Standard casement
A clean all-round replacement style with balanced sightlines and broad suitability across contemporary and mixed-style properties.
- 75mm sightline
- Best all-round route for most homes
- Flat, chamfered, or ovolo styling options
Specification-led page
Aluminium Casement Windows
This page stays intentionally lean on imagery where product-accurate photography is still being expanded. The configuration, threshold, hardware, and brochure guidance below reflect the current product brief without borrowing mismatched visuals.
Windows
Aluminium Casement Windows
Slimline aluminium casement windows with clean sightlines, strong security, and flexible styling for contemporary or traditional homes.
- ALUK 58BW aluminium casement system
- Sightlines from 66mm (heritage) to 75mm (standard)
- U-value 1.4 W/m²K (double) or 1.2 W/m²K (triple)
- Green Guide A rated — PAS 24 and Secured by Design
10YEARGUARANTEE
Assure certifiedNo subcontractorsFinance availablePersonalise Your Window
Colours & Finishes
Frame Colour: Anthracite Grey
Standard colours
Dual colour available, different interior and exterior finishes on request.
Hardware Finish: Black
Handles, letterplates, and accessories available in matching finishes.
Made to measure. Confirm your colour and hardware choice during your free survey.
Design Choices
Choose profile and security specification
Compare style routes and opening/security setups for aluminium casement projects. Final specification is confirmed during survey.
Made to measure
Three profile routes with different sightline character
Standard, flush, and heritage all sit on the aluminium casement platform, so you can tune the final look without changing product family.
Flush casement
The sash sits level with the frame face for a tighter, premium finish where detailing matters more than a standard projected sash.
- Flush external finish
- Premium appearance on refurbishments
- Strong fit for design-led upgrades
Heritage steel look
A slimmer route intended to replicate traditional steel-style window proportions with sharper vertical lines and lighter frame presence.
- 66mm sightline
- Steel-look styling for period-industrial schemes
- Compatible with slim bar layouts
Opening formats and security options in one platform
Mix vent formats around the house while keeping a consistent frame family, then choose security and glazing packages to suit each elevation.
Opening configurations
Top-hung, side-hung, tilt-before-turn, fixed lights, bays, and coupled frames can all be specified from the same system.
- Top and side hung vents
- Tilt-before-turn option
- Bay and coupled frame assemblies
Security specification
Specify PAS 24 and Secured by Design packages with robust locking hardware for projects where tested security is a key requirement.
- PAS 24 option
- Secured by Design option
- Multi-point locking hardware
Glazing performance tuning
Glazing build-ups from 24mm to 40mm allow thermal, acoustic, and solar-control priorities to be tuned by room orientation and use.
- 1.4 W/m2K double glazing route
- 1.2 W/m2K triple glazing route
- Acoustic glazing options up to 44 dB
Free Survey
Ready to shortlist this product properly?
If this looks like the right fit, we can survey the opening, confirm the specification, and price it properly for your home with no obligation.
Free surveyFixed quoteDirect CII installation team
These aluminium casement windows are built for projects where slimmer sightlines, a broader powder-coated colour palette, and a sharper architectural finish matter. They suit modern extensions, full-house replacements, and larger glazed openings where standard frames can feel visually heavy. CII surveys, supplies, and installs the full package across Essex with our own team from first measure to final sign-off.
Key Specifications
Secured by Design and PAS 24 options available for higher-security specifications
Class 4 air permeability and 9A water tightness on the tested platform
Internally or externally beaded configurations depending on design requirement
Green Guide A rated aluminium system with slim contemporary sightlines
Single and dual-colour powder coating across the RAL range
Installed by CII's directly employed team with survey, fitting, and sign-off handled in house
Core Information
Key information for Aluminium Casement Windows
The main performance, specification, and installation details that shape how this aluminium range works in practice.
Best For
Where this range fits best
Contemporary homes with larger glazed openings
Homeowners replacing ageing aluminium or timber frames
Projects needing a broader RAL colour palette than standard UPVC ranges
Energy efficiency
Thermally broken aluminium framing with polyamide thermal breaks and glazing options from 24mm to 40mm keeps this range strong on performance as well as appearance. Whole-window U-values can reach 1.4 W/m2K, dropping to 1.2 W/m2K with triple glazing, making these windows a strong fit for modern refurbishments and extension work.
Security
This aluminium casement range can be specified to Secured by Design and PAS 24 standards, with robust locking hardware and rigid aluminium sections that remain controlled even on larger vents. That matters when you want slim sightlines without compromising day-to-day security or weather performance.
Colours and specification
Aluminium opens up a much broader powder-coated finish range than a standard replacement window. Popular choices such as anthracite grey, black, and white remain available, but the real flexibility comes from bespoke RAL colours and dual-colour inside/outside combinations. Profile styling can also be tuned between flat contemporary, chamfered, or ovolo detailing depending on whether the project is modern or more traditional.
Installation and guarantee
All aluminium casement installations are covered by CII's 10-year installation guarantee and signed off on completion with Assure certification where applicable.
System Benefits
Performance Benefits Beyond Style Choices
After the design specification is set, these are the technical and delivery strengths that matter most in day-to-day use.
Weather-tested platform
The tested aluminium system targets Class 4 air permeability and 9A water tightness to support reliable weather performance on exposed elevations.
Thermally broken frame engineering
Polyamide thermal break technology and deeper glazing build-ups help deliver strong thermal outcomes while retaining slimline aluminium proportions.
Durable powder-coated finish
Factory-applied powder coating is designed for long-term colour stability with low ongoing maintenance compared with painted timber systems.
Survey-led installation by CII
Specification, fitting, and sign-off are handled by CII's directly employed team so build quality is controlled from first measure to final handover.
How It Works
From Survey to Sign-off
Step 1
Survey
We visit, measure, and advise on the right configuration for your property.
Step 2
Install
Our directly employed team installs with clean, tidy workmanship.
Step 3
Sign-off
Final checks, handover, and Assure certification where required.
Next Step
Want a fixed quote from a real survey?
We will measure up, talk through finishes and installation details, and give you a clear quote based on the actual opening rather than a generic estimate.
Free surveyFixed quoteDirect CII installation team
Checkatrade
“Fantastic experience from initial survey to completion. The team were professional, tidy, and the attention to detail on the finish was fantastic. Couldn't be happier with our new windows.”
Checkatrade
“Used CII for our entire house of windows. Brilliant from start to finish. Knowledgeable, reliable, and very professional. The quality of the product and installation is second to none.”
Questions Answered
