How Much Do Bay Windows Cost?

Bay windows are a timeless addition to UK homes, projecting outward to create extra space, light, and a striking architectural feature. Popular for their elegance and versatility, they suit both traditional and modern properties. In 2025, with improved glazing and material options, bay windows remain a top choice for homeowners looking to elevate their living spaces. This guide dives into the costs, styles, and factors to consider when installing or replacing bay windows in the UK.

Bay windows often go unnoticed in daily life—until they leak, crack, or simply age beyond repair. Estimating their replacement or installation cost can feel daunting due to the variety of sizes, styles, and materials involved. Whether you’re drawn to their charm or their practical benefits, knowing the price breakdown helps you plan this significant upgrade.

Typical Bay Window Costs by Size

The cost of bay windows depends on their dimensions and configuration. Below is a table showing typical sizes, window sections, and cost ranges in the UK for 2025 (including standard installation):

Width (mm)	Height (mm)	Sections	Cost Range (uPVC)	Cost Range (Aluminium)
1800	1200	3	£1,200-£1,800	£1,500-£2,200
2400	1200	3	£1,500-£2,200	£1,800-£2,600
3000	1500	4	£2,000-£2,800	£2,400-£3,200
3600	1500	5	£2,500-£3,500	£3,000-£4,000

In the UK, bay window costs typically range from £1,200 to £4,000, depending on size, material, and complexity. These windows add character, but they’re exposed to the elements—rain, wind, and frost can degrade them over time. If your bay window is draughty or damaged, replacement might be on the horizon.

Material Cost Comparison

Before committing to bay windows, gather the facts. How much will installation cost, and which material fits your home’s style? The right choice balances budget, durability, and aesthetics. Here’s a table comparing materials for a standard 2400mm x 1200mm bay window:

Material	Cost Range	Pros	Cons
uPVC	£1,500-£2,200	Affordable, low maintenance	Less premium look
Aluminium	£1,800-£2,600	Sleek, durable, slim frames	Higher cost, less insulation
Timber	£2,200-£3,000	Classic beauty, good insulation	Needs regular care

How much do bay windows really cost? Beyond material and size, factors like glazing and labour add up. High-end options—like timber with triple glazing—can push costs toward £3,000 or more, while uPVC offers a budget-friendly entry point. Your choice depends on whether you prioritize cost or curb appeal.

Factors Affecting Bay Window Costs

Repairing instead of replacing? A broken pane or warped frame might not demand a full overhaul—repairs typically cost £100-£300, depending on damage. But if energy efficiency or aesthetics are lacking, new bay windows could be the answer. Here’s what influences their cost:

Factor	Description	Impact on Cost
Size & Sections	More sections or larger spans	Adds £300-£500 per section
Glazing	Double vs. triple glazing	Triple glazing adds £150-£400
Material	uPVC, aluminium, timber	See material table
Labour	£200-£500 per installation	Higher in urban areas
Roof Design	Flat, pitched, or custom roof	£200-£600 extra

Repair or replace? If your bay window still functions but looks worn, a repair might suffice. However, rising energy costs or structural issues often tip the scales toward replacement. A professional can help you decide based on your home’s needs.

Additional Installation Costs

Choosing bay windows is about style as much as function. Do you want a cozy reading nook or a grand statement piece? Materials like timber suit period homes, while aluminium fits contemporary designs. Here’s a breakdown of extra costs:

Expense	Typical Cost	Notes
Removal of Old Window	£100-£250	Depends on size and condition
Structural Support	£300-£800	Lintel or foundation work
Building Regulations	£100-£200	FENSA certification
Finishing (e.g., plastering)	£150-£300	Interior/exterior touch-ups

Materials impact both cost and upkeep—uPVC is low-maintenance, timber adds warmth but needs care, and aluminium offers a sleek finish. Glazing options like triple panes or low-e coatings enhance efficiency, adding £150-£400 to the total. A typical 3-section bay window might cost £1,800-£3,000 including extras.

Return on Investment (ROI)

Bay windows boost more than just aesthetics—here’s their value payoff:

Benefit	Estimated Savings/Value	Timeframe
Energy Savings	£75-£250/year	Ongoing with efficient glazing
Property Value Increase	2-5% of home value	Upon resale
Payback Period	10-15 years	Based on savings and value

Final Thoughts

Bay window costs in 2025 range from £1,200 for a small uPVC setup to £4,000 for a large timber or aluminium design. Size, material, and installation extras shape the price, but the added space, light, and value make them a worthy investment. Seek three quotes from FENSA-registered installers to secure the best deal—bay windows are a blend of beauty and practicality for any UK home.