The ultimate guide to buying bifold doors

What to look for when buying Bifold Doors

This guide aims to help you make a decision as to whether Aluminium Bifold Doors would be the ideal solution for your home.

  • What is a Bi-fold door?
  • Thermal Performance
  • Material and maintenance
  • Opening configurations
  • Price
  • Security
  • Accessibility
  • Installation
  • Colour
  • Are Bifold Doors made-to-measure
  • Suitable for older homes?

What are Bifold Doors?

A Bi-fold Door is sometimes referred to as a Concertina Door or Folding Sliding Door.

It is a system of door panels which slide along a track and stack together, opening up a home allowing easy access to a garden and letting the natural light flood in.

Bifolding Doors can have as few as 2 door panels giving the illusion of space in a smaller property, up to 6 door panels opening up a space of 6 or 7 metres, essentially, opening up the side of a property.

It is possible to have more than 6 panels by simply joining two sets of Bifolds together, as long as this is stipulated at the time of manufacture.

KAT Kawneer Aluminium Bifold


Are Aluminium Bifold Doors Thermally efficient?

Yes, they are thermally efficient. By fitting toughened double glazing filled with argon gas to all KAT’s aluminium bifolds, we are able to achieve low U-values to keep your home warm.






What material is good for Bifold doors?

Aluminium is strong and durable and requires very little maintenance.

Other than ensuring the track remains free of grit or dirt, a regular wipe with a damp cloth is all that is needed.

There is no need to paint your KAT aluminium Bifold as the paint finish is guaranteed for 10 years.

Can I choose which way the Bifolding doors open?

It can be useful to have one main traffic or lead door which can be opened throughout the year independently of the other sliding doors. This traffic door would operate as a single door unless you choose to unlock the other door sashes and slide your bifold door open to allow your garden and home to merge seamlessly. All of the bifold door sashes can slide to the left or the right, or you can specify if you would prefer one sash to slide one way and the other sashes another. You can choose whether your bifold doors open outwards, into the garden, or inwards into your home. In most circumstances, homeowners choose their doors to open outwards, this way you don’t need to move any of the furniture inside your home. Give consideration to the space in your garden where the Bi-folding doors will open onto, you’re likely to have door sashes at approx. 1m wide, so these sashes will need somewhere to stack when open, without becoming an obstruction. Download a KAT brochure.

Bifold Doors

KAT Kawneer Aluminium Bifold Doors

Bifold Door

Anthracite Grey KAT Aluminium Bifold Door











A good quality aluminium bifold door will be guaranteed for 10 years and is likely to last longer than that, so it would be a good investment. How much it will cost will depend on the size and the quality of the product. For more information on pricing, we can recommend a Design Partner who is local to you who will provide you with a price to supply and install a bifold door, bespoke to your requirements.

How secure are Bifold Doors?

KAT’s Kawneer Aluminium Bifold Doors have been tested independently and meet PAS24 security. The main traffic door has a lever lever handle and multi-point locking, whilst the intermediate doors are secured with a shoot bolt, operated by an intermediate handle.















Many homeowners ask if it’s possible to have a level threshold between the home and garden. It is important to consider whether your garden is in a sheltered area or whether you are open to the elements. If a low threshold is required, we can manufacture Aluminium bifolds with a 24mm thermally broken threshold which is not severe weather tested. The standard threshold is 45mm with a full weather rating.

What needs to be considered when installing Bifold Doors? 

Full installation guidelines are available on the KAT website, with step by step illustrations.

What colours are Aluminium Bifolds available in? 

One of the advantages of choosing Aluminium for your Bi-folds is that Aluminium can be painted in almost any RAL colour. Anthracite Grey is a very popular colour for Aluminium Bifold Doors at the moment. If preferred, the doors can be painted one colour on the outside with a different colour on the inside, to complement your interior design. KAT offers a luxurious textura finish as standard, with no additional cost, in addition to a matt or gloss finish if preferred. Take a look at our gallery of images.

Can Bi-folding Doors be made to measure? 

Some companies manufacture Bifold doors in standard colours and sizes. At KAT, every one of our products is made to bespoke dimensions to suit your project and can be delivered straight to your door. If choosing one of KAT’s standard colours, your door can be manufactured in just 2 weeks from the date of order. Contact KAT

Installing Bifold Doors in an old house

In an older house, Bifold Doors can be made to your bespoke sizes to fit either an existing opening or for an extension, allowing plenty of natural light to flood your home. As Bifold Doors can be made up to 7 metres wide, you may need to consider installing structural support. It is advisable to check whether planning permission is required or whether this would be classed as Permitted Development.

If you would like any further information, please visit, email [email protected] or telephone our Customer Services Team on 01625 439666.