These are broad budgeting figures rather than fixed prices. Current UK guides place aluminium sash windows at approximately £800 to £1,500 each and aluminium bay windows at around £2,500 to £4,500 supplied and fitted.

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Aluminium Casement Window Costs

 

Casement windows are one of the most common aluminium window styles. They are hinged at the side or top and can be manufactured with fixed panes, opening sections or a combination of both.

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A standard aluminium casement window will generally cost between £500 and £1,050 supplied and fitted. Smaller fixed windows may cost less, while large windows with several opening sections can reach £1,200 to £1,600 or more.

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The number of opening sections matters because each opener requires hinges, handles, locks, seals and additional manufacturing work. A large fixed pane may therefore cost less than a smaller window divided into several opening lights.

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Aluminium Sash Window Costs

 

Aluminium sash windows recreate the vertical proportions of traditional sliding sash windows while using modern aluminium frames and double glazing.

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A typical aluminium sash window may cost approximately £800 to £1,500, although bespoke heritage-style windows, unusually large openings and specialist glazing can cost more.

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Aluminium sash windows may suit contemporary homes and some replacement projects, but careful consideration is required in conservation areas or period properties where timber windows may be expected.

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Aluminium Bay Window Costs

 

Bay windows cost more because they are formed from several window units connected at different angles.

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A replacement aluminium bay window may cost between approximately £2,500 and £4,500, depending on:

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• The number of window sections

• The width and height of the bay

• The number of opening windows

• Structural support requirements

• The condition of the existing bay roof

• Internal and external finishing work

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The installer may also need to provide structural bay poles or temporary support while the existing frames are removed.

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Where a new bay is being created in a flat wall, the cost will be substantially higher because foundations, brickwork, roofing, structural work and internal alterations may be required.

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Aluminium Window Costs for a Whole House

 

Replacing the windows throughout a typical three-bedroom property with aluminium frames may cost approximately £7,000 to £16,000.

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A straightforward house with eight to ten standard windows may fall towards the lower end of this range. A larger property with bays, feature glazing, French doors or unusually large windows will cost more.

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Current 2026 cost guides place a typical eight-to-ten-window aluminium replacement project at around £7,000 to £10,000, while higher-specification systems may increase the total to between £8,000 and £16,000.

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Homeowners replacing several windows at the same time may receive a better overall rate than someone ordering a single bespoke window because surveying, delivery and installation costs can be shared across the project.

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Aluminium Window Cost Per Square Metre

 

Some suppliers calculate aluminium window prices partly by size. A broad guide is approximately £550 per square metre, although this method should only be used for preliminary budgeting.

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Two windows with the same overall area can have very different prices. A fixed pane will normally be simpler than a window containing several openers, mullions, transoms and locking mechanisms.

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The final quotation should therefore be based on the complete window design rather than the area of glass alone.

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Are Aluminium Windows More Expensive Than UPVC?

 

Aluminium windows usually cost more than UPVC windows. One current UK cost guide places an average aluminium window at around £475 compared with approximately £325 for UPVC, although actual fitted quotations can be much higher for both materials.

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The additional cost reflects the manufacturing process, powder-coated finish and the ability to create slimmer but structurally strong frames.

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Aluminium may offer better value where the design calls for:

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• Slimmer window frames

• Larger glass panels

• Wide or tall openings

• Contemporary architecture

• Matching aluminium doors

• Dark-coloured frames

• Minimal maintenance

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UPVC will generally remain the more economical choice where keeping the initial replacement cost as low as possible is the main priority.

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What Affects Aluminium Window Prices?

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Window Size

Larger windows require more aluminium and glass. Large glazed units may also need thicker glass, specialist lifting equipment or additional installers.

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Number of Opening Sections

Fixed glazing is normally less expensive than opening windows. Each opening section adds hardware, locking systems and manufacturing time.

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Window Style

Standard casement windows are generally among the least expensive options. Sash windows, tilt-and-turn windows, bays, shaped windows and bespoke feature glazing cost more.

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Frame Colour

Aluminium windows are normally powder coated. Standard colours such as white, black and anthracite grey may be included within the basic range.

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Less common colours, textured finishes and different colours internally and externally can increase the price.

