UK cost guide · Updated 30 Sep 2026
Bay and Bow Window Prices
Bay and bow windows cost considerably more than a flat casement because they use several frames and a projecting structure. The current model places common fitted centres at roughly £1,850 for three sections, £2,350 for four and £2,850 for five.
Current fitted examples
These figures use the same pricing model as the main calculator. They are market benchmarks for quote checking, not binding installer quotations.
Bay versus bow: why quotes differ
A bay normally uses fewer, more angular sections, while a bow creates a softer curve using several narrower frames. The exact structure, roof/cill work and whether the existing projection can be reused can all matter more than the headline number of sections.
That is why the comparison is best used as a fitted market range rather than a fixed tariff.
What to line up before comparing quotes
- Number of sections and overall width
- Whether the existing base, roof and cill are retained
- Opening sections within the bay or bow
- Frame material, colour and glazing specification
- Any structural or making-good work outside a normal replacement
What “fitted” means here: supply, standard replacement installation and ordinary 20% VAT are included. Structural alterations, scaffolding, difficult access and highly bespoke work can sit outside the standard estimate.
Related price guides
Use these pages to compare the nearest specifications before building your own estimate.
Questions people ask
Direct answers to the search questions behind this guide.
How much is a three-section bay window?
The current fitted centre is about £1,850 for a standard three-section replacement example.
Is a bow window always more expensive than a bay?
Not always, but bows often use more sections and can involve more complex projecting work, so specification matters.
Are structural repairs included in these prices?
No. The benchmark assumes standard replacement work; significant structural repairs or rebuilding the projection can add separate costs.
Price the actual project.
Choose the product, rough or exact size, layout, glazing, colour and region. The personalised result is a one-off £2.99.
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