How Much Do Aluminium Windows Cost?
Updated: 12 hours ago
A standard aluminium casement window typically costs £450 to £800 supplied and fitted, a slim-frame or steel-look window £900 to £2,800, and a three-bedroom house of ten windows £6,000 to £12,000 in standard aluminium, all including VAT. The price of each window is set by its size, opening type, frame system, glass and finish, in roughly that order.
We make aluminium windows and doors to measure, in modern slim-frame and steel-look ranges, and every quote follows a survey of the actual openings.
Typical UK prices
Supplied and fitted, including VAT:
Standard aluminium casement, around 1.2m x 1.2m: £450 to £800.
Tilt-and-turn window: £500 to £800.
Three-section bay window: £1,500 to £2,500.
Slim-frame or steel-look aluminium window: £900 to £2,800.
Whole house, ten windows: £6,000 to £12,000 in standard aluminium; £10,000 to £25,000 or more in steel-look.
Slim-frame and steel-look systems, including ours, sit toward the upper end of these ranges. These are typical UK market prices from published cost guides as of 2026; bespoke designs are priced after a survey.
What does an aluminium window cost per window?
A standard aluminium casement window of average size, around 1.2m x 1.2m with one opening light, is the starting point for pricing. This is a thermally broken frame with double glazing in a standard colour, supplied and fitted.
A slim-frame aluminium window of the same size, where the profile is narrower and the glass area larger, costs more. The frame does more with less material and the engineering behind that is the difference.
A steel-look aluminium window, with the narrow glazing bars and the proportions of an old steel-framed window but the performance of modern aluminium, sits at the top of the range. These suit renovation and conservation projects, and the glazing bars add to the cost.
Larger windows, windows with more opening lights, and shaped or arched windows all rise from there. Fixed windows with no opening light cost less than opening ones of the same size.
What do aluminium windows cost for a whole house?
For a typical house with ten to twelve windows of mixed sizes, replacement in slim aluminium is quoted as a single project, supplied and fitted. Steel-look windows across a whole house are more, and a house with large picture windows or a glazed gable is priced on the glass area rather than the count.
Whole-house pricing benefits from scale: one survey, one delivery, one installation team on site for a week rather than four separate visits. It is also where colour and design consistency matter most, because every window is seen against every other.
Matching the windows to the doors is the other reason to think whole-house. Our guide to bifold doors cost covers the doors; the windows should be the same system, the same colour and the same sightlines, or the elevation looks assembled rather than designed.
What changes aluminium window prices?
Frame system comes first. Standard, slim-frame and steel-look are three different products at three price points. All should be thermally broken; an unbroken aluminium frame is cold and belongs to a previous generation.
Size and configuration come second. Glass area drives cost. Opening lights cost more than fixed. Tilt-and-turn, top-hung and side-hung casements are priced differently.
Glass comes third. Double glazing is standard. Triple glazing improves winter performance and adds weight. Solar control coatings help on south and west elevations. Acoustic glass for a road-facing window and laminated glass for security are further options.
Colour and finish come fourth. A standard colour is included. Dual colour, with a different finish inside and out, is an upgrade we specify often. Textured and metallic finishes add.
Hardware comes fifth: handles, trickle vents, restrictors and locks in a matching finish.
Installation is last. Fitting into an existing opening with the old window removed is part of a standard supply-and-fit quote. Enlarging openings, new lintels, internal plastering and external making-good are extra.
Aluminium vs timber vs standard windows on cost
Timber windows and aluminium windows are the two materials a period house or a house of any architectural quality should be choosing between, and on price they are closer than most people expect. A well-made painted hardwood window costs about the same as a slim aluminium one of the same size, and more once the decorating over its life is counted. Aluminium is finished once; timber is finished every few years. Standard frames cost less than either per unit, but the profiles are deeper, so the glass area is smaller and the window more visible, and the colour range is narrower.
The choice is about the look and the building. On a listed house or in a conservation area the planning authority may require timber, and timber is right for a house where the windows were always timber. On a modern house, an extension or a renovation where the glazed doors are aluminium, aluminium windows in the same system and colour are the consistent answer. Steel-look aluminium bridges the two, giving a period proportion with modern performance; our guide to heritage aluminium windows covers the range.
How long do aluminium windows last?
A well-made thermally broken aluminium window has a service life of decades, and the powder-coated finish does not need repainting. That changes the comparison over time: a window that costs more to buy but needs no decorating and outlasts a cheaper frame often costs less per year of use. The parts that wear are handles, hinges and seals, and they are replaceable without changing the window.
Fitting is quick once the windows are made. A whole house is usually a week or so on site for one installation team, with each opening out and back in on the same day.
How to keep aluminium windows cost down
Specify the whole house at once rather than in phases: one survey, one order, one installation.
Keep opening lights to where they are needed; a large fixed pane with one opener beside it is often better than two openers.
Choose a standard colour unless dual colour matters to the room.
Decide the glass by elevation: solar control on the south and west, standard insulated units on the north, acoustic glass only on the road side.
Match the doors and windows in one system, because a mixed elevation costs more to correct than to avoid.
What should an aluminium window quote include?
A window quote should list every opening with its size, its configuration and which lights open, and then the system, the glass specification, the colour, the hardware and the trickle vents. It should cover survey, manufacture, delivery, installation, removal of the old windows, sealing and the internal and external making-good, and it should say whether VAT is included.
The item most often missing is the making-good. Replacing a window disturbs the plaster inside and the render or brickwork outside, and a quote that stops at "fitted" leaves the decorating to you. The other item to look for is the certification: a replacement window must meet building regulations for thermal performance and safety glazing, and an installer registered with a competent person scheme self-certifies the work, which is what a buyer's solicitor will ask for when the house is sold.
Aluminium windows cost questions, answered
How much is an aluminium window supplied and fitted?
Typically £450 to £800 for a standard casement of average size and £900 to £2,800 for a slim-frame or steel-look window, including VAT. Within that, the price is set by size, opening lights, glass and finish. Removal of the old window, fitting and making good are included in a supply-and-fit price; a new or enlarged opening is extra. We price each window after surveying the opening.
Why are aluminium windows more expensive?
The material, the engineering of a thermally broken slim profile, and the fact that every window is made to measure. The result is a narrower frame, more glass and a longer life than the alternatives.
Are aluminium windows cold?
Modern thermally broken aluminium windows are not. The reputation belongs to older unbroken frames. With good glazing an aluminium window meets the same thermal standards as any other.
Do new windows need planning permission?
Replacing windows in an existing opening does not, except on a listed building or where an Article 4 direction applies in a conservation area. New windows must meet building regulations for thermal performance and safety glazing, and a certified installer self-certifies this.
Talk to our design team
If you would like to talk to us about your project, we survey every opening and quote the house as a whole.
