What Are Bifold Doors?
- 17 July 2026
- News
Choosing new doors is an important decision for any homeowner.
The right doors can improve how your home looks, feels and works every day. They can bring in more natural light, provide better access to your garden and help your living spaces feel larger and more open.
If you are asking what are bifold doors, they are made from several connected panels that fold neatly to the side. This allows them to open up a much wider area than many traditional patio or French doors.
Bifold doors are often installed across the back of kitchens, dining rooms, extensions and conservatories. They can also be used inside the home to divide rooms while keeping the layout flexible.
In this guide, we will explain what bifold doors are, how they work, whether they are secure and what you should consider before installing them.
Having spent over 20 years specialising in windows, conservatories and doors in Milton Keynes, Crown Windows can help you find a stylish and practical design for your property.
What Are Bifold Doors? Your Complete Homeowner’s Guide
Bifold doors are designed to offer natural light, flexible access and a clearer connection between your home and garden.
Unlike standard hinged doors, bifold doors do not need a large area to swing open. Unlike many sliding patio doors, they can also open most of the available doorway rather than leaving one panel in place.
One of the main reasons homeowners choose bifold doors is the sense of space they create. Their large glazed panels can make a room feel brighter when the doors are closed, while the folding design creates a wide entrance when they are open.
However, there is more to consider than appearance alone.
The number of panels, direction of opening, glazing, frame colour, threshold and locking system will all affect how the doors look and work.
In this guide to bifold doors, we will cover:
- What is a bifold door?
- What are the benefits of bifold doors?
- Planning your bifold door installation
- Do I need planning permission for bifold doors?
- Are bifold doors secure?
- How to open bifold doors
- How much are bifold doors?
- How to measure for bifold doors
- Bifold door ideas for different homes
This will help you understand whether bifold doors are the right choice for your property, lifestyle and long-term home improvement plans.
If you are already exploring new doors in Milton Keynes or planning a wider renovation, bifold doors are well worth considering.
What Is A Bifold Door?
A bifold door is made from two or more panels connected by hinges. These panels move along a fitted track and fold against one another as the doors open, creating a concertina-style effect.
Unlike sliding patio doors, where one or more panels usually remain across part of the opening, bifold doors can stack neatly at one or both sides. This creates a wider and clearer entrance between your home and garden.
External bifold doors normally include large areas of glass within slim but strong frames. This can provide wide garden views and allow more natural light into kitchens, dining rooms, extensions and conservatories.
- Between a kitchen and garden
- Across the back of a dining room
- Between a conservatory and garden
- In place of patio or French doors
- Between two internal rooms
Depending on the design, bifold doors may include inward or outward-opening panels, a standard or low threshold, energy-efficient double glazing and a choice of frame colours and finishes.
Many systems also include a traffic door. This is a single panel that opens like a standard hinged door, so you do not need to fold the full set every time you want to enter the garden. This can be especially useful during colder weather or when you only need quick access outside.
At Crown Windows, bifold doors are made to measure. This helps ensure the frame fits the opening correctly and the panels open, close and lock smoothly.
Benefits Of Bifold Doors
Bifold doors offer a wide range of benefits for homeowners.
They are bright, flexible and available in several layouts, colours and finishes. This makes them suitable for both modern properties and more traditional homes.
More Natural Light
One of the biggest benefits of bifold doors is the amount of natural light they can bring into a room.
Large glazed panels can replace a solid wall or smaller doorway, helping daylight reach further into kitchens, living rooms and dining spaces.
This can make a room feel:
- Brighter
- Larger
- More welcoming
- Better connected to the garden
The benefits of the glass can still be enjoyed when the doors are closed, making bifold doors useful throughout the year.
Wider Garden Access
Bifold doors can open a large section of the back of a home.
This creates a wider route between the house and garden, which can be helpful when entertaining guests, serving food outside or supervising children.
During warmer weather, opening the full set can help the patio or garden feel like an extension of the indoor living area.
