Once you've decided you want a bifold door, the next question is how many panels it should have. It's a decision most buyers don't think about until they're mid-way through configuring their order, but it makes a real difference to how the doors look, how they open, how much you can see through them when closed, and how much they cost.
This guide walks through the practical trade-offs of 2, 3, 4, 5, and 6-panel bifold configurations, when each makes sense, and the questions worth thinking through before you commit.
The short answer
The number of panels is mostly determined by the width of your opening, but there's flexibility in the middle. As a rough guide:
Opening width | Typical configurations |
|---|---|
1.8–2.4m | 2 or 3 panels |
2.4–3.2m | 3 panels |
3.2–4.0m | 3 or 4 panels |
4.0–4.8m | 4 or 5 panels |
4.8–5.4m | 5 panels |
5.4–6.0m | 5 or 6 panels |
Beyond 6 metres you're into bespoke territory, and beyond 6 panels the mechanics start to compromise on smoothness of operation.
What actually determines the panel count?
Three things.
The width of your opening. Each panel is typically 600–1,000mm wide once you factor in the frame — narrower and the doors feel cramped, wider and the individual panel becomes heavy enough to strain the hinges over time. Manufacturers optimise around 800–950mm per panel for a good balance of glass area and running smoothness.
Whether you want a traffic door. A traffic door is one panel that operates independently, like a normal hinged door, without folding the rest of the set. It's useful for everyday in-and-out — nipping into the garden without folding the whole run open. If you want one, it typically sits at one end of the set and consumes one panel of your budget.
Which way the doors stack when open. Bifolds fold and stack against the jamb at one or both ends of the opening. The number of panels affects how far into your room (or outside) the folded stack projects. More panels = a thicker stack of folded doors, which needs more space to accommodate.
Panel-by-panel breakdown
2 panels
The smallest bifold configuration. Two doors that fold together against one jamb. Ideal for smaller openings — typically 1.8–2.4 metres wide — replacing a set of French doors or a single patio door.
Advantages: cheapest option, folds neatly into a small space, quick to open and close. Disadvantages: one hinged joint in the middle when closed, which is more visually noticeable on smaller openings than on larger sets where the joints are more evenly spaced. Not usually available with a traffic door — the whole set has to open together.
Best for: rear elevations of terraced houses, small kitchens, side returns.
3 panels
The most popular configuration in the UK. Three doors, typically folding all in one direction against one jamb. Standard for openings 2.4–3.2 metres wide.
Advantages: strong balance of glass area and open-plan effect, works with a traffic door (usually the panel nearest the master hinge), folds into a compact stack. Two hinged joints when closed but the proportions are visually balanced. Disadvantages: on wider openings (say 3.2m+), the individual panels become larger and heavier, and you may prefer the more even spread of a 4-panel option.
Best for: standard kitchen extensions, most rear-elevation replacements, garden rooms.
4 panels
Four doors, usually folding in a "2+2" pattern (two panels stacking one way, two the other), sometimes 3+1 or 4+0 depending on preference. Suitable for openings 3.2–4 metres wide.
Advantages: even panel widths keep individual doors manageable, works well with a traffic door, splits the folded stack across both jambs (in 2+2) which minimises the impact on either side of the opening. Disadvantages: more panels means more hinged joints — three visible seams when closed rather than two. On the 3.2m end of the range, panels can feel a touch narrow.
Best for: larger kitchen extensions, medium-sized orangeries, mid-range garden room openings.
5 panels
Five doors, typically folding 3+2 or 4+1. Standard for openings 4.0–4.8 metres wide.
Advantages: allows a wider opening without individual panels becoming oversized, works with a traffic door, gives a stronger open-plan feel than 4-panel configurations. Disadvantages: four hinged joints when closed, folded stack is deeper on the "3" side, individual panels can start to feel narrow if the opening is under 4.5 metres. More panels means more moving parts to maintain over the door's lifetime.
Best for: large kitchen extensions, wraparound extensions, generous rear elevations.
6 panels
Six doors, typically folding 3+3 for symmetry. The largest standard configuration, for openings 4.8–6 metres wide.
Advantages: dramatic open-plan effect, symmetrical stack on both sides, maximum glass area. Disadvantages: more expensive, five visible hinged joints when closed, folded stacks project further into or out of the room. Requires a properly engineered lintel and structural opening — the total weight of six aluminium panels is significant.
Best for: high-end extensions, statement architecture, homes where the bifold is the defining feature of the ground floor.
Fold direction — the decision that affects your room layout
Aside from panel count, the other big configuration decision is which direction the doors fold. Three main options:
All one direction. Every panel stacks against a single jamb. Simple, cheapest to specify, and gives you a completely unobstructed opening on the "clear" side. Downside: the folded stack projects further into the room (or outside) than a split configuration.
