APX Flush Casement.
Slim, thermally broken aluminium that opens as a classic casement or a British-style projecting window. U-values from 0.9 W/m²K, made to your exact opening.
APX Flush Casement Window
Aluminium Window System
Glazing
Up to 44mm
U-Value (W/m²K)
From 0.9
Security
PAS 24
Frame
Any RAL
Hardware
6 Finishes
Warranty
10 Year
One System. Two Ways to Open.
APX Casement is a thermally broken aluminium window with a 32mm polyamide barrier at its core. Every sash opens outward, as a classic side-hung casement or a top-hung projecting window, so you choose the action room by room. Slim aluminium sightlines carry more glass than uPVC or timber, and the whole system is engineered and weather-tested for the UK.
Engineered for everyday excellence.
Made to measure for London homes. Slim aluminium frames around serious engineering, and four good reasons it earns its place on your home.
Two ways to open
Side-hung casement or top-hung projecting from one system. Choose the opening action per room, with the same slim frame throughout the house.
Seriously insulated
A 32mm polyamide thermal break splits the aluminium, achieving U-values from 0.9 W/m²K and acoustic insulation up to 45dB.
Built for British weather
Class 4 air permeability, E1200 watertightness and CE2400 wind resistance ratings. Tested well beyond what a London winter throws at it.
Strong, slim, any colour
1.6mm aluminium walls carry big glass on slim frames, powder-coated in any RAL colour with dual-colour options inside and out.
Specifications
0.9
U-Value (W/m²K)
Whole-window U-values from 0.9 W/m²K thanks to the 32mm thermal break.
PAS 24
Security
Tested and certified to PAS 24 for enhanced protection and peace of mind.
45 dB
Acoustic Rating
Sound insulation up to Rw 45 dB with acoustic glazing options.
Up to 44mm
Glazing
Glazed units from 23mm to 44mm, double or triple glazed.
Multi-point
Locking
Advanced multi-point locking for superior security.
100%
Recyclable Aluminium
Sustainable by design. Aluminium is fully recyclable, again and again.
10 Years
Guarantee
Backed by our 10-year manufacturing guarantee.
Any RAL
Colours
Powder-coated in any RAL colour, with dual-colour options.
Technical
Built for performance
Thermally broken 70mm aluminium frame and sash joined by a 32mm polyamide bar, with 1.6mm profile walls. Takes glazed units from 23mm to 44mm and is PAS 24 certified. Heavy-duty sashes go up to 1800 x 1800mm and 100kg, backed by a 10‑year manufacturer guarantee.
Configurations
Flexible design options
Side-hung casement, top-hung projecting and fixed lights, all from one system. Reduced or heavy-duty sash options cover everything from compact openings to 1800 x 1800mm panels.
Finishes
Made to match your space
Powder-coated in any RAL colour, in matt, gloss or textured finishes that never need repainting. Dual-colour options let you run a different shade inside and out. All finishes carry the same 10-year guarantee.
Make it yours.
Selected colour · Agate Grey
How long does installation take?
Most window installs are completed in 1-2 days. Doors typically take 1-3 days depending on threshold work. Full-house or multi-room replacements run 3-7 days. We give you a precise schedule at the survey stage so you can plan around it, no open-ended jobs.
Is the installation FENSA-registered, and do I get the certificate?
Yes. Apex Glazing is FENSA-registered (Reg 40373). On completion you receive a FENSA certificate, which satisfies Building Regulations Part L compliance and removes the need for separate council approval. Certificates are issued within 30 days and stored in your FENSA online account for future house sales.
What warranty do I get?
10-year manufacturer warranty on the product itself (frame, glass seal, hardware) plus a 12-month workmanship guarantee from us on the installation. We've been trading since 2005 with 6,340 completed projects and a 5.0-star Google rating, we'll come back if anything's not right.
Do you remove and dispose of the old windows or doors?
Yes, removal of existing units, safe disposal at a licensed waste facility, making good of internal and external reveals, and a thorough final clean-up are all included in the quoted price. There are no extras for skip hire, scaffolding, or waste removal.
Can you match existing windows for a phased replacement?
Yes. We can RAL colour-match the new frames to your existing units, replicate sightlines, glazing bar layouts, and hardware style to keep a phased replacement consistent. Bring photos to the survey, or we'll come and measure the existing windows so the new ones blend in seamlessly when fitted alongside.