Flexible Opening Options
You do not always have to open every panel.
Depending on your chosen layout, you may be able to open a single traffic door for everyday access or fold back the full system when you want a wider entrance.
The panels can also be designed to fold towards one side or split between both sides of the opening.
Clear Garden Views
Even when bifold doors are closed, their large glazed areas can provide a wide and attractive view of the garden.
This can be especially useful in kitchens, dining rooms and conservatories where homeowners want to make the most of their outdoor surroundings.
A Modern Appearance
Bifold doors are known for their simple and modern appearance.
Slim frames and large areas of glass can help create a clean finish that works well with open-plan interiors, extensions and renovated homes.
However, they are not only suitable for modern properties. With the right frame colour and panel design, bifold doors can also complement cottages, traditional family homes and period-style buildings.
Made-To-Measure Designs
Every home is different, which is why made-to-measure doors are important.
The panel number, opening direction, frame colour and threshold can all be selected around the property and the way the doors will be used.
Crown Windows provides a free consultation and 3D design plan, helping homeowners see how their chosen design could look before installation begins.
Planning Your Bifold Door Installation
Installing bifold doors can involve more than simply replacing an existing door.
If the opening is being widened, part of the wall may need to be removed. The remaining structure must then be properly supported, which may require a suitable beam above the doors.
Other factors to consider include:
- Indoor and outdoor floor levels
- Drainage around the threshold
- he direction the panels will open
- Space for the folded panels
- Existing radiators or furniture
- Curtains, blinds and other fittings
- Access to the installation area
Planning these details early can help prevent problems and ensure the finished doors work well within the room.
Do I Need Planning Permission For Bifold Doors?
In many cases, you will not need planning permission to replace existing patio or French doors with bifold doors.
Replacing doors within the same opening is often treated as a normal home improvement. However, the rules can depend on the property and the amount of work involved.
You may need to make further checks if:
- You are creating a completely new opening
- The existing opening is being made much wider
- The doors form part of a new extension
- Your property is listed
- Your home is in a conservation area
- The building is a flat or maisonette
- Previous planning conditions affect the property
The Planning Portal’s guidance on doors and windows provides helpful information about when planning permission may be required.
Planning permission and Building Regulations are separate.
Even when planning permission is not needed, the installation may still need to meet Building Regulations covering:
- Structural safety
- Energy efficiency
- Safety glazing
- Ventilation
- Access and thresholds
Homeowners can find further information through the UK Government’s guidance on Building Regulations approval
If a wall opening is being made wider, a structural engineer or another qualified professional may need to check how the building will be supported.
Crown Windows is a FENSA-registered installer. This means eligible replacement door and window installations can be completed and certified in line with the relevant requirements.
Our experienced team can also help explain what may need to be considered before your project begins.
Are Bifold Doors Secure?
Security is an important consideration when installing any external door.
Because bifold doors contain large glazed areas and several connected panels, some homeowners worry they may be easier to enter than a standard back door.
However, modern bifold doors can include strong frames, reliable locking systems and safety glazing designed to protect the property.
High-quality bifold doors can provide a strong level of security when they are manufactured and fitted correctly.
Many modern systems use multi-point locking. This means the door is secured to the frame at several points instead of relying on one lock.
Security features may include:
- Multi-point locking systems
- Strong frames and hinges
- Toughened or laminated glass
- Secure locking cylinders
- Strong handles
- Concealed running equipment
- Anti-lift systems
Anti-lift features help keep the panels securely attached to the track, making them more difficult to lift or remove from outside.
The type of glass is also important. Toughened safety glass is designed to break into smaller pieces rather than sharp sections, while laminated glass can offer additional resistance because it contains an internal layer.
The police-backed Secured by Design initiative provides further information about security standards for windows and doors.
The overall security of bifold doors depends on the full system.
A strong lock should be supported by a reliable frame, suitable glass and professional installation. If the doors are uneven or leave gaps around the frame, they may not close or lock correctly.
