External bi-fold doors are a lot larger than your standard door, which means they have a much larger surface area for heat to dissipate through. This is why it’s extremely important that you can rely on the fact that the door you’re purchasing is well made and delivers high thermal performance to keep your heat in and the cold out.

Here at Aspire Doors we aim to deliver high quality doors that not only look great, but are also well made, long lasting, and out-perform standard thermal efficiency regulations. But what does all that mean? In this article we aim to answer your questions about external bi-fold door thermal efficiency.

What is a U-Value?

So, what does the U-value actually mean? U-values describe how effective a material is as an insulator. With external doors in particular, it looks at how well they keep heat inside your home, and keep the nasty British weather well and truly outside. Not only will this keep your home warm, but will mean you’ll use less energy heating your home, less energy will be wasted and oveall your heating bills will be reduced.

When looking for a new door and reading the U-Value, remember: the lower the U-value, the less heat is lost. So the lower, the better.

At Aspire Doors, all of our external bi-folding doors are compliant with – and regularly exceed – Part L of the UK building standards, which requires that all external doors should have a U-value of 1.8w/m2k or less.

Weather Proof External Bi-Fold Doors

The sturdy design of our bi-folding doors – with locking points in multiple places along the tracks, compared to a single locking point on a standard door – means that not only are they great for keeping out potential intruders, but coupled with our weather seals they keep the wind and rain out too. Being able to withstand the forces of nature is vitally important for the thermal efficiency of your home.

Quite often, second to windwos, doors are the biggest leak of warmth in your home, especially the seals around them. To ensure that external doors perform to a high standard, we use high quality materials to construct the door to ensure you get a well-made product.

Which Type of Door is the Most Energy Efficient?

When it comes to external doors, the two most common materials used are timber and uPVC. Although uPVC doors offer better energy efficiency than wood, they are less efficient to make. Wooden doors are much more environmentally friendly to manufacture, and also offer high levels of energy efficiency and low U-value ratings.

Looking specifically at external bi-fold doors, again there are two main materials that they are constructed from: wood and aluminium.

Aluminium Bi-Fold Doors

Aluminium is a light-weight metal and is naturally a poor insulator, so therefore aluminium has been considered to offer poor thermal efficiency in the past. However many aluminium doors now feature a ‘thermal break’. The thermal break is included within the construction of the door and is made from a conductive material, improving the energy efficiency of the door.

Wooden Bi-Fold Doors

Timber has long been used to manufacture doors due to its versatile nature, beautiful finish and the thermal properties offered by the finished door.

Wooden bi-fold doors offer many benefits, including those mentioned above, wooden doors can be painted to suit your internal decor. If you feel your doors need a change or colour, you can paint bi-fold doors to suit your taste.

Although timber bi-fold doors offer a slightly lower energy efficiency than aluminium doors (around 0.1W/m2), the benefits of their styling, finish and versatility are enough for many homeowners to overlook the minimal difference in thermal efficiency and consider wood over aluminium.

Find Out More

As expert door suppliers, all of our products are built to last, surviving the test of time for many years to come. To find out more about our external bi fold doors, or any of our products or services, please contact us.


Join Waiting List We will inform you when this product is back in stock. Please enter your email address below and how many you're interested in.