The SUNFLEX SF55e bifolding door review

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Nick Dardalis

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SUNFLEX enjoys a 30-year reputation, providing some of the best bifolding doors on the market.  The SUNFLEX SF55e bifolding door is their latest product joining their other six, premium and German-made folding sliding doors.

The SF55e bifolding door is designed to provide a high specification bifolding door at an attractive price. If you are researching a new bifold and looking at brands such as Schuco, Origin or Reynaers; then read on.  We explain in detail Sunflex’s new bifold, tell you about its stand-out features and explain reasons to consider it with the other well-known names.

sunflex sf55e bifolding door

Sunflex SF55e bifolding door: the product and the brand.

SUNFLEX is a premium brand with award-winning bifolding doors and other home improvement products.  In their folding range there are doors in aluminium, timber and timber clad aluminium. There is also a slimline bifolding door for internal applications such as room dividers.

Designed and made in Germany, the doors are supplied in the UK through a network of professional installers, carefully chosen by Sunflex. Also available to homeowners are sliding patio and slide and turn doors. Homeowners additionally get a range of windows, front doors and glazed roofs.  Finally, for the outside or commercial buildings, moveable glass walls and stacking door systems add to the range.

Talk to professional installers or architects and the SUNFLEX name has a perception of quality, excellence and expertly crafted doors. There are several German bifold patio doors available in the UK, with many of these also enjoying a good reputation.   Additionally, many of the long-established home improvement companies, specialising in the upper end of the market also sell Sunflex exclusively or alongside other luxury brands.

However, with a premium brand also comes an extra cost. For years the SF75 and SF55 models hold the top spot, illustrating the best in German design and quality.

Today the company has a lot more competition with so many systems and brands to choose from.  Although SUNFLEX remains a desirable and well-known name, customers certainly have much more choice and awareness of other brands.  For instance, Schuco, Origin, Reynaers, Solarlux or Centor all offer well-made, high specification doors at good prices. SUNFLEX’s SF55e bifolding door allows homeowners without the top-end budget to benefit from one of the best German brands at the same  ‘mid-range’ price of these other popular doors.

Comparing SUNFLEX bifolding doors.

Even though this new door costs less than the others in the range, it retains virtually the same specifications. Our review of the enhanced SF75 and SF55 models explains more.

The rationale behind the SF55e is a more affordable luxury bifold door without compromising on features.   Visually there is little to tell them apart, and they don’t scrimp on specification either.   Here is how the three different doors compare where it matters.

Comparing SUNFLEX Bifolding Doors
Features SF75 SF55 SF55e
Made in Germany
Door Mullion Sightline 115mm 115mm 115mm
Maximum Panel Width 1100mm 1200mm 1200mm
Maximum Panel Height 3500mm 3500mm 3000mm
Threshold Options Two Three Three
Mitred outer frame
Secured by Design
Contemporary Square Appearance
Midrail Option
BSI Kitemark™
Inline door handles
Overall Double Glazed U-Value 1.4 1.6 1.6
Integrated Window
Exclusive door catch and clip
Same range of colours and finishes

Every one of these three different aluminium bifolds shares the best features.  Importantly, we must highlight why, in our view, SUNFLEX has got the SF55e bifolding door spot on. They are not unique in providing several bifolding door models.  Many other systems do too.  However, with other brands, it is easy to spot the differences.

For instance, the years-old Smart Systems Visofold 1000 is easy to differentiate from their latest slimline 6000.  The Aluk Optio BSF70 bi-fold door is easy to spot as the cheaper model than their latest Luminia F82 bi-fold door.  With some brands the aesthetic, design and cost-saving differences across the different models are apparent. Not so with the SF55e.

bifolding doors for large openings.

Why the SUNFLEX SF55e bifolding door is cheaper.

Ordinarily, only a trained eye sees the aesthetic differences between the premium SF75 or SF55 and the new SF55e. The outer frames, door sash profiles and other aluminium sections are the same. At the same time, any differences are so subtle, the customer buying the cheaper “e” model will not feel short-changed.  All these doors share a lot in common. However, there are still reasons to consider the more expensive models. The SF75 offers a solution for customers wanting better thermal performance.  With the SF75, there is also the option to incorporate an opening window within a door for ventilation.

Moreover, the attractive price point of this door comes down to just three reasons instead of many.  And again, none of these implies a ‘lesser’ or inferior door to the SF75 or the SF55.

