Ask the Expert with Hedgehog Aluminium

27 March 2018

Your FAQs About Bi-Folding Doors

The Sky House Design Centre understands that choosing bifold doors is a complete minefield, which is why we want to help in answering the frequently asked questions with the help of the experts in Hedgehog Aluminium.

We sat down with our Bifold experts, Hedgehog Aluminium for advice on some of your most frequently asked questions:

What is a bifolding door?

Bifolding Doors by Hedgehog Aluminium

A bifold is a series of individual door panels that are connected in pairs with hinges and mechanics. The panels are then folded back this opens the doorway.

Why are bi fold doors so popular?

Bifold Doors by Hedgehog Aluminium

Bifold doors are commonly used to connect rooms to outdoor spaces such as the conservatory or garden. Bi folding doors allow you to open up almost the entire doorway which really helps connect the two areas.

Are bifolding doors bespoke?

Bifolding Doors from Hedgehog Aluminium

Bifolding doors for external use should be made based on a system. That means they have been fully designed and tested for weather resistance, security and thermal insulation. However, the bifold door system can then be manufactured in any size and finishing to suit the client and site requirement.

Can the designer or architect choose the colour or finishing?

Hedgehog Aluminium Bifolding Patio Doors

Aluminium bifolds not only offer frames with fantastic strength but provide a huge choice of colours to choose from.

Most bifold doors will come with a range of standard finishes which offer the best in terms of cost and speed of delivery but you can choose to have the frames powder coated any RAL colour.

The thermally broken insulated framing is polyester powder coated, providing a choice of 200 colours and available in a marine grade finish.

How energy efficient are bifold doors?

Bifolding Doors by Hedgehog Aluminium

As long as your bifolding door includes a well-designed 'thermal break' aluminium door you will receive an energy efficient door system.

This thermally efficient frame should then be paired with a well insulating glass unit with an argon gas filling and low e coating.

The overall thermal performance will depend on the size of the panes and the configuration but as long as you make sure you have the thermally broken frame and glass unit with a Ug value of at least 1.1 then you'll get a good performance.

Can you take away the existing doors and windows and replace them with a bifold?

Bifolding Doors

It is absolutely possible to replace existing patio doors with an aluminium bifolding door.

If it is a straightforward removal and replacement than a FENSA approved company like Hedgehog Aluminium will be more then able to do that.

If door openings need to be enlarged or altered you will need to get a builder to create the openings and then we would come and install the bifolding door within them.

Most replacements will not need planning permission (as long as you use a FENSA approved company) however it is always best to check with your local planning authority to make sure.

Can I get frameless bifolding doors?

Bifolding Doors

Not for external use. When you have a bifolding door between the inside and out, the panes need to fully weather seal together to protect the inside from rain etc. You can't do that without a frame.

If the bifolding door is to be used as a partition between spaces, or as a wind protection barrier or external garden structures then yes you can have them frameless.

What is the slimmest frame I can get?

Bifold Doors from Hedgehog Aluminium

For an aluminium bifolding door you can get a very well-engineered bifolding door with a 120mm sightline.

This is the frame across the frame of two door leafs when they are closed. Hedgehog Aluminium also offer a 94mm sightline bifolding door as part of our Sieger Range but this has a reduced maximum height of 2.2m tall.

What opening options are possible?

Bi folding Doors from Hedgehog Aluminium

Bifolding doors are available in openings from a 2 panel to a 7-panel set, with a range of opening configurations available to suit individual needs.

Configurations can include a traffic door depending on the number of panels. You can have the panels folding left or right, one direction or have them completely split and arranged to slide in both directions.

What is a traffic door?

Bi Folding Doors by Hedgehog Aluminium

A traffic door is a single panel that acts the same as a normal traditional door providing easy access without having to open the whole bifold system. Bifolds in an odd number include a traffic door as standard.

How large can a Bifold door be?

Hedgehog Aluminium Bifold Patio Doors

You can expect to see a maximum panel size of 1200mm wide x 3000mm high for most bifolding door systems. Systems with much narrower sightlines (like our Sieger 94 system) will have a reduced size as the frames cannot hold as much glass.

Do you need planning permission for bifolding doors?

Hedgehog Aluminium Patio Doors

Planning permission is not normally required when replacing existing doors with bifolding doors. However, we would recommend you check with your local authority. Listed buildings or houses in conservation areas may require planning permission so you must check before taking action.

Where can I see some bifolding doors in person?


We have all our bi-folding door systems on show at the Sky House Design Centre (along with a lot of other aluminium windows and doors!).

You can either call us on 01494 722 882 or send us an email to to book your one to one consultation with one of our sales team. We can then run through the systems of interest with you in person.

Thanks, Hedgehog Aluminium - that is some great insight into the complicated area of bifolding doors. If you have questions that you would like to know the answers to or further information then please contact us. We would be happy to get one of our team members to get in touch or arrange the answers to be posted on our page.

We hope you found this Q&A with the experts, Hedgehog Aluminium useful and we very much look forward to seeing you at the Sky House Design Centre very soon .


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