Bi-Folding Doors - Add The Wow Factor To Your Home

bi folding doors

Imagine being able to open up an entire wall of your room, creating space and letting fresh air and natural daylight flood into your home.

Whether you have a bedroom with Juliette balcony, a dining kitchen, a conservatory or an orangery, bi-folding doors can provide a stunning alternative to patio or French doors.

Coastline’s bi-folding doors were the first fully bespoke PVCu bi-folds to be designed, engineered and made in the UK – and we believe they are still the best.

Available in a wide choice of opening configurations and colours, your bi-fold has ultra-slim sightlines, providing your room with a clean, modern appearance.

Safety features include the innovative low threshold option for family friendly and wheelchair use.

What’s more, the Liniar bi-fold offers high energy efficiency, combined with the best security features on the market – bringing you a modern spacesaving solution for your home that will definitely give it the ‘wow’ factor.

2 sets of bi-folding doors

Better for the environment

Energy Efficiency Explained

One of the most effective ways you can save energy within your home is through installing energy efficient windows, doors and roofs.

Liniar frames outperform most of the other leading brands in the UK when it comes to thermal efficiency – mainly due to our innovative PVCu multi-chambered profile design.

The thermal efficiency of a door is measured in U-values, which demonstrate how effective the door is at preventing the transfer of heat into and out of a building.

The lower the U-value, the higher the doors’ effectiveness at keeping the heat inside your home when it’s cold outside.

The standard Liniar bi-folding door range can achieve a U-value of 1.3 W/m2K when fitted with cost effective double glazed units, which means you’ll be able to enjoy a warmer and quieter home as well as lower energy bills.

And for even greater thermal efficiency, the Liniar ModLok bi-folding range can be fitted with triple glazing, reaching an impressive U-value of 1.0 W/m2K

white bi fold doors


Liniar profile is made from 100% lead-free PVCu – better for the environment and better for you and your family. You no longer have lead in your petrol or paint, so why choose to have frames containing lead?

Designed for today’s challenges

The Liniar bi-folding door range is beautifully designed for modern living.

Built to create the perfect summer ambience, it’s equally as important that our doors withstand the worst of the British winter weather.

We’ve rigorously tested our bi-folding doors to make sure they exceed the appropriate British Standards for weather performance.

We also subject our doors to a regime of robot cyclic testing in our purpose-built laboratory, making sure all mechanical parts will stand up to the repeated operation necessary for daily living.

A Grand Design

Bi-folding doors are becoming more popular than ever before, thanks in part to their regular appearance in television home make-over and lifestyle programmes.

Timber or aluminium are often perceived as the only materials that can be used for bi-folding doors, but doors made from lead-free PVCu can actually offer many more benefits:


With Liniar’s foiled woodgrain-effect options, your bi-folding doors can have the appearance of timber, without the need to repaint them each year.

If you choose our flat grey frames, your bi-folding doors will rival the most contemporary aluminium range on the market, keeping your home much warmer at a more cost effective price. And Liniar’s ‘top of the range’ ModLok™ bi-folding door offers even greater strength and rigidity, combining all of the structural benefits of an aluminium door set with the energy efficiency of PVCu.

Discover why more and more people are choosing Liniar’s bi-folding doors to add an extra dimension to their homes.

grey and white bi-folding doors

Your Home, Your Choice

The Liniar range offers complete flexibility, whatever the room or the size of opening you need.

Manufactured in our decorative sculptured profile, Liniar bi-folding doors are available in a wide variety of colours.

With options from two to seven panes, all with our beautiful, super-slim sightlines, you can also choose how many doors fold back to each side of the frame.

The Liniar standard bi-fold door range is available in a wide range of configurations whilst the Liniar ModLok™ bi-folding door range offers an even greater number, due to its additional strength and rigidity.

A brand new concept in locking technology, ModLok™ has been developed by Liniar to enable even wider door configurations.

Combining aluminium reinforcing within the bi-fold doors and frame with a high security locking mechanism, the Liniar ModLok™ bi-fold offers all the structural benefits of an aluminium door set combined with the thermal benefits of PVCu – bringing you the best of both worlds.

Our door pane numbering works like this:

• The first number shows the number of doors in total within the frame.
• The second number shows the majority of doors folding back to either left or right.
• The third number shows the balance of doors opening in the opposite direction.

