Window Supply Company is the only fabricator of the Liniar profile in Scotland, the most technically advanced uPVC window system in the UK. The Liniar profile is completely designed from scratch and is the first brand new profile of its kind in the UK in nearly two decades.

With unrivalled energy efficiency and a design that addresses the ongoing issues of older profiles, the award-winning products from Liniar are market leaders. With a focus on research, development and design, the Liniar range continues to push the boundaries when it comes to product innovation, particularly in the area of thermal efficiency – the single most popular reason people replace old windows and doors.

Continued investment in infrastructure, technology and people has brought market-leading success, substantial growth, and recognition as a leading force in innovation.

How Liniar PVCu profiles work

PVCu is a natural insulator, so it is one of the most energy-efficient materials for a window frame, multiple chambers act as barriers, making it difficult for heat inside a property to be transferred through and escape outside.

Patented designs

Liniar has patented additional features that make its frames more energy efficient

Spacer bars

Warm edge spacer bars can be selected, separating each glazed panel for higher energy efficiency

Thermal dam

A patented thermal dam creates a multi-chamber thermal barrier at the frame’s outer edge


Profiles accept double or triple glazing

Bubble gasket

Patented bubble gasket is co-extruded alongside the frame so no heat loss or leaks

Glazing flipper

Unique glazing slipper creates a thermal barrier to seal the perimeter keeping the cold out

Why we choose Liniar

The most technically advanced uPVC window system in the UK

Environmentally friendly

Liniar profiles are manufactured using 100% lead-free materials and are fully and easily recyclable


The award-winning profiles from Liniar are completely designed from scratch to take advantage of the very latest developments in window engineering technology. Liniar continues to invest in research and new product development to push the boundaries when in product innovation

Thermally efficient

Thermal efficiency is the single most popular reason for replacing old windows and doors. The revolutionary Liniar profiles are far more thermally efficient than traditional uPVC profiles. By removing unnecessary steel reinforcement, instead of developing the latest in multi-chambered technology, heat is maintained inside

British made

Liniar design and manufacture their products from their headquarters in Derbyshire and the factory boasts the largest PVC mixing plant in the UK