Alitherm 400 
building regs compliant

SMART alitherm 400

Alitherm 400Quick-Glaze Pre-Gasketed Beading

Combining outstanding value and quality, with class-leading performance and security, the new Alitherm 400 system provides a range of stylish casement windows and single and double doors.

The system is perfect for a wide variety of projects, including both new build and refurbishment, residential and light commercial applications.

Alitherm 400’s design incorporates Smart’s innovative polyamide thermal break technology, which creates a barrier between the cold air outside and warm air inside, significantly reducing thermal transmittance and enhancing the system’s overall U-value.

The system is also fully compliant with changes to Document L of the Building Regulations, is rigorously tested to PAS 24:2016 as standard and exceeds the requirements for weather resistance and security performance.

Fitting Couldn’t be Easier…

The Alitherm 400 window is the first thermally broken aluminium system to feature Smart’s pioneering coextruded glazing gasket. This means the beads are supplied with the glazing gasket post-extruded into the profile. This enables the Quick-Glaze beads to be simply tapped in on site, significantly reducing fabrication and installation time.

Available with a flush or chamfered profile, the slim lines of Alitherm 400 provide excellent weather and thermal performance, as well as the security assurance provided by PAS24 accreditation. While the flush, flat face option is suitable for off-set, face-mounted espagnolette locks, the chamfered design features a eurogroove, to enable in-line espagnolette locking mechanisms to be used.

The system can also accommodate astragal bars to achieve different design requirements. 

Key Benefits of Alitherm 400 Aluminium Windows

  • Building Regulations Compliant – Fully compliant with changes to Document L of the building Regulations
  • Smart Quick-Glaze Bead – Featuring integrated gasket and ‘tap-in’ design for easier fabrication and faster installation
  • PAS 24:2016 Approved – Enhanced security for aluminium windows and doors
  • Unrivalled Choice of Colour – In addition to our 5 colour collections, we can colour match any RAL colour
  • Suitable for Residential and Light Commercial Properties
  • Low U Value – Achieves a U value of 1.4 as standard with double glazing


Alitherm 400 spec

Are Aluminium Windows Energy Efficient?

Alitherm 400 Windows deliver polyamide thermal break technology, which enhances the U value and earning an A rating on the Window Energy Rating with a U value as low as 1.4W/m²K. This results in lower energy bills and a more comfortable home environment.

alitherm window
alitherm 400 profile detail
alitherm 400 window profile detail
alitherm 400 window

Get a cost for aluminium windows here.