All you need to know about sliding patio doors

10 March 2023

If you’re looking for a window and door solution for your home, you’ve probably heard of the galandage bay window. It has become increasingly popular in recent years, thanks to its aesthetic and discreet advantages. But what exactly are they, and what are the advantages of this type of window? In this guide, we’ll tell you all you need to know about the curved bay window, from its advantages to its price, installation and energy efficiency.


What is a bay window?

The galandage bay window is a type of sliding window that opens on a track hidden in the wall. This means that when you open the bay window, the glass panels slide discreetly into the wall, creating an almost invisible opening between your home and garden. In a nutshell, the sliding door disappears into the wall.

As a result, it is composed of two or more glass panels, which slide one behind the other when opened. As they are designed to occupy the entire wall, they are generally larger than the bay windows.


How roller shutters work

The galandage bay window system consists of several glass panels suspended on carriages that slide on a guide rail. The glass panels are attached to the carriages by nylon or steel wheels, allowing them to roll smoothly along the rail. The carriages are held in place by tension springs that ensure smooth, silent window closure.

Manual or automatic opening

The roller shutter system can be operated manually or automatically. In a manual system, the glass panels are moved by pulling on a handle or pull bar attached to the first glass panel. The first glass panel is then pulled outwards, and the subsequent panels move in tandem. In an automatic system, the glass panels are driven by an electric motor activated by a remote control or wall switch.


The advantages of sliding patio doors

The bay window is a popular sliding window option, but what are the advantages over a traditional sliding window? Let’s take a closer look.

01. It lets in more light

Unlike a traditional bