Coastal Windows, Doors & Conservatories
Home Trade Benefits Products Trade Accounts About Contact Call 01745 338882 info@coastalnw.co.uk Apply for Trade Account
Aluminium Systems

Aluminium Bifold Door Sizes & Configurations

How many panels, how wide, and what to consider when specifying a Smart Visofold 1000 Slim bifold set — the system behind our aluminium bifold doors range.

122mm Slim SightlinesPAS 24 Security TestedFolds In or Out
Aluminium bifold doors folded open onto a patio

Our core bifold system is Smart's Visofold 1000 Slim — the UK's most popular bifold range — and getting the panel configuration right is the single biggest decision when specifying one. Here's what the system offers and how to think through the layout.

The system: Visofold 1000 Slim

FeatureVisofold 1000 Slim
Sightline122mm — 10mm slimmer than the standard bifold door
U-value1.5 W/m²K (1.0 W/m²K centre pane), polyamide thermal break
Frame depth / glazing70mm frame depth, glass up to 28mm
Sash sizeUp to 1.2m wide, 2.5m high, 100kg max per sash
SecurityPAS 24:2016 tested, multi-point locking, shoot-bolts on floating mullions
ThresholdLow or rebated, your choice
ColourStandard, non-standard & dual colour options — see our colours & RAL guide
OpeningFolds internally or externally

Figures as published on our aluminium bifold doors page, cross-checked against Smart's own Visofold 1000 Slim literature.

How many panels do you need?

Bifold sets are commonly supplied from 2 panels up to 7 or more, depending on the total opening width. More panels mean a narrower stack when fully open and finer sightline division when closed; fewer, wider panels mean a bolder look but a bulkier stack.

2–3Compact openings
4–5Standard patio widths
6–7+Wide/multi-bay openings

General trade configuration guidance — exact panel count depends on your opening width and the 1.2m per-sash maximum above.

Traffic doors and everyday access

A "traffic door" (sometimes called an access door) is a single panel within a bifold set, hinged to open independently without folding back the whole run — useful for popping outside without unlocking and stacking every panel. Most bifold sets of 3 panels or more include one, usually at the end of the run nearest the main walkway.

Choosing a configuration

  • Decide which panel needs to be the everyday traffic door, and where it sits in the run.
  • Check whether the doors need to stack against a return wall, or whether a post is needed mid-span for a very wide opening.
  • Choose a low threshold for step-free access, or a rebated threshold for maximum weathertightness — both are available on Visofold 1000 Slim.
  • Confirm your exact opening size with the trade counter before ordering — individual sash limits (1.2m × 2.5m) constrain how a given width can be split into panels.

Frequently asked questions

What's the difference between Visofold 1000 and Visofold 1000 Slim?

Visofold 1000 Slim has a 122mm sightline — about 10mm slimmer than the standard bifold door — using the same polyamide thermal break technology, for a marginally less obtrusive frame when the doors are closed.

What's the maximum size for a single bifold panel?

Individual sashes on the Visofold 1000 Slim system go up to 1.2m wide and 2.5m high. Exact limits for your specific configuration and glazing spec should always be checked against your opening — ask our trade counter for a size check before you order.

Do wide bifold openings need a support post partway across?

Sometimes, depending on the total span, wind loading and structural requirements — check with your installer or a structural engineer for very wide openings before finalising the design.

Can bifold doors be any width?

No — overall width is limited by how many panels you use and each panel's individual size limits. A very wide opening needs either more panels or a structural opening check; it isn't simply a case of scaling up a smaller configuration.

Get a size check before you order

Send us your opening width and height and we’ll confirm a panel configuration that works within Visofold 1000 Slim’s size limits.