Bifold Doors (UK Guide 2025)
Prices, Sizes & Styles
Bifold doors are one of the most popular ways to open a kitchen, dining room or orangery straight out onto the garden. Multiple panels fold neatly to one side, creating a wide, uninterrupted opening and a strong inside–outside feel.
This guide explains what a bifold door is, how it differs from French and sliding doors, the main design choices, aluminium vs uPVC, prices, security, energy performance, pros and cons, and how to compare quotes confidently.
Table of Contents
What is a bifold door?
A bifold door is made up of several glazed panels that are hinged together. As you open the door, the panels slide and fold along a track, stacking neatly at one or both ends of the opening.
Compared with a standard patio slider or set of French doors:
You can usually open a much wider clear span, which is ideal for entertaining and summer use.
The stacked panels sit mostly inside or outside the opening, so they need clear space to park.
You can add a “traffic” door that works like a normal hinged door for everyday use.
Bifold doors work particularly well:
across the back wall of a kitchen–diner
between a house and an orangery or conservatory
in garden rooms and home offices
on large balconies and roof terraces (with the right balustrades and thresholds)
Key design choices
Panel numbers and sizes
Most domestic bifolds have between 2 and 7 panels. More panels give a wider opening but mean more vertical frame lines.
Typical panel widths sit between 700 mm and 1,000 mm. Wider panels mean fewer frames and more glass; narrower panels are easier to handle and stack.
Think about:
total opening width
whether you want panels to stack all to one side or split (e.g. 3 + 3)
how the panels will affect furniture and walking routes when they’re open
Your installer should confirm what sizes their system allows and how much structural support your opening will need.
Opening direction and traffic door
You’ll choose whether the doors open inwards or outwards and which side they stack to.
Most UK homeowners pick outward-opening bifolds, so the stacked panels sit on the patio rather than in the room.
A traffic door (or “access sash”) is a single panel that can open independently for everyday use, so you don’t have to slide and fold the whole set to nip in and out. It’s very handy near a kitchen or utility room.
Threshold options
The threshold affects accessibility, weather performance and how “flush” the transition is.
Standard rebated threshold
– Slight step, but excellent weather resistance.Low or flush threshold
– More seamless connection to the patio and easier wheelchair access.
– Needs careful detailing to manage water and meet Part M (access) and Part C (moisture) of the Building Regulations.
If you’re planning a flush finish, discuss drainage channels, falls and flooring build-up early with your installer and builder.
Glazing and energy performance
Glazing has a big impact on comfort and running costs. For most UK homes in 2025 you’ll be looking at:
Double glazing with soft-coat low-E glass and warm-edge spacers as standard
Argon-filled units for better insulation
Optional triple glazing on north-facing or very exposed locations
Ask for:
Whole-door U-values (not just the glass) that meet or beat current Part L requirements
Solar-control options if the doors face south or west and the room already gets very warm
Our Double Glazing Cost Calculator can help you benchmark prices for different glazing upgrades.
Colours, finishes and styles
Aluminium bifolds come in a wide colour range, often with:
classic white, black or anthracite grey
dual-colour options (e.g. grey outside, white inside)
textured and metallic finishes
uPVC bifolds are usually more limited in colour but can still offer popular greys and woodgrain foils.
Think about:
matching or contrasting your uPVC windows and uPVC doors
how dark colours might affect heat build-up in full sun
whether you prefer slim modern lines or chunkier, more traditional framing
Hardware and handles
Details matter with bifold doors. Look at:
handle styles and colours
how easy the locks are to operate
whether the rollers feel smooth and robust
the quality of the hinges and gaskets
Better hardware usually means less adjustment over time.
Aluminium vs uPVC bifold doors
Aluminium bifolds
Aluminium is the most common material for bifold doors in the UK. Advantages include:
Slim sightlines – more glass, less frame
Strength – allows wide spans and tall panels without excessive flex
Colour choice – hundreds of powder-coated RAL colours and dual-colour options
Stability – minimal expansion and contraction, so doors stay aligned more easily
Well-designed aluminium bifolds now include thermally broken profiles, modern gaskets and high-performance glazing, so they can achieve low U-values while feeling solid and secure.
