Windows / Aluminium Windows / Alitherm 400
Alitherm 400 Aluminium Windows
Class-leading performance and security in a range of stylish, energy-efficient aluminium windows — from standard casements to the newly-available Tilt & Turn option, built to the latest Document L standards by the UK’s largest aluminium extrusion manufacturer.
Who they are
Built by Smart Systems, part of the Corialis Group
Smart Systems has grown over forty years into the UK’s leading supplier of aluminium glazing systems, manufacturing from its own facility in Yatton with an in-house powder-coating line — keeping quality and lead times in-house rather than farmed out to a third party.
40+
Years established
No.1
UK’s largest aluminium extrusion manufacturer
Yatton
In-house factory & powder-coating
C2C
Cradle to Cradle Bronze certified
Why choose Alitherm 400
Class-leading performance, without the compromise
PAS 24:2022 approved
Enhanced security tested to the latest standard for aluminium windows, with key wind, lift lever or slam lock multi-point options.
Class-leading thermal performance
U-values from 1.4 W/m²K and a WER Band A rating, fully compliant with Part L of the Building Regulations.
Choice of styles
Standard, slimline, flush and heritage sash options, plus the newly-available Tilt & Turn — one system, several looks.
Unrivalled choice of colour
Dual-colour capability runs a different shade inside and out, finished in Smart’s own powder-coating facility.
Smart’s Quick-Glaze Bead
The first system in the UK to feature it – co-extruded gaskets pre-fitted into the sash, outer frame and glazing bead cut fabrication and installation time significantly.
Built to last, minimal upkeep
A high-quality system that needs little maintenance, delivering decades of trouble-free operation once installed – backed by Smart’s Made in Britain manufacturing.
Styles & configurations
One window system, six ways to open it
Every Alitherm 400 window style shares the same 70mm profile family, so a whole elevation can be specified in one consistent system — from a fixed light to the newly-available Tilt & Turn.
Side Hung
Top Hung
Fixed
Tilt & Turn
Flush Casement
Heritage
Colours & finishes
An unrivalled choice of colour
Alitherm 400 is powder-coated in-house across four Smart Systems colour collections — filter by collection, then click a swatch for a closer look. Dual-colour capability means the interior and exterior can run different finishes.
Request a painted sample of your chosen colour before making your final decision — screen colours are a guide only.
Get a Quote in this colourTechnical specification
Alitherm 400 at a glance
| Material | Aluminium, polyamide thermally broken |
|---|---|
| Frame depth | 70mm |
| Thermal performance | U-value 1.4 W/m²K · WER Band A · Part L compliant |
| Glazing options | 24, 28, 32, 36, 40 & 45mm sealed units |
| Colour | Dual-colour capability (different interior/exterior finish), full in-house powder-coat range |
| Window styles | Side Hung, Top Hung, Fixed, Tilt & Turn, Standard Casement, Flush Casement, Heritage Flush Casement |
| Max size – Side Hung | 864mm wide × 1400mm high · Air Class 4 · Water E1200 · Wind AE2400 |
| Max size – Top Hung | 1400mm wide × 1400mm high · Air Class 4 · Water E1200 · Wind AE2400 |
| Max size – Fixed | 2100mm wide × 2100mm high, max perimeter 42 (as published by Smart – see open items) · Air Class 4 · Water E1200 · Wind AE2400 |
| Max size – Tilt & Turn | 1200mm wide × 2100mm high · air/water/wind performance TBA (per Smart’s own published spec) |
| Security | PAS 24:2022 approved (Tilt & Turn: TBA) · key wind, lift lever or slam lock multi-point options |
Figures above are Smart Systems’ own published performance data for Alitherm 400 (smartsystems.co.uk and Smart’s Alitherm 400 brochure, ref. IMS609AL4) — Tilt & Turn’s full security/air/water/wind ratings are shown as “TBA” on Smart’s own spec sheet, not a gap on our side. The Fixed window’s “max perimeter” figure (42) is exactly as published, though Smart’s own table labels it in mm, which looks too small to be a real perimeter – worth confirming with Smart’s technical support before publishing.
Security & certifications
Tested, certified, and built to last
- PAS 24:2022 approved – enhanced security for aluminium windows
- Fully compliant with Part L of the Building Regulations
- Key wind, lift lever or slam lock multi-point locking options
- Suitable for residential and light commercial properties – schools, colleges, hospitals, offices and public sector housing
- Manufactured by Smart Systems in Yatton, Somerset – Made in Britain, Cradle to Cradle Bronze certified
Ready to spec your Alitherm 400 aluminium windows?
Get a price on your opening, in the style and colour you need.
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