“Ordered slim-profile aluminium casement windows for the whole house. The product quality is incredible — so much more light and the house looks completely modernised. Very competitive pricing too.”
James T. — Harrogate
Aluminium Casement Windows in Leeds
Premium aluminium casement windows — also called slimline aluminium windows or thermally broken windows — supplied across Leeds and West Yorkshire from £400 per window. Slim 60mm profiles, robust espagnolette locking, side hung, top hung and fixed light configurations, A-rated thermal performance, and frames up to 3,000 × 2,200mm. Made to measure at our Beeston (LS11) workshop with free local delivery, 2–10 day lead times, and a 10-year guarantee.
Lead Time
2–10 Working Days
Max Frame Size
3,000 × 2,200mm
U-Value
From 1.4 W/m²K
Glazing Range
28–44mm
Local Leeds specialistsInstaller introductions availablePremium aluminium systemsEspagnolette locking
Why Choose Our Casement Windows?
Our aluminium casement windows — also called slimline aluminium windows, thermally broken windows, or aluminium replacement windows — are made to measure at our Beeston (LS11) workshop, supplying homeowners across Leeds, Bradford, Wakefield, Halifax, Harrogate and the wider West Yorkshire region. Slim 60mm profiles, A-rated thermal performance, robust espagnolette locking, and a 10-year guarantee on every window. Whether it's a full-house replacement on a 1930s semi in Horsforth, a feature picture window for a Roundhay extension, or matching new units for a stone-built terrace in Bradford or Halifax, every window is precision-cut, assembled and quality-checked before dispatch. Need an installer? We can recommend trusted local fitters.
Slim Sightlines
Clean aluminium profiles for a modern, minimal aesthetic with maximum glass area.
Versatile Sash Options
Side hung, top hung and fixed light configurations to suit any opening.
Thermal Performance
Thermally broken profiles with U-values from 1.4 W/m²K exceeding Building Regs.
Large Frame Sizes
Frames up to 3,000 × 2,200mm for generous openings and maximum light.
Casement Windows Configurations
Combine side hung, top hung and fixed light sashes in any arrangement. Every window is custom-built to your exact measurements. Friction stays and espagnolette locking on all opening sashes.
Side Hung
Opens left or right on vertical hinges. The most popular type for living rooms, bedrooms and dining areas.
Max Width
1,200mm
Max Panel Height
1,500mm
Max Panel Width
1,200mm
All configurations custom-made to order · Low-threshold options available
7 Stock Colours + Any RAL
Choose from our seven stock colours with the fastest lead times, or specify any RAL colour for a bespoke finish. Dual-colour options — different inside and out — are available at no extra charge on all stock finishes.
White
Agate Grey
Anthracite Grey
Black
Agate Grey on White
Grey on White
Black on White
RAL
Any RAL Colour
Woodgrain Finish
2–5 working days
Stock colours (unglazed)
6–10 working days
Stock colours (glazed)
~2 weeks
RAL colours
3–5 weeks
Woodgrain finishes
Dual-colour (e.g. Anthracite outside / White inside) available on all stock finishes at no extra cost.
Engineered for Energy Efficiency
Our casement windows feature thermally broken aluminium profiles with polyamide thermal break technology, exceeding current Building Regulations.
1.4
W/m²K U-value (double)
1.0
W/m²K U-value (triple)
Class 4
Air permeability
28–44mm
Glazing unit range
Exceeds Part L
Our U-values comfortably exceed the Building Regulations Part L requirement of 1.6 W/m²K.
Part L — Thermal performancePart A — Structural integrityPart F — Ventilation compliance
Built to Keep You Safe
Multi-point locking, internally beaded glazing, and anti-lift protection come as standard on every product we supply.
Espagnolette Locking
Multi-point espagnolette locking system engages at multiple points along the sash for robust resistance.
Internally Beaded
Glazing beads sit inside the property — glass cannot be removed from the outside.
Hinge-Side Keeps
Hinge-side security keeps on all side hung sashes prevent the hinge edge being forced open.
Secured by Design
SBD-accredited hardware packages available on request for enhanced certification.
Peace of Mind
Espagnolette multi-point lockingInternally beaded glazingHinge-side security keepsSBD accreditation available
Hardware & Add-ons
Customise your casement windows with premium hardware options and practical add-ons.
Handle Finishes
Available in White, Black, Anthracite Grey and Chrome to complement your window colour.
Friction Stays
High-quality friction stays on all opening sashes for smooth, controlled operation.
Trickle Vents
Background ventilation for Part F compliance without compromising security.
Georgian Bars
Internal, external or duplex Georgian bar options for a traditional glazing pattern.
Cill Options
Cills available in 90mm, 150mm, 180mm, 230mm and 250mm depths with head extensions.
Specifications
Everything you need to know about colours, sizes, and performance.
Window Sizes
- Max sash: 1,200mm × 1,500mm (opening sashes)
- Max frame: 3,000mm × 2,200mm
- Side hung, top hung, fixed and combination layouts
Cill & Head Options
- Cills in 90mm, 150mm, 180mm, 230mm and 250mm
- Head extensions in 20mm and 38mm
Lead Times
Fast, reliable delivery with guaranteed dates that won't change.
2–5
Working days
Unglazed
Standard Colours (Subject to Order Quantity)
6–10
Working days
Glazed
Standard Colours (Subject to Order Quantity)
2
Weeks
RAL Colours
4–6
Weeks
Woodgrain Colours
Frequently Asked Questions
Aluminium window prices start from around £400 per window (supply only) for a standard casement. Typical total project cost including installation (installer arranged separately) is £600–£1,200+ per window depending on size, style, and glazing.
What customers say about our Casement Windows
5.0 from 1 verified review
We Deliver Casement Windows Across Yorkshire
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