ALUK Optio BSF70 Aluminium Bifolding Door



ALUK is a leader in the design and manufacture of aluminium sliding and folding doors, delivering outstanding reliability, performance and design every time. Our range of bifolding doors enables you to expand your living space by opening up wide expanses of your external walls to your outside space. Whilst at the same time keeping the weather out and the heat in during cold months.

Our stylish but practical bifolding doors are built to your needs, offering you a bespoke solution every time, from the configuration of the doors to the handles, accessories and colour, making ALUK bifolding doors the perfect addition to your home.

  • Wide range of configuration options
  • High performance glazing and design
  • Minimal profiles for a modern look
  • Complete range of handles and accessories
  • Unique flush line pop-out handle option
  • Full range of standard and bespoke colours
  • Dual colour option for inside and out
  • Chamfered and square bead options
  • Tested to PAS24 for enhanced security
  • Sturdy and reliable sliding mechanism
  • Low threshold option for room dividers
  • High performance as standard
  • Can easily be combined with all ALUK window and door systems
  • U-value = 1.7 W/m2K



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Why choose ALUK Optio BSF70?

Here’s why the ALUK Optio BSF70 bifolding door is so popular.

10 year guarantee

All of our ALUK Optio BSF70 aluminium bifolding doors come with a 10 year manufacturer’s warranty, giving you ultimate peace of mind.

Unparalleled thermal efficiency

With glass u-values as low as 1.0, our ALUK Optio BSF70 aluminium bifolding doors have some of the best thermal ratings of any bifold.

Made from durable aluminium

Our ALUK bifold doors are made from durable aluminium, making them strong and lightweight compared to other bifolds.

Transform your home with an ALUK Optio BSF70 aluminium bifolding door

Bring the outside in with a bespoke slimline aluminium bifolding door from Bifolding Doors Online. Transform your kitchen or dining area to create a flawless opening to the outside, producing a modern and alluring living space you and your family will be certain to enjoy.

Not sure what style of bifolding door would be best for your home? Get in touch with us today to speak with one of our friendly team who will advise you on which is the best bifold for your needs.

Keeping the weather out

The thermal efficiency of our ALUK Optio BSF70 aluminium bifolding doors has been guaranteed by the elimination of cold bridging, achieved by isolating of the external profiles from the internal ones. Combined with high performance glazing, the Optio’s ability to reduce heat transfer is in a class of its own.

With complete roof u-values from 1.0w/m2K Optio provides your home with a room that’s comfortable all year round.

Stress-free bifold shopping

  • Free UK delivery

  • No hidden fees or costs

  • Completely bespoke and made to measure

  • 10-year manufacturer’s guarantee

Optio – strong & secure

Profiles feature EPDM high quality gaskets and weather brushes to aid weather resistance. ALUK Optio BSF70 complies with the requirements of Building Regulations Document L 2010, and if that wasn’t enough, security is assured by multi-point lock mechanisms on main opening sashes, and shoot-bolt locking on floating mullions.

Attention to detail

All ALUK Optio BSF70 doors have the option of either low thresholds for unimpeded, easy access, or rebated thresholds that offer improved weather resistance.

Optio doors are available in a choice of standard or non-standard colours, including metallic, wood-structure, dual colour and Smart’s unique Sensations range of textured finishes.

A range of colours

Our standard colours are gloss white, matt grey and matt black. These can be chosen in any internal and external combination. 

We also supply your aluminium bifolding door in any bespoke colour of your choice. Simply find out its RAL or BS code and call us on 0845 139 0329.

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Our most frequently asked questions regarding aluminium, PVCu, and timber bifolding doors all in one handy place. If there's anything you still need to know, give our friendly team a call.

What is a u-value?

The U-value of a product measures how effective its insulation properties are. The lower the U-value, the better the insulation. As a guide, a standard double-glazed window typically has a U-value of 2.8 W/m². Our super insulating units achieve a U-value of 1 W/m².

What is the largest bifolding door you make?

Our aluminium and PVCu bifolding doors can have leaves as wide as 1200mm and 2500mm high. We can effectively manufacture as large a bifold as you would wish by adding in support in the form of floating mullions to the door.

How long until my bifolding door is delivered?

Aluminium and PVCu bifolding doors are usually delivered to your site within 10 - 15 working days, however this can sometimes be longer depending on manufacturing load and delivery schedules. Please be advised that glass may occasionally arrive a day or two after the frame.

What are your payment terms?

Payment terms for normal orders are strictly pro-forma, using Visa, Mastercard, bank transfer, or Paypal. 

What is a thermal break?

A thermal break is a material with low thermal conductivity that is placed between two different conductive materials. Its job is to reduce or prevent the flow of thermal energy. In our products, these thermal breaks include resin, silicone and styrofoam, which separate the conductive aluminium components to provide superb thermal insulation.

What is the maximum width of a bifold leaf?

We can produce bifolds with a maximum leaf size of 1200mm.

How do I get a price?

Simply visit the relevant product page and choose your bifold's required sizes for an instant price.

What sizes should I measure?

The measurement we work from is the brick-to-brick size of the opening.

Still have questions?