They usually cost more than uPVC, but many homeowners see them as a long-term upgrade, especially on large openings.
uPVC bifolds
uPVC bifolds can work well on smaller spans and where budget is tight. They offer:
good insulation
lower initial cost
simple white or foiled finishes to match uPVC windows
However, uPVC frames are bulkier and more flexible than aluminium. On very wide spans or in hot, sunny locations that movement can make fine adjustment more important. For big openings or very frequent use, aluminium is usually the safer long-term choice.
Timber and composite options (briefly)
You’ll also find timber and composite bifolds, often in higher-end projects. They can look beautiful but usually require more maintenance, careful finishing and a higher budget.
Which material should you choose?
As a rule of thumb:
Choose aluminium if you want slim sightlines, large spans, bold colours and long-term stability.
Choose uPVC if you’re working to a tighter budget and want to match existing uPVC frames on a modest opening.
Consider timber or composite only if you’re prepared for the extra cost and upkeep.
If you’re unsure, our quote system can collect both aluminium and uPVC bifold prices so you can compare value, styles and energy ratings side by side.
Security and certification
Because bifold doors create such a large opening, security is a key concern. Modern systems can be very secure when they combine:
Multi-point locking on the main traffic door and intermediate panels
Top and bottom shootbolts that lock each panel securely into the track
Internally beaded glazing, so glass can’t be popped out from outside
Reinforced frames and locking points
Laminated or toughened glass in the bigger panes
When you compare quotes, look for:
PAS 24: indicates the door set has passed enhanced security tests for resistance to attack.
Secured by Design (SBD): a police-backed initiative; SBD-accredited bifolds meet higher design and security standards.
TS 007 / SS 312 rating on cylinders: for doors with accessible locks, a 3-star cylinder or a 1-star cylinder with 2-star handle provides strong anti-snap, anti-drill protection.
Correct installation matters as much as the product. The frame must be fixed into sound structure, with the right packers and fixings, so that locks engage cleanly without strain.
Energy efficiency, comfort and weather performance
Large glazed areas can either make a room feel amazing or uncomfortably hot or cold. For comfortable, efficient bifolds, pay attention to:
Whole-door U-value – lower numbers mean better insulation. Ask each installer for this figure, not just the glass U-value.
G-value / solar gain – some glass lets in more solar heat than others. Solar-control glass can reduce overheating in south- and west-facing rooms.
Weather seals and gaskets – look for continuous seals around each panel and between panels, not gaps at the corners.
Trickle vents – may be required to satisfy ventilation rules when replacing existing external doors.
A good system, properly fitted, should feel snug in winter and free from noticeable draughts, even on windy days.
Typical UK bifold door prices in 2025
Prices vary by material, size, configuration, glazing and installation complexity, but as a broad guide for fully fitted bifolds in 2025:
Aluminium bifold doors
3 panels (approx. 3.0 m wide): from around £4,000–£6,000
4–5 panels (approx. 4.0–5.0 m): from £5,500–£8,500+
uPVC bifold doors
3 panels: from roughly £2,500–£4,000
4–5 panels: from £3,500–£6,000+
Upgrades such as triple glazing, special colours, low thresholds and integrated blinds will add to these figures.
For a deeper dive into how prices change with panel count and material, see our dedicated bifold door cost per panel guide on the blog, and use our Double Glazing Cost Calculator to sanity-check quotes.
Planning rules, building regulations and structure
In many cases you can replace an existing patio door with bifolds under permitted development, provided you’re not making major structural changes or altering the property’s overall appearance dramatically.
However, you still need to satisfy Building Regulations, particularly around:
Structure (Part A) – lintels or steels must support the opening safely.
Fire safety (Part B) – especially in kitchens and on upper floors.
Energy efficiency (Part L) – U-values and airtightness.
Access (Part M) – step heights and thresholds.
Glazing safety (Part K) – toughened or laminated glass in critical locations.
