The ultimate Slimline uPVC Window

For a sleek profile and outstanding performance.

Meet SlimJim, the slimmest uPVC window available and exclusive to Thermaglaze.

Ultra-slim sightlines give the SlimJim window its elegant style and a timeless look to any property style. Perfect for a modern or traditional home, you’ll love the finish it provides.

Thanks to the increased glass surface area of our SlimJim windows, you can create a warm yet airy home flooded with natural light.


Perfect for both modern and traditional properties…

This sleek window style is ideal for both modern and traditional properties. Depending on the style and size, as much as 12% more light can be gained through our Slim-Jim windows, compared to other typical uPVC systems.

Our engineered Slim-Jim Windows are designed to
fit with any typical British home. The aesthetic design ensures that your windows will enhance the look of your property, rather than detract from its overall appearance.

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Bespoke Design

As with every project we undertake, our team of glass and glazing experts are on hand to help you design a bespoke window to suit your property’s style.

We can tailor your new Slim-Jim windows to create either a modern or established look. Our exclusive Slim-Jim windows are also available in a whole range of colours to suit any property.

Our Slim-Jim windows are extremely energy efficient, and have been awarded an energy index rating of ‘A+’.

Its impressive energy rating guarantees that your home stays warm and dry all year round, and in the process, helps to cut the cost of your household bills.

Your new Slim-Jim windows will be completely draught proof and watertight. The Slim-Jim profile is produced with all weather bubble gaskets (seals), fused to both the inner and outer frame section.

The bubble gaskets are hollow and offer greater compression and remain in-line with the profile for a neater appearance. They are fused to the profile, which means they can never shrink back, reducing the chance of leaks or unpleasant draughts in your home.

Naturally, you want to be assured that the quality of the installation will match the quality of the products. As a CERTASS registered company we work with an agreed code of practice, which includes a full understanding of the building regulations and the other CERTASS requirements.

Prior to your installation, a full and accurate survey will be carried out. The survey will ensure that your desired style of window will combine effectively with your home.

Optimised Security
Shootbolt Locking System
Security Glazing

Enhanced security features

We source and install the highest quality products and materials, giving you that peace of mind that your home and family are safe and secure.

We never cut corners, and we do not compromise on safety when it comes to our exclusive Slim-Jim window range.

Get in touch

A friendly no-pressure sales team, time to browse and discuss products in their showroom, simple ordering process and good communications by phone and email, confirmed by post. Friendly, careful surveyor who ensured that the right product was constructed for us and a very professional, patient, tidy and cheerful installer whose work we will be impressed by every time we come home. We would thoroughly recommend Thermaglaze and ” the products they have fitted to our home. Thanks team!

Kirstin W. Everton

Graphic Designer, Apple

Andy Guscott

Developer, Google

The Thermaglaze Family

Like the look of our service and products but not based in our catchment area? Take a look at our 2 sister companies in the surrounding area.

Clearglaze Windows

Based in Bath, we cover the following areas: Bradford on Avon, Radstock, Keynsham, Chippenham, Saltford and Midsomer Norton.