is poor or noise is seeping in, new double glazing could be the smarter move. Here’s what drives their cost:

Factor	Description	Impact on Cost
Size	Larger windows require more glass and framing	Adds £100-£200 per size jump
Gas Filling	Argon or krypton between panes	£20-£50 extra per window
Material	uPVC, aluminium, timber	See material table
Labour	£100-£200 per window	Higher in urban areas
Coatings	Low-e or UV-protective coatings	£30-£80 extra per window

Repair or replace? If your double glazing still insulates well and damage is minor, a repair might suffice. But if condensation persists or energy costs are creeping up, replacement offers superior performance. A professional can assess your needs and recommend the best path.

Additional Installation Costs

Choosing double glazed windows is about efficiency and comfort. Want noise reduction or a specific look? uPVC is practical, timber adds warmth, and aluminium fits modern designs. Here’s a breakdown of extra costs:

Expense	Typical Cost	Notes
Removal of Old Window	£50-£150	Varies by condition
Scaffolding	£200-£400	For upper floors
Building Regulations	£100-£150	FENSA certification
Finishing (e.g., trim)	£20-£50 per window	Optional aesthetic work

Materials shape both cost and upkeep—uPVC is low-maintenance, timber requires care for its charm, and aluminium offers durability. Adding gas fillings or low-e coatings boosts efficiency for £20-£80 more per window. A typical replacement might total £350-£1,000 per window with extras.

Return on Investment (ROI)

Double glazed windows deliver energy savings and added value—here’s how:

Benefit	Estimated Savings/Value	Timeframe
Energy Savings	£100-£300/year	Ongoing with proper insulation
Property Value Increase	2-5% of home value	Upon resale
Payback Period	8-12 years	Based on savings and value

Final Thoughts

Double glazed window costs in 2025 range from £200 for a small uPVC unit to £800 for a large timber or aluminium one. Size, material, and installation extras determine the price, but their insulation, noise reduction, and value boost make them a top investment. Secure three quotes from FENSA-registered installers to ensure quality and savings—double glazing is a game-changer for UK homes.