Bi Fold

We have looked at bi-fold doors for a long time, after much deliberation we have decided that to ensure we have a product we are confident will last, aluminium is the only option!

Our supplier has created the FIRST secured by design accredited bi-folding door, this is a fantastic achievement and again is possible because they are pioneers in their field.

We only deal with the highest quality materials and manufactures so you can rest easy knowing that you are getting the best availiable products at the best value price!

Aluminium is a good conductor of heat, meaning that without some extra features, your property will loose more heat on a cold day than one of our standard PvC or timber windows. It will be no surprise that at Keswick Superglaze we have not just accepted this as a drawback of using aluminium. What we use on both our windows and doors is a metal frame but with a thermal break* in the middle. This achieves minimal heat loss up to the latest building regulations whilst maintaining its extremely strong and secure structure.

The smaller finishing details such as the convex magnetic fitting have not been overlooked. Although one of the more minor details, having a curved magnet helps to perfectly align and connect the doors together on opening.

* The thermal break is a rigid plastic layer in between aluminium frames on each side.


The Glass

After using the highest quality frames, we need glass to the same standard. From Durham, our manufacturer has been established for over 50 years. They are also constantly investing in new products meaning they are at the pinnacle of what is possible.

Check out the video below which shows how a new glass innovation can actually change opacity depending on the environment! This is possible due to an electric current passing through the glass.

Dynamic Solar Control Glass

Our benchmark starts at an A +, so there is not extra cost to upgrade. On all of our glass units* we use a warm spacer bar. This is a little bit more expensive than a standard aluminium one, however it is one of the biggest leaps forward in glass and glazing over the last few decades – it is approximately 1000 times better! You may have noticed a condensation patch around the edges of your window and this is partly due to that spacer bar transferring heat better than the glass. Our warm spacer bar will greatly improve this phenomenon.

We also tailor aspects of the glass further depending on what our customers want to get from their product.


– Is your furniture fading?

– Nearby road too noisy?

– Sun makes the room unbearably hot?

…We can offer glass which will mitigate all of these.


As an example, a standard double glazed unit will block out approximately 60% of UV rays, so 40% gets through and fades your carpets and furniture. We can install our ‘Armour Pane’ glass which stops 98% of these harmful rays!

We can also fit triple glazed units, however we feel that it is only in certain circumstances where the benefits of it would outweigh the drawbacks, double glazed units often out perform triple! Ask one of our salesman and they will be happy to discuss this as part of the quotation process.

* Unless the glass is to match existing windows