Split even (2+2, 3+3). Panels stack on both sides. The folded stacks are smaller and more balanced, but you never get a fully clear side. Good for openings where furniture or a garden feature sits close to one jamb.
Split uneven (3+1, 4+1, 4+2). Most panels stack one way, one or two the other. Useful when you want a traffic door on one side but the bulk of the fold stacking on the other.
Ask your fitter or manufacturer to show you a plan drawing before you commit — configurations always sound clearer on paper than in your head.
Traffic doors: worth it, or not?
A traffic door adds convenience for everyday use — you don't need to unlock and fold the whole set every time you step into the garden. In most households where the bifold is used daily rather than seasonally, it pays for itself in months of hassle avoided.
Some things to know:
The traffic door is always at one end of the set, next to the master hinge
It operates independently, with its own handle and lock
It doesn't cost extra as a configuration option — it just changes which panel is doing what
It's not available on 2-panel sets — those doors always have to fold together
If you're not sure, imagine yourself using the doors in mid-October when it's cold enough that you don't want to fold everything back but you still want to nip outside. That's the traffic door working.
The panel width sweet spot
This is a detail that doesn't usually appear in brochures but matters for how the finished doors feel. Panel width is calculated as your total opening width divided by the number of panels, minus the frame allowance.
Below 700mm per panel: individual doors feel narrow and cramped. Opening feels choppy.
700–900mm per panel: the sweet spot. Doors feel proportioned, hinges glide, glass looks generous.
900–1,000mm per panel: wide panels, dramatic glass, but individual doors become heavy — expect slightly more effort to open and slightly more strain on the running gear over time.
Above 1,000mm per panel: possible but not recommended for domestic use. Better to add a panel.
If your opening is on the boundary between two panel counts, the panel-width calculation is a good tiebreaker.
What the panel count costs
Each additional panel adds around £400–£800 to a standard aluminium bifold in 2026, depending on colour, glass spec, and manufacturer. That's not just the extra door — it's the additional running gear, extra hinges, extra glass, and more complex assembly.
As a rough guide, based on standard direct-from-manufacturer aluminium bifold prices:
Configuration | Typical price range (ex VAT) |
|---|---|
2 panels | £1,600 – £2,600 |
3 panels | £1,900 – £3,500 |
4 panels | £2,600 – £4,500 |
5 panels | £3,200 – £5,800 |
6 panels | £4,000 – £7,500 |
Wider openings with more panels sit at the higher end, along with premium colours and enhanced glass specs. See our full bifold doors cost guide for the detail.
Questions to think through before you decide
Five things worth working through with your builder or fitter before committing to a configuration:
How wide is the finished opening going to be? Not the current opening — the one you'll actually have after any structural work. Get this from the plans, not the guess.
Are you willing to adjust the brickwork slightly to hit a standard size? Standard-size bifolds are cheaper and faster to manufacture than bespoke ones. If your opening is 3.05m, ask your builder whether you can settle at 3.00m — often the answer is yes.
Which way do you want the doors to fold? Consider where your furniture sits, where the sun comes in, and whether the fold direction affects garden access.
Do you want a traffic door? If in doubt, yes. It's the single most useful configuration decision for day-to-day life.
How often will the whole set actually be folded open? For most UK homeowners, the answer is a handful of times a year — mainly summer weekends. That's not a reason not to have bifolds, but it does mean the day-to-day experience is mostly about the traffic door and the view when closed. Configure accordingly.
Common questions
Can I have an odd number of panels that don't fold symmetrically?
Yes. 3-panel, 5-panel, and 7-panel configurations all fold to one side (usually 3+0, 5+0, or 4+3), which some homeowners actually prefer because it maximises the clear side of the opening.
Can panels fold outwards instead of inwards?
Yes. Most manufacturers offer both open-in and open-out configurations at no additional cost. Open-out is more common because it keeps the interior floor clear when the doors are folded back.
Do more panels mean weaker security?
No. Multi-point locking is deployed across every panel in the set — more panels means more bolts, more locking points, and more security overall. All Supafold doors are PAS 24 compliant regardless of panel count.
Can I mix panel widths?
In most cases no — panels are equal-width for structural and aesthetic reasons. Some manufacturers offer bespoke configurations with a wider traffic door and narrower folding panels, but it's unusual and adds cost.
What if my opening is between standard sizes?
Adjust the brickwork if possible (cheapest option), or go bespoke. Bespoke sizes typically add 15–25% to the price and 1–2 weeks to the lead time.
How much space does the folded stack take up?
Rule of thumb: each folded panel occupies about 100–120mm of depth. A 3-panel stack projects roughly 300–360mm; a 6-panel stack (3+3) projects about the same on each side.
Ready to configure your bifold?
Our online configurator walks you through size, panel count, colour, and threshold in under two minutes — with the price updating as you go. Every configuration is manufactured at our Derbyshire factory with a 10-year guarantee.