Schüco Aluminium Windows: AWS System Overview

Schüco's AWS window range is one of the most widely used aluminium window families in UK residential work. If you are replacing windows across a whole house, or specifying for a new extension in Borehamwood, understanding the AWS family in outline will help you make sense of quotations and hold a useful conversation with your fabricator. This overview covers the residential systems most likely to appear on your project.

What "AWS" means and how the numbers work

AWS stands for Aluminium Window System. The number that follows is the frame depth in millimetres. The "SI+" suffix denotes the current Super-Insulated generation with an improved thermal break. A higher number generally means better thermal performance and greater flexibility on glazing spec, at some cost in profile depth.

The core residential range

• AWS 75.SI+ — 75 mm depth, the workhorse of the range. Suits most domestic replacement work. Handles double and triple glazing up to a reasonable weight.
• AWS 90.SI+ — 90 mm depth, higher thermal performance, better fit for Passivhaus and low-energy standards.
• AWS 65.HI — 65 mm depth, entry point of the range where extreme thermal spec is not required. Slimmer sightlines can be achieved.

The variation matters because on a typical residential façade, the sightline (how much frame is visible from outside) and the glass-to-frame ratio are aesthetic decisions as much as thermal ones. AWS 75.SI+ is a compromise that suits most jobs; if you are pushing for Passivhaus performance, AWS 90.SI+ is the honest answer.

Opening types

All the current AWS profiles support the standard residential opening types: fixed lights, side-hung casements, top-hung casements, tilt-and-turn, and fully reversible. Tilt-and-turn is the classic European detail and popular on flats where cleaning outside surfaces from inside is important. Side-hung casement remains the UK residential default and is the most cost-effective option for straightforward window replacement.

Where AWS windows sit against alternatives

The direct comparisons are usually against Cortizo aluminium windows, Reynaers systems, or against composite windows like Velfac's composite range, which combines an aluminium exterior with a timber interior. Composite systems can win on thermal spec and interior aesthetic; full-aluminium systems like AWS remain cheaper, lighter and more resilient over time — the choice is genuinely about priorities, not technical superiority in one direction.

Getting the specification right

Two decisions dominate the aluminium window specification conversation:

1. Depth (75 vs 90): AWS 75.SI+ meets Part L on most retrofits comfortably. Move to AWS 90.SI+ if you are pursuing new-build thermal standards or fitting to a passive-standard extension.
2. Glazing: Standard argon-filled double glazing is the default. Triple glazing is worth costing on north-facing elevations and for acoustic reasons on busier roads.

The other decisions — colour, ironmongery, restrictor spec, trickle vents — are relatively fixed by regulation or aesthetic and are less consequential to overall performance.

Installer selection in Borehamwood

Aluminium windows are a system product, and system products depend on fabrication accuracy. Local fabricators approved for Schüco supply — 5EC being one — carry the training and the shop-drawing capability to produce and install the range without generic workarounds. Their published information on aluminium window systems is a useful sanity check on what a proper aluminium window job should include.

Aftercare

Aluminium windows need very little. Wipe the frames occasionally, lubricate the hinges and locking gear yearly, and keep the drainage slots at the base of the frame clear. Powder-coated finishes hold their appearance for decades if kept clean and can be refreshed with proprietary alu cleaner if they dull.

The AWS range is not glamorous, but that is the point — it is a competent, well-supported window system that a fabricator can build and fit reliably. Get the depth right for your project's thermal target, pick a good local installer, and the window part of the job becomes the least of your worries.