Secondary Glazing Cost by Window Size

    Accurate pricing for every window dimension in your home

    7 min read

    Window size is the primary cost factor for secondary glazing. Larger windows require more material and labour, significantly impacting the final price. This guide provides detailed pricing for all common window sizes.

    Quick Reference Chart

    SizeAreaAcrylic4mm Glass6mm Glass
    Small Window0.54 m²£80-£135£110-£190£135-£215
    Standard Window1.08 m²£160-£270£215-£380£270-£430
    Large Window1.80 m²£270-£450£360-£630£450-£720
    Patio Door3.78 m²£565-£945£755-£1,320£945-£1,510
    Bay Window (3-panel)4.50 m²£675-£1,125£900-£1,575£1,125-£1,800

    * Prices exclude installation. Add installation costs shown in detailed breakdown below.

    Detailed Size Breakdown

    Small Window0.54 m²

    600mm x 900mm

    Typical location: Small bathroom, toilet

    Acrylic

    £80-£135

    4mm Glass

    £110-£190

    6mm Glass

    £135-£215

    Installation: £50-£80 per window

    Total installed cost: £160 - £295

    Standard Window1.08 m²

    900mm x 1200mm

    Typical location: Bedroom, kitchen

    Acrylic

    £160-£270

    4mm Glass

    £215-£380

    6mm Glass

    £270-£430

    Installation: £80-£120 per window

    Total installed cost: £295 - £550

    Large Window1.80 m²

    1200mm x 1500mm

    Typical location: Living room, dining room

    Acrylic

    £270-£450

    4mm Glass

    £360-£630

    6mm Glass

    £450-£720

    Installation: £120-£180 per window

    Total installed cost: £480 - £900

    Patio Door3.78 m²

    1800mm x 2100mm

    Typical location: Garden access

    Acrylic

    £565-£945

    4mm Glass

    £755-£1,320

    6mm Glass

    £945-£1,510

    Installation: £200-£300 per window

    Total installed cost: £955 - £301

    Bay Window (3-panel)4.50 m²

    3000mm x 1500mm

    Typical location: Traditional living rooms

    Acrylic

    £675-£1,125

    4mm Glass

    £900-£1,575

    6mm Glass

    £1,125-£1,800

    Installation: £300-£450 per window

    Total installed cost: £1200 - £451

    Non-Standard Shapes & Sizes

    Complex window shapes require custom manufacturing and installation, adding premium costs to standard pricing.

    Arched Top Window

    +20-30%

    Custom curved glazing required

    Example: Standard £300 window becomes £360-£390

    Circular/Oval Window

    +30-40%

    Specialist manufacturing needed

    Example: Standard £300 window becomes £390-£420

    Triangular Window

    +25-35%

    Custom frame angles

    Example: Standard £300 window becomes £375-£405

    Bay Window (4+ panels)

    +40-50%

    Complex multi-panel system

    Example: 3-panel £1,200 becomes £1,680-£1,800

    Cost-Saving Tips by Size

    Small Windows Strategy

    • Consider DIY for small bathrooms and toilets

    • Magnetic systems ideal for £80-£150 range

    • Bundle multiple small windows for bulk discount

    • Acrylic performs well at this size

    Large Windows Strategy

    • Always use professional installation for safety

    • 6mm glass justified for acoustic performance

    • Sliding systems more cost-effective than hinged

    • Consider phasing if budget limited

    How to Measure Your Windows

    1. Measure the Window Opening

    Measure width and height of the reveal (recess) in millimetres. Take measurements at top, middle, and bottom for width; left, center, and right for height.

    2. Use the Smallest Measurement

    Windows are rarely perfectly square. Always use the smallest width and smallest height measurement to ensure the secondary glazing fits.

    3. Calculate Area

    Multiply width x height (in metres) to get square metres. Example: 1.2m x 1.5m = 1.8m². This determines material cost.

    4. Account for Shape

    For non-rectangular windows, calculate as if they were rectangular (use maximum dimensions) and add the shape premium (20-40%).