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 :


So we have seen so many different spellings of aluminium ( alaminium and aluminum being the two most common misspellings.) Aluminium is a metal who’s chemical element is Al. It makes up 8% of the earth’s crust. As it is particularly resistant to corrosion it is an important metal in the transport, aerospace and building industry. It is lightweight, durable and non magnetic and can be powered coated in over 200 different ral colours to suit your project.

Astragal Bars

An astragal bar is a moulding that appears to separate a glass pane.  They are fixed to a sealed unit and give the appearance of multiple panes of glass – like a Georgian window. Georgian bars are normally fixed within the sealed unit where an astragal bar is fixed on the external surface. You can find out more about astragal bars in our post.

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. You can find out more about the glass in your windows.

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.  You can find out more about U-values.

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).