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Glazing Specification

Standard double glazing is normally the entry-level specification. The quotation will increase when the windows include:

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• Triple glazing

• Acoustic glass

• Laminated security glass

• Solar-control glass

• Toughened safety glass

• Decorative or obscure glazing

• Integral glazing bars

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Large south- or west-facing windows may also require consideration of solar gain and summer overheating rather than thermal performance alone.

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Thermal Performance

Modern aluminium windows normally contain a thermal break separating the internal and external parts of the frame.

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Higher-performance frames, warm-edge spacer bars, low-emissivity glass and gas-filled units may increase the initial price but can improve the overall thermal performance of the window.

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Installation and Access

Ground-floor windows with straightforward access will normally be less expensive to replace than windows requiring scaffolding, lifting equipment or work above a conservatory or extension roof.

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London and other high-cost areas may also attract higher installation charges.

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Removal and Making Good

A quotation may or may not include:

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• Removal of the existing windows

• Disposal charges

• Internal trims and window boards

• Plaster repairs

• External sealants

• Render or brickwork repairs

• Redecoration

• Scaffolding

• Building-control certification

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These items should be confirmed before comparing the final prices.

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Black and Anthracite Aluminium Window Costs

 

Black and anthracite grey are popular aluminium window colours because they complement contemporary extensions, modernised houses and aluminium bifold or sliding doors.

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Standard black or anthracite finishes may be available without a substantial premium. However, bespoke colours, metallic finishes and dual-colour frames will normally cost more.

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For example, a homeowner might choose anthracite grey externally to match the roof and white internally to suit the room. This requires a dual-colour manufacturing process and is likely to increase the quotation.

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Double or Triple-Glazed Aluminium Windows

 

Most replacement aluminium windows are supplied with double glazing. Triple glazing is available but will increase the cost and weight of each unit.

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Triple glazing may be worthwhile where the property is exposed to cold weather or the windows form part of a carefully designed energy-efficiency upgrade. However, it is not automatically the best choice for every property.

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The frame, installation quality, airtightness and surrounding wall construction are also important. An expensive glazed unit will not perform properly when the frame has been poorly fitted or the perimeter has not been adequately insulated and sealed.

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Do Aluminium Windows Need Planning Permission?

 

Replacing windows with a similar design does not normally require a planning application for an ordinary house, but restrictions can apply to:

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• Listed buildings

• Flats and maisonettes

• Conservation areas

• Properties affected by an Article 4 direction

• Windows being enlarged or repositioned

• Significant changes to the external appearance

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Changing traditional timber windows to dark aluminium frames may materially alter the character of a period property.

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Homeowners should establish whether permission or listed building consent is required before ordering the windows. Bespoke aluminium windows cannot usually be altered easily once they have been manufactured.

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Comparing Aluminium Window Quotations

 

Prices should be compared on a like-for-like basis. The lowest quotation may be based on a different frame system, glazing specification or installation allowance.

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Ask each installer to confirm:

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• The frame manufacturer and product range

• The colour and powder-coated finish

• The glass specification

• Window energy or thermal performance

• The number of opening sections

• Handles and locking systems

• Trickle-ventilation arrangements

• Removal and disposal of existing frames

• Internal and external making good

• Whether VAT is included

• Product and installation guarantees

• Certification following installation

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It is also sensible to examine examples of completed aluminium window installations rather than relying on brochures or small product samples alone.

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Are Aluminium Windows Worth the Cost?

 

Aluminium windows can be a worthwhile investment where slim sightlines, larger areas of glass and a contemporary appearance are important.

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They are particularly effective for modern extensions, architectural renovations and properties using aluminium bifold or sliding doors.

Using the same frame colour and profile across the project can create a coordinated appearance.

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However, the best material will depend on the property, available budget and architectural style. Aluminium may not always be appropriate for a listed building or a traditional elevation where timber detailing is an important feature.

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Find Trusted Aluminium Window Installers

 

The cost of aluminium windows depends on their size, style, glazing specification and the complexity of the installation. A detailed survey is the best way to obtain an accurate quotation for your property.

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APN Double Glazing can connect homeowners with experienced local aluminium window installers for individual replacement windows, whole-house upgrades and larger renovation projects.

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Get in touch for expert advice and a free, no-obligation quote.