Understanding the Jargon

Here’s a brief guide to some of the common terminology and considerations that you may come across as you select your new aluminium windows, doors, shop fronts & curtain walling :

Building Regulations: Document L and Document Q

We will be able to answer any questions you have on Building Regulations, but there are two key elements of the regulations which affect windows and doors:

  • Document L - covers the insulation values of building elements
  • Document Q - covers the key security requirements for buildings

CE Marking

From July 2013, all windows and doors had to be CE marked in accordance with the Construction Products Regulation.

Glass Options

A wide range of glass options is available for your window and door system, with double and triple glazing, self-cleaning, gas-filled, anti-glare, coated, decorative and energy-efficient units just some of the options! We can help you choose the most suitable glass for your project.

Polyamide Thermal Break

Aluminium is also a very good conductor of heat, and on its own would provide poor insulation against the cold winter weather. The frames include a material which prevents the transfer of the heat or cold from the outer frame to the inner frame. This causes a barrier or thermal break and improves the insulation and energy efficiency of the windows or doors.

Security rating

Most window and doors will be certified to PAS 24 – essentially this means that the manufacture of the product has been monitored by an accredited certification body. This is a minimum standard - it doesn’t include higher or lower grades for security.


U-values are a measure of how good a material is as an insulator. The lower the U-value, the better insulator. Typically between X and X

Weather Performance

Windows and doors contribute to a building overall weather performance, including its resistance to water ingress and its air-tightness. Manufacturers test their window and door systems to make sure they meet the required performance standards.

Window Energy Ratings (WER)

The Window Energy Rating (WER) scheme provides a measure of a window’s energy-efficiency. The system is based on a simple A+ to G scale (with A+ being the most energy-efficient).