The Ultimate Trade Friendly Bifold Door Sizes & Configurations Guide
If you install aluminium doors for a living, you know this already: bifolds are rarely “standard”. Every opening is different. Every customer has a preference. And every job needs to balance looks, budget, and practicality.
At 6 Day Doors, we manufacture high-performance trade bifolds with fast lead times and a wide choice of sizes and configurations. This guide breaks down everything you need to know about bifold door sizes, panel layouts, traffic doors, thresholds, and measuring — in plain English.
Whether you’re pricing a 2-panel set for a small extension or a 6-panel system for a full-width opening, this is your trade-friendly reference.
Why Bifold Door Sizes Matter
The size of a bifold door system affects:
- Structural opening requirements
- Number of panels
- Panel width
- Glass-to-frame ratio
- Cost
- Ease of use
Too many panels can increase frame lines. Too few can make panels too wide and heavy. The goal is to strike the right balance.
Before anything else, you need to confirm two things:
- Structural opening width
- Structural opening height
From there, the panel count falls into place.
Maximum Heights & General Size Rules
All bifold doors from 6 Day Doors can have a maximum height of 2500mm. However, if you need a different height speak to our team, we may be able to help.
Below is a simple size guide based on aperture width:
| Panels | Min Width | Max Width |
| 1 Pane | 600mm | 1200mm |
| 2 Pane | 1200mm | 2400mm |
| 3 Pane | 1800mm | 3600mm |
| 4 Pane | 2400mm | 4800mm |
| 5 Pane | 3000mm | 6000mm |
| 6 Pane | 3600mm | 7200mm |
These are general working ranges. Final specs will depend on profile system, wind loading, and site conditions.
2 Panel Bifold Doors
Best for smaller openings.
A 2 panel bifold door usually suits apertures between 1200mm and 2400mm wide.
Common uses:
- Kitchen extensions
- Rear utility rooms
- Small garden rooms
Often configured as:
- 1 panel folding + 1 traffic door
This gives daily access without fully opening the system.
You can see product examples here:
When to recommend 2 panels:
- Narrow openings
- Budget-sensitive projects
- Where minimal structural change is planned
3 Panel Bifold Doors
A 3 panel bifold door works well between 1800mm and 3600mm wide.
It’s one of the most flexible options.
You can configure it:
- All panels folding one way
- 2 panels one way, 1 panel opposite
- With or without a traffic door
Great for medium-sized extensions.
Still affordable.
Visually balanced.
You can see product examples here:
4 Panel Bifold Doors
Now we’re into full extension territory.
A 4 panel bifold door suits widths from 2400mm to 4800mm.
Popular for:
- Open-plan kitchen diners
- Renovation projects
- New-build garden openings
Typical configurations:
- 2 left / 2 right (centre opening)
- All panels stacking one side
- Traffic door on either end
A centre-opening layout gives a symmetrical look. Many homeowners like this because it feels balanced.
You can see product examples here:
5 Panel Bifold Doors
When the opening gets wider, flexibility increases.
A 5 panel bifold door fits 3000mm to 6000mm wide openings.
You can:
- Split 3 + 2
- Stack all 5 one way
- Include a traffic door
The odd number creates more configuration options. That’s often helpful on awkward layouts.
You can see product examples here:
6 Panel Bifold Doors
For wide-span openings.
A 6 panel bifold door covers 3600mm up to 7200mm.
Common in:
- Full-width rear elevations
- Luxury extensions
- Commercial glazing installs
Typical layout:
- 3 left / 3 right (very popular)
- All stacking one side
This gives maximum opening width when fully folded back.
You can see product examples here:
Open In vs Open Out
Before choosing panel configuration, decide on direction.
Open Out (Most Popular)
Panels fold externally.
Why installers prefer it:
- Preserves internal floor space
- Keeps furniture layout simple
- Creates a smooth indoor–outdoor transition
Most customers choose this option.
Open In
Panels stack inside the room.
When it makes sense:
- Small patios or decking
- Tight garden spaces
- External obstructions
There is no “right” choice. It depends on the property. Always speak to the experts before placing your order to determine the best direction for your property
Choosing Panel Width: Bigger vs Smaller Panels
Panel width affects appearance and cost.
Aesthetics
Fewer, wider panels mean:
- Less aluminium frame
- More visible glass
- Cleaner sightlines
- Better views
This creates a modern look.
Cost
Fewer panels usually reduce:
- Profile costs
- Hardware components
- Manufacturing time
Which can make pricing more competitive.
However…
More Panels = More Flexibility
Extra panels allow:
- More stacking options
- More traffic door placements
- Easier access points
There’s always a trade-off.
What Is a Traffic Door?
A traffic door is the everyday access leaf.
It works like a normal single door without folding the full system.
Why it matters:
- Daily convenience
- Better security control
- Improved ventilation
- Reduced wear on hinges
Most trade installers recommend including one unless the opening is very small.
Threshold & Sill Options
Threshold choice affects both performance and usability.
Low Threshold
- Easier access
- Good for wheelchair use
- Popular in family homes
But may require:
- Careful drainage planning
Weathered Threshold
- Better weather protection
- Slight step up
- Often used in exposed sites
Always check:
- Drainage strategy
- DPC levels
- Finished floor heights
Common Opening Scenarios
Here are typical trade examples.
1800mm Opening
→ 3 panel bifold
2400mm Opening
→ 3 or 4 panel option
3000mm Opening
→ 4 or 5 panel
4800mm Opening
→ 4 panel (wider leaves) or 6 panel (narrower leaves)
Discuss with the client what matters more:
- Larger glass panes
- Or more flexible folding
Measuring Checklist (Trade Use)
Before placing an order, confirm:
- Structural opening width (3 measurements)
- Structural opening height (3 measurements)
- Floor level (internal vs external)
- Lintel type and load
- Plaster allowance
- Tolerance gaps
- Threshold type
- Opening direction
- Traffic door position
- Handle colour
- RAL colour choice
All our products have visual cues to show you exactly what your configuration will look like before you order. Visit our aluminium bifold doors page to see exactly what you are ordering.
Technical documents for the 6 Day Doors bifolds are available here:
Cost Considerations
Panel count affects pricing. So do:
- Glass specification
- Hardware
- Finish
- Threshold type
- Delivery location
If your customer is comparing options, direct them to:
Read our blog on: The Cost of Installing Cheap Doors: Why Install Quality Doors
Final Thoughts
Choosing the right bifold door sizes and panel configuration is about more than width and height. It’s about space, access, cost, and how the doors will be used every day.
- 2 panel bifold doors suit compact openings.
- 3 and 4 panel systems work for most extensions.
- 5 and 6 panel bifold doors are ideal for wide spans and statement projects.
Every job is different. That’s why installers need flexibility.
At 6 Day Doors, we specialise in manufacturing high-performance aluminium bifold doors for the trade, with fast turnaround and a wide choice of configurations. If you need help selecting the right size or layout for your next project, our team is ready to support you.
For pricing, specifications, or trade support, get a quote for bifold doors.
Fast lead times. Reliable trade supply. Built for installers.