Different Door Hinges.

First of all, the SF55e comes with bigger door hinges.  The reason for this is integrated hinges and running carriage on the ‘e’ version. This integrated design places a greater load on the door hinges and bigger as a result.   By comparison, SF55/75 doors have separate hinges and running carriage, therefore having smaller hinges taking less load on them.

Different Door Gaskets.

Secondly, the more expensive SF75 and SF55 bifolding doors come with no less than 12 different types of door seals.  The “e” model comes with fewer.  Of course, there is no compromise in weather resistance and sealing.  The gaskets are just different.

Less machining and manufacturing.

The third is reduced machining and manufacturing time. Even though every one of the three models uses the same frame and door profiles, the SF55e requires less time in the factory in spite of this.  The price consequently reflects this reduced factory time.

black sunflex bifold doors

Reasons to buy the SUNFLEX SF55e bifolding door.

Throughout our website, we talk about most of the brands in the UK.  For instance, Origin doors are outstanding, namely with phenomenal lead times, an excellent dealer network and a 20-year guarantee.  Schuco doors also offer  German engineering with high availability as well as slim sight lines. Reynaers doors also enjoy an excellent reputation with impressive products all round.

However, the SF55e provides beats the other brands in several areas. For instance:

  1. 115mm sight lines.  The SF55e is thinner than Origin, Schuco, Reynaers and thinner than all the other popular brands. You get more glass with discreet and elegant doors as a result of these thin door profiles.
  2. 3.5-metre height.  Although most customers won’t need an SF55 this tall, this size capability is a testament to its top-of-the-line design.
  3. A mitred outer frame. Another stand-out feature with the other brands having a square cut frame. See the doors, and you’ll agree the mitred frame looks genuinely better.
  4. Consistency in Quality.  Doors made in one factory not in many different places.
  5. Colour matched hardware.  With the other brands, colour matching your hinges and handles usually comes at extra cost or not available.
  6. Special colours such as brushed steel effect or textured finish, often unavailable with the other brands.
  7. A weather-tight low threshold without sinking the standard frame.

Another prominent feature of these doors is the all-important panel catches.  Furthermore, study the door catches on a SUNFLEX door and then compare to the magnets and catches on other brands.  In other words, these doors offer highly engineered catches that look great and perform brilliantly. It really is about the fine detail.

sunflex door catch
A well-engineered SUNFLEX door catch better than conventional magnets.

Other features of the SUNFLEX SF55e bifolding door.

The choice of three thresholds is another consideration too.  Generally, many good brands provide reliable door thresholds.  Specifically, this door offers a double rebate on the bottom track where other doors only come with a single rebate.  At the same time, design the floor detail right and also enjoy a step down to your garden as small as 3mm.

You can expect certified security, namely Secured By Design. These are also the only German-made doors with the BSI Kitemark.

For colours, you get the full range such as RAL colours and different colours inside and out too. Furthermore, you get woodgrain bifolding doors such as those by Origin or Smart Systems woodstructure range.

The only consideration with these doors is lead times.  On the one hand, these doors won’t come on Origin’s unbeatable lead times.  On the other hand, anyone wanting a German-made door expects to wait a little longer.

We should also point out that only the bifolding doors are made in Germany. Sunflex’s range of sliding doors, windows, front doors and lantern roofs are made in the UK.  You can read our separate review of the SF75 and SF55 models too. 

Any of the brands mentioned in this review will give you a door in your home you’ll be delighted with.  However, a premium and well-engineered bifolding door generally provides a better product besides the basic folding door concept.

Above all, with a SUNFLEX door, you enjoy a reputable and sought-after brand of bifolding doors with several standout features. In particular, the thin sight lines being the most impressive.   For this reason, if you think a SUNFLEX door out of your price range, then get a price for the SF55e.

Contact us for more information.

For answers to questions about the SUNFLEX SF55e bifolding door as well as any other patio door product and where to buy, contact us. Of course, we can also help with your general home improvement and aluminium product questions too.

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16:42 30 Oct 23
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07:03 11 Sep 23
Update - A second email to nick for help on bifolds resulted in a detailed informative reply even on a Sunday ! This guy is so knowledgable and helpful .I approached Nick for an independent view on sliding doors v bifold and the different brand options . His reply was extremely detailed and prompt and allowed me to navigate this often confusing world in a much more informed way . Thanks so much Nick
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