Who makes the slimmest bifolding doors?

The aluminium bifolding door offers a host of benefits in the home, but what are the slimmest bifolding doors available at the door mullions? With more bifolding door systems available than ever before, if you are a homeowner looking for a quality bifolding door, there is a tremendous amount of choice. One area you may be considering is the appearance and aesthetics at the door mullion.  For the trade, this article helps you compare the majority of the UK systems, useful to compare against the products you do sell.

Why choosing the slimmest bifolding doors matters.

One of the promoted features of the bifolding door is the ‘door sightline’. The door sightline is the visible aluminium you see on a closed set of bifolding doors.  This is where the door panels meet or referred to as the door mullion.  Another way of explaining it, is the glass-to-glass dimension on the meeting panels.

Our table illustrates the slimmest bifolds and the sightline of virtually every major aluminium bifolding door system available today. See how they compare in order of slimness at the door mullion and the sightline dimension you can expect to see.

Sieger Lux by IQ Glass	74mm
Origin OB-36+ Soho and Origin OB-36 Contemporary	84mm
Alumil Smartia MF65 same as Express Bifolds XP88	88mm
Schuco ASFD75	90mm
Smart Systems Visofold 6000	94mm
Aluco Aluminium steel-look bifold	94mm
Solarlux Ecoline and Highline	99mm
Solarlux SL80	105mm
Dutemann FD85 (Alumil SF85)	105mm
Express Bifolds XP Vision (Alumil SF85)	105mm
Alunet BF73 Bifolding Door (formerly Alutech)	107mm
Origin OB-49 Bifolding Door	110mm
Greenways Ultra Slim Bifolding Door	110mm
Schuco ASS 80FD	112mm
Sunflex SF75	115mm
Stellar Aluminium Systems Bifolding Door	117mm
Schuco ASS 70 FD	120mm
Comar FSDX Folding Sliding Door	120mm
Cortizo Bifolding Door	120mm
DeWall Bifolding door by Debar	120mm
StudioGlide by Eurocell (DeWall product)	120mm
Unifold by Arkay Windows	120mm
Deceuninck Decalu88 folding doors	120mm
Air 800 Bifolding Door	122mm
Smart Systems Visofold 1000 Slim	122mm
AluK Luminia F82 Bifold Door	122mm
Reynaers CF 77 SL	122mm
Senior Architectural Alifold Doors	123mm
Senior Architectural PUReFold Doors	123mm
Sunparadise Supertherm 80 Bifolding Door	124mm
Sunparadise Thermo 60 Bifolding Door	124mm
Stayfix Architectural Vision Fold Doors	125mm
Folding Sliding Door Company FD72	130mm
Velfac 860 Bifolding Door	130mm
Reynaers CF68	131mm
SAPA Crown Folding Door with slim sash	131mm
Smart Systems Visofold 1000	132mm
Korniche Bifold Doors by Made for Trade	133mm
Exlabesa Xlafold Bifolding Door	135mm
Centor C1 Bifolding Door	136mm
Sheerline Prestige Bifold Door	138mm
AluK Optio BSF70 Folding Sliding Door	140mm
Sieger Bifolding Door	140mm
Smart Systems Visofold 2000	141mm
Metal Technology Bifolding Door	143mm
Technal Ambial Bifolding Door	143mm
Reynaers CF77	144mm
Panoramic Slide and Turn Door	145mm
Kawneer AA3720 Bifolding Door	145mm
Stellar Aluminium Systems Bifolding Door	146mm
Kestrel Folding Sliding Door	150mm
Metal Technology System 26 HI+ Bifolding Door	153mm
Origin OB-72 Bifolding Door	154mm
Smart Systems Visofold 3000	154mm
Alumina by Liniar	156mm
Warmcore Bifolding Doors	156mm
Solarlux SL70	157mm
SAPA Crown Folding Door standard sash	165mm
Aluprof MB System Bifolding Door	166mm
Smart Systems Visofold 4000	185mm

How do we arrive at our list of the slimmest bifold doors?