So, a 4-3-1 bi-folding door would be four panes wide, with three doors folding back to one side of the frame, and a single opening door on the other.

internal bi-folds

ModLok bi-fold configurations

ModLok bi-fold configurations

Standard bi-fold configurations

Standard bi-fold configurations

Designed for living

Liniar’s bi-folding doors are crammed full of innovative design features.

Low maintenance

With a set of Liniar bi-folding doors you can rest assured that you won’t need to spend hours looking after them to maintain their beauty.

Our 10 year frame guarantee gives you the peace of mind that the colours won’t fade – and not only that, you won’t need to treat or paint them each year to keep them in tip top condition.

Just an occasional wipe down with soapy water is all they need to keep them looking their best.

bifold locks

Family friendly

The Registered Design protected Liniar low-threshold option creates a seamless entrance and exit, making it ideal for family homes. An optional tray to seat the low threshold creates an easy-access ramp for wheelchairs and prams.

Ultra-low, the Liniar threshold measures just 24mm at its highest point, with silver or gold finish available to perfectly complement the door hardware.

Strong and Secure

The shootbolt locking mechanism designed into each Liniar bi-folding door ensures the door is bolted firmly into the stainless steel track, maximising your security.Built in anti-lift features, anti-bump cylinders and optional anti-snap cylinders combine to bring you peace of mind.

Liniar’s bi-folding door range is also available with ModLok™, a new concept in locking technology. ModLok™ is a highly innovative combined reinforcing and locking mechanism, bringing additional strength and rigidity to the doors and enabling you to have even wider configurations of bi-folding doors. ModLok™ also offers enhanced security features including 3 opposing hooks and 2 shootbolts built in to every master door, plus 2 anti-lift shootbolts on every slave door.

The Liniar ModLok™ bi-fold offers all the structural benefits of an aluminium door set combined with the thermal benefits of PVCu.


We’ve added slim hinges with the fixings hidden inside, not only maintaining the sleek lines but enhancing security as they can’t be unscrewed from outside.

We wanted to offer a low threshold, without the need for expensive and messy excavation, so we designed our own clever solution.

We’ve even designed folding keys, to avoid any problems with keys being left in the locks during operation – it’s often the small things that make a huge difference.

Uniquely Designed

We’ve taken steps to protect our designs to ensure only our customers get all the benefits that come with choosing Liniar:

Super smooth action

Your bi-folding doors are engineered to give you the reassurance that they won’t bend or warp – whilst the super smooth rolling action makes them feel incredibly light.

Ergonomic handles are built in to each hinged section, making the doors easy and safe to operate for all age groups.

Liniar’s patented roller mechanism is hidden inside each door, maintaining its sleek lines and giving all Liniar doors the most effortless glide action on the market.

Discreet magnets ensure that when the doors are folded back, they will remain securely in place.

And with our ModLok™ range, only the “master” door will open first, so no chance of spraining locks by trying to open the wrong door.

Handles and Hinges

Choose from white, black, chrome or gold handles and hinges to match your home and lifestyle.

Accessories to Suit You

Additional options to consider when choosing your Liniar bi-folding door.

bifold accessories

Personalise your Liniar bi-fold

The Liniar range of bi-folding doors is available in a huge variety of colour options, with additional colours available upon request.

Our wood-grain foils give the authentic appearance of timber without the maintenance, and are precision factory-fitted, so you’d be forgiven for thinking your frames were actually made of wood.

The whole range comes with the Liniar 10-year frame guarantee against fading, cracking or warping.

bifold colours

Contact us to arrange an appointment or telephone our office on 01323 488700.


  • Coastline Windows
  • Unit 14,Chaucer Industrial Estate
  • Polegate, East Sussex
  • BN26 6JF
  • Tel: 01323 488700
  • Fax: 01323 487111


Coastline are professional suppliers of windows, doors and conservatories in Sussex and the South East. We pride ourselves in the quality of our service and product while retaining a competitive pricing policy.

We have one of the widest ranges of Double Glazing in Sussex, providing our customers with a huge selection of options for conservatories, porches, doors and windows in Sussex.

We appreciate that home improvements can be a big step, which is why Coastline believe in ensuring every one of our customers gets the friendly, professional and personal attention that they need to be confident that they are choosing the right products and service for their property.

Contact Coastline today for a no obligation consultation about your plans and find out how we can help with all requirements for conservatories, porches, windows and doors in Sussex.

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"Efficient, courteous and do a great job...."

All in all a very professional company indeed.

Mr and Mrs S, Eastbourne, East Sussex