Most installers self-certify through bodies such as FENSA or Certass. You should receive a compliance certificate after installation, which you’ll need if you sell the property.
Installation, maintenance and lifespan
Professional installation
Because bifolds rely on precise alignment and smooth running gear, professional installation is strongly recommended. A good installer will:
survey the opening accurately
ensure the frame is plumb, level and square
pack and fix the frame securely into solid structure
set up the rollers, hinges and locks for effortless operation
seal the perimeter correctly to keep out water and draughts
This reduces the risk of panels binding, dragging or leaking later.
Maintenance
Bifold doors are relatively low-maintenance, but they do benefit from:
regular cleaning of tracks and drainage slots
a light lubricant on hinges, rollers and lock keeps
checks that fixings and handles stay tight
occasional adjustment if settlement or movement affects alignment
Avoid oil-based sprays on gaskets; use products recommended by the manufacturer.
Expected lifespan
With modern materials and good care, you can expect:
Aluminium bifolds – typically 30+ years
uPVC bifolds – around 20–25 years
Glazing units – often 20–30 years before any misting or degradation
Harsh coastal or exposed locations may shorten these figures slightly; sheltered sites and gentle use may extend them.
When bifold doors are (and are not) a good idea
Great situations for bifolds
Bifold doors are particularly effective when you:
entertain regularly and want a wide opening to the garden
have a generous patio or deck for the panels to stack onto
are building an orangery or extension and can design the structure around them
want to create a dramatic feature wall in a kitchen–diner or living space
Situations where another option may suit better
Sometimes sliding doors or French doors might work better:
In very windy or exposed locations, large bifolds can feel more vulnerable when open.
Where you have limited external space, stacked panels may get in the way.
If you mainly want a uninterrupted view rather than a huge opening, a large slider with very slim frames can be ideal.
Our uPVC Doors and uPVC Windows guides cover these alternatives in more detail.
How Bestpricevalue.com helps you compare bifold door quotes
Choosing bifold doors is a big investment, and offers from different companies can be hard to compare. At Bestpricevalue.com we:
gather a few carefully selected installers that cover your postcode
check their reviews, accreditations and product ranges
ask them to quote on the same basic specification, so it’s easier to compare
highlight where one quote includes extras (or leaves something out)
help you understand U-values, security options and warranties
You stay in control and deal directly with the companies, but you have an independent agency on your side to spot gaps and negotiate when it makes sense.
FAQs
Q1: Are bifold doors draughty or cold in winter?
A: Modern bifold doors with good seals, thermally broken frames and low-E double glazing can feel just as comfortable as a high-quality patio door. Draughts usually come from poor installation or cheap systems with weak gaskets. Ask for the whole-door U-value and choose an installer with strong feedback on weather performance.
Q2: How wide can a bifold door be?
A: Exact limits vary by system, but domestic bifolds commonly span between 2.4 m and 6.0 m. Each panel is most often 0.7–1.0 m wide. Wider openings may need extra structural steelwork or a different design, such as combining bifolds with fixed side lights. Your installer should confirm what their product can safely achieve.
Q3: Do I need planning permission for bifold doors?
A: If you’re simply replacing an existing external door or window with a similar-sized opening, you may not need separate planning permission. Larger structural changes or work on listed buildings and properties in conservation areas can trigger extra rules. Regardless of planning, the work must still comply with Building Regulations, so make sure your installer can self-certify and provide the correct paperwork.
Q4: Which is better for bifolds: aluminium or uPVC?
A: For most wide openings and busy family homes, aluminium is the better choice. It offers slimmer frames, greater strength and better long-term stability. uPVC can work well on smaller spans and tighter budgets, especially where you want to match existing uPVC frames. If in doubt, collect quotes for both and compare how they look, feel and perform.
Q5: Can I retrofit bifold doors into an existing opening?
A: Yes, many bifold installations involve replacing old French doors or sliders. The main questions are whether the existing lintel can carry the load, how much structural adjustment is required and how the new threshold will connect to your internal floor and external patio. A site survey will clarify what’s possible and help you budget for any building work.