trade alitherm 400 windows by smart

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A black circle with the text '1.1 U Value' in white.
Black circle with the words 'Thermal Break' in white center.
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smart alitherm 400 casement windows

The Alitherm 400 range combines exceptional value with high-quality design, offering stylish and energy-efficient window. With class-leading performance and security, it’s an excellent choice for homeowners looking to enhance their property with durable, thermally efficient aluminium frames.

Designed to deliver both aesthetics and functionality, Alitherm 400 ensures a sleek, modern look while maintaining outstanding strength and insulation.

colour options

solid dark gray background

Black

Black and white abstract lion head illustration with intricate tribal patterns.

Anthracite Grey

Empty white background

White

Black and white triangle pattern, upper right corner black, lower left corner white.

Black / White

A diagonal split between dark gray and white.

Grey / White

Modern two-story house with large windows, sloped gray roof, and wooden accents, surrounded by greenery and a small front lawn.

alitherm 400 WINDOW FEATURES

- Single & Dual Colour Options

- PAS 24:2022 Approved

- U Values: 1.4 Double Glazed 1.1 Triple Glazed

- Part L Compliant

- A+ Energy Rating

Why the Trade Chooses Alitherm 400 Windows

Alitherm 400 Windows are designed for both residential and light commercial properties, fully compliant with the latest building regulations. The co-extruded gaskets in the sashes, outer frames, and Smart Quick-Glaze Beads make fabrication easier and installation faster.

These windows offer exceptional thermal and weather performance. PAS 24:2022 approved for enhanced security, Alitherm 400 is the ideal choice for new builds, refurbishments, and a wide range of projects, trusted by trades across the industry.

Open awning window with garden view

configurations

Smart Alitherm 400 windows are available in top & side hung as well as fixed configurations.

Close-up of a cross-section of an aluminum window frame with double glazing.

quick glazing bead

A game-changer for installers - pre-fitted wedge gaskets in the glazing bead help save hours on installation.

Open window frame showing a view of a lush garden with green grass, palm trees, and various plants against a blurred background.

u-values

They help keep heat in, with a rating of 1.4 using double glazing and an even better 1.1 with triple glazing.

Built for Modern Standards

Alitherm 400 Windows are designed to meet the latest 2022 building regulations, ensuring compliance without the guesswork. While many aluminium windows fall short of these new standards, Alitherm 400 gives you peace of mind with performance you can trust.

alitherm 400 FREQUENTLY ASKED QUESTIONS

  • Material: Aluminium Polyamide

    Dual Colour: Yes

    Thermally Broken: Yes

    NBS Available: Yes

  • WER Rating - A+

    U Value - Double Glazed 1.4 Triple Glazed 1.1

    Document L Compliant - Yes

  • Our standard Alitherm 400 lead times is around 3 weeks. Please note this is subject to change.

TECHNICAL SUPPORT

We’re committed to helping our trade partners win new business. As well as delivering high quality glazing products, for residential and commercial projects, we offer guidance, technical expertise and sales support.

From survey sheets to door adjustment tips, using our 30 years’ of knowledge, we’ll provide you with the tools necessary to deliver the best installation services possible.

Find what you’re looking for in our downloads section.