At Crown Windows, our experienced fitting teams carefully position and adjust every installation. We can also talk you through the available locking, glazing and security options during your consultation.
How To Open Bifold Doors
Although the exact process can vary, most external bifold doors are opened in a similar way.
To open bifold doors:
- Unlock the main door using the key.
- Move the handle into the open position.
- Open the traffic door if the system includes one.
- Release any additional handles or panel locks.
- Gently guide the connected panels along the track.
- Allow the panels to fold together at the side.
- You should not need to use a large amount of force.
When bifold doors are fitted and adjusted correctly, the panels should move smoothly along the track.
Always keep fingers away from the spaces between the panels while they are folding. Young children should also be supervised when the doors are being opened or closed.
To keep the doors moving properly, regularly clear the lower track of:
- Leaves
- Stones
- Mud
- Food crumbs
- Pet hair
- General dirt
If the doors become stiff, do not force them. First, check whether anything is blocking the track.
If the problem continues, contact the installer rather than trying to remove or adjust the panels yourself.
All Crown Windows installations come with a comprehensive 10-year warranty and an insurance-backed guarantee, giving homeowners added peace of mind after the work has been completed.
How Much Are Bifold Doors?
The cost of bifold doors can vary widely.
There is no single price because every property, opening and door design is different.
A smaller set of bifold doors fitted into an existing doorway may require less work than a wide system that involves removing brickwork and adding structural support.
The final cost of bifold doors can depend on:
- The width and height of the opening
- The number of panels
- The frame material
- The glazing specification
- The chosen colour
- The hardware and handles
- The type of threshold
- Whether a traffic door is included
- Structural work
- Installation access
The quality of the product should also be considered.
Bifold doors contain several moving parts, including rollers, tracks, hinges, handles and locking systems. These components need to work together so the doors can move smoothly and close securely.
The glazing and seals should also help protect the room from cold draughts and poor weather.
The Energy Saving Trust’s guide to energy-efficient windows and doors explains how suitable glazing and well-installed products can help reduce heat loss.
Although general online prices may be useful for early research, they may not include preparation work, structural changes or installation.
For an accurate figure, it is best to arrange a professional survey and quotation.
At Crown Windows, homeowners can request a free consultation and personalised quote. Our team will review the space, discuss your preferred design and explain the available options without relying on a one-size-fits-all price.
You can also receive a free 3D design plan to help you picture the final appearance of the doors.
Measuring For Bifold Doors
Accurate measurements are essential for bifold doors.
If the frame does not fit the opening correctly, the panels may become difficult to move, fail to close securely or leave unwanted gaps.
Basic measurements can help during the early planning stage, but the final survey should always be completed by an experienced installer.
To get a general idea of the size, measure the width of the opening in three places:
- Across the top
- Across the middle
- Across the bottom
You should then measure the height:
- On the left
- In the centre
- On the right
Walls and floors are not always completely straight, so the measurements may vary slightly.
The smallest width and height figures are normally used as the starting point when assessing the opening.
You can also measure diagonally:
- From the top-left corner to the bottom-right
- From the top-right corner to the bottom-left
If these measurements are different, the opening may not be completely square.
However, professional bifold door measurements involve more than the visible width and height.
An installer may also need to check:
- The condition of the surrounding walls
- Floor levels
- The threshold position
- Fitting tolerances
- Drainage requirements
- The structure above the opening
- Indoor and outdoor floor finishes
- The direction the panels will fold
Different door systems may require different allowances. For this reason, homeowners should avoid ordering made-to-measure doors based only on their own figures.
Crown Windows carries out a detailed survey before the doors are manufactured, helping ensure the finished system fits accurately and works reliably.
Bifold Door Ideas For Different Homes
Bifold doors are available in a wide range of styles.
The right design will depend on your property, the available opening and how you plan to use the room.
You should consider the number of panels, colour, glazing and opening direction together rather than making each choice separately.
There are many ways to use bifold doors within modern and traditional properties.