The data for nearly sixty folding sliding door systems comes from the system company websites or their technical and fabrication manuals.  The above sightlines indicate the typical dimension where two intermediate panels meet. Sizes with some systems increase when a folding panel meets the traffic door if one is specified.  We excluded frameless and slide and fold doors operating on an individual moving and folding panel basis as well. Also excluded are systems that do not meet current Building Regulations.

However, two bifolding door systems are even thinner than the Origin bifold, Alumil Smartia, Schüco ASFD 75 or Visofold 6000 bifolding door, top of the list above. We did not include these two in the list above because these are structurally glazed bifolding doors made around the glass. The above systems are dry-glazed.

The Sieger Lux Bifolding Door.

Our research shows the overall slimmest bifolding doors on the market in the UK right now, to be the Sieger Lux product. This boasts impressive 30mm wide door sash profiles with integrated locking systems. As a result, these give an overall mullion dimension of 74mm.

Unlike the doors above, the Sieger Lux bifolding door comes structurally bonded and allowing the glass to take the weight of the product, reducing the aluminium sightlines as a result.  Studying the section drawings of this product reveals thermally insulated aluminium profiles, bonded to 28mm double glazed or 32mm triple glazed units.

Square edges, slimline door components, 3-point locking system, open corner option and traffic doors are just some of the standard features you get. Minimal aluminium frames combined with high specification glass units also provide U-Values of 1.6Wm2K depending on the glass used.  As well as this, you get the expected large bifold panel sizes of up to 1.2m wide and 3m high. This is one outstanding door for aesthetics and design and well worth checking out.

The frameless folding sliding Door.

It is worth giving a mention to the frameless bifolding door. These are minimal-framed slide, stack and fold products that, chosen correctly, provide even thinner sightlines.  If you want even less visible aluminium, then check out frameless bifolding doors.  Sunseeker doors have a mullion sightline of 38mm using a plant-on profile to cover the glass edges.

Frameless Glass Curtains by FGC of Chatham has no visible mullion and only a minimal gasket sight line where the door panels meet. Smart engineering, a patented glass spacer bar and sophisticated gaskets make these doors incredibly thin. Therefore, if you want as much glass as is possible on a bifolding door, we suggest you consider these.  A different kind of bifold in design and operation but also a contender amongst the slimmest bifolding doors.

If you are wondering why some well-known big retail brands are missing, this is because many use the above systems or variations of them. This includes well known retail companies such as:

• Express Bifolding Doors using Schuco, Alumil and Smart Systems
• Bifold Direct
• Everest Home Improvements
• Anglian Home Improvements
• Kloeber using Schuco
• Duration Windows using Smart Systems and Aluk

Are the slimmest bifolding doors better?

No, but the truth is that bifold doors are getting slimmer at the panel junctions. Origin presently hold the top spot for a non-bonded system, but the Sunflex, Schuco and Alumil bifolds are more sophisticated in their design, engineering and technical capability.

AluK Optio BSC94, Smart Systems Visofold 1000 and the Alutech/Alunet bifold doors are three brands with excellent sales, and despite their doors not being the slimmest on the market.  

Centor bifolding doors are probably the best on the market. Yet these aren’t the slimmest either.

Ultimately a buyer and a manufacturer of bifolding doors takes many different factors into account and not just the bifolding door sightline.  However, with the bifolding door market established and with more than 30 systems available, customers have never had more choice.

What to consider when buying standard or the slimmest bifolding doors.

The sightline is just one consideration when buying a bifolding door.  It is not just about the slimmest bifolding doors.  Here is what else is more important.

• The overall product aesthetic and how it looks like a complete door not just in one area.
• The more door panels, the less intrusive the mullion can appear.
• The quality of the hardware, locks and bifolding door handles.
• The colour, handle, configurations available and other personalisation options.
• The security and weather performance of the product.
• The U-Values provided if energy efficiency is important to you.
• The guarantee available with the product.
• Your confidence in dealing with the company providing you with the doors.

If you’re also considering sliding doors, take a look at who makes the slimmest sliding doors in aluminium.

Every year the Door and Window Experts Website helps thousands of homeowners and the trade find the best products from the proper suppliers. A free service, contact us today for details of the slimmest bifold doors near you, trade suppliers on these or any other windows and doors in aluminium.