Sheerline Aluminium Windows

Sheerline Thermlock® is a cutting-edge thermal break system designed to deliver superior energy performance without compromising on fabrication efficiency or structural integrity. Unlike standard polyamide inserts, Thermlock® features a multi-chambered design that significantly reduces thermal bridging within the aluminium frame. This allows you to offer clients products that comfortably meet or exceed current Part L regulations, with U-values as low as 1.0 W/m²K when triple glazed. It’s an ideal solution for trade professionals looking to provide high-performance, future-proof doors and windows.

Beyond thermal performance, Thermlock® adds real-world value on the shop floor and on-site. Its integrated, beadless design simplifies fabrication and enhances security by reducing vulnerability to glazing bead removal. The internal thermal chambers also add rigidity, making the frames easier to handle and more robust during installation. With Thermlock®, you get a streamlined fabrication process, a high-spec finish, and peace of mind that you’re delivering a top-tier aluminium system built to last.

Sheerline Classic aluminium windows are a smart choice for installers who want a sleek, modern look without the usual hassle. Built around Sheerline’s Thermlock® multi-chamber system, they deliver impressive thermal performance without relying on traditional polyamide barriers, so they are easier and quicker to fabricate and fit. With slim sightlines, these windows allow more light to enter and provide a clean, contemporary finish that suits both modern builds and replacement projects.

From a trade perspective, the Classic range ticks the right boxes: clip-in beads, neat gasket lines, and strong corner joints mean fewer headaches on-site. These windows are some of the warmest on the market, as they offer U values of 1.5 W/m²K with standard double glazing; around 1.1 W/m²K with triple glazing. They’re PAS24 certified too, so they’re ready for new builds or anything needing Part Q compliance. Available in a range of colours—including dual colour options—most specs are held in stock, resulting in shorter lead times.  Moreover, choose from options including contemporary, stepped, flush stepped, and flush contemporary. The coordinated style ensures that the windows blend seamlessly with the doors for a sleek and modern finish. 

Sheerline Prestige aluminium windows are built with flexibility and performance in mind. Designed for more demanding projects, thealuminium windows features a unique reverse butt joint option. This is a clean, flush external finish that eliminates bulky mullions, providing a more refined look, especially for multi-part windows. These windows deliver U values of approximately 1.4 W/m²K with double glazing; and  0.9 W/m²K with triple glazing, alongside deep thermal breaks and Sheerline’s Thermlock® technology. As a result, homeowners will benefit from a warmer home and lower energy bills.