Open Up A Kitchen And Garden
Installing bifold doors across the back of a kitchen can create a bright and practical family space.
When the doors are open, people can move more easily between the kitchen, patio and garden. When they are closed, the wide glass panels can still provide clear outdoor views.
This layout can be ideal for:
- Family meals
- Summer gatherings
- Entertaining guests
- Watching children in the garden
- Creating a brighter kitchen
Connect A Dining Room To The Patio
Bifold doors can create a wider opening between a dining room and outside seating area.
Using similar colours for the indoor flooring and outdoor paving can help the two areas feel more connected.
A lower threshold may also create a smoother visual change between the spaces, although drainage and weather protection must still be considered.
Add Bifold Doors To A Conservatory
Bifold doors can be installed between a conservatory and garden or between the conservatory and the main property.
Homeowners considering conservatories in Milton Keynes can discuss how the doors, glazing, roof and room layout will work together.
The right arrangement can help the conservatory feel like a natural extension of the home.
Choose A Colour That Suits Your Property
Darker frames can create a bold and modern appearance.
Anthracite grey and black are often used on contemporary properties, extensions and homes with light render.
White, cream and softer neutral shades may be better suited to traditional properties, brick homes and cottages.
You could match the bifold doors to your existing windows or choose a contrasting colour to create a stronger feature.
Include A Traffic Door
A traffic door can make the bifold system easier to use every day.
Instead of folding every panel, you can open one door when you need to let a pet outside, take out the rubbish or quickly enter the garden.
Think carefully about which side of the opening will offer the most convenient access.
Use Bifold Doors Inside The Home
Bifold doors do not have to be installed externally.
Internal bifold doors can be used to:
- Divide a kitchen and living room
- Create a separate dining area
- Close off a home office
- Separate a playroom
- Create a flexible guest space
They can be closed when privacy is needed and folded away when you want the rooms to feel like one larger area.
Keeping Your Home Comfortable
As bifold doors contain large areas of glass, energy efficiency is an important consideration.
Modern systems can include insulated frames, energy-efficient double glazing and weather seals that help reduce heat loss.
These features can help keep the room warmer during winter and reduce cold draughts around the doors.
Good glazing may also reduce some outside noise, which can be useful for properties close to busy roads or built-up areas.
Homeowners exploring double glazing in Milton Keynes should consider the performance of the complete system, including:
- The glass
- The frame
- The seals
- The threshold
- The quality of the installation
Even a well-made door may not perform correctly if gaps are left around the frame or the panels are not properly adjusted.
Crown Windows uses experienced fitting teams who install each product carefully and in line with the relevant requirements.
For more inspiration, explore how aluminium bifold doors can transform contemporary homes and create a wider connection between indoor and outdoor living spaces.
Open Up Your Home With Bifold Doors From Crown Windows
Bifold doors are a stylish and practical choice for homeowners who want to bring more natural light into their property and improve access to the garden.
They offer wide glazed panels, flexible opening options and a modern appearance that can suit kitchens, dining rooms, extensions and conservatories.
The right bifold doors can make your home feel brighter, more spacious and better connected to the outdoors.
However, choosing the right product is only part of the process. Accurate measurements, suitable glazing, strong security features and professional installation are all important for long-term performance.
At Crown Windows, we have more than 20 years of experience helping homeowners across Milton Keynes and the surrounding areas improve their properties with made-to-measure windows, doors and conservatories.
From your first design ideas through to installation and aftercare, our friendly team is here to help every step of the way.
Our service includes:
- A free consultation and quote
- A free 3D design plan
- Made-to-measure bifold doors
- Experienced FENSA-registered fitters
- A comprehensive 10-year warranty
- An insurance-backed guarantee
- Friendly and reliable aftercare
Whether you are replacing old patio doors, upgrading a conservatory or creating a wider garden entrance, Crown Windows can help you choose a design that works for your property and lifestyle.
If you are considering bifold doors or new doors in Milton Keynes , get in touch with Crown Windows today to book your free consultation and start planning your home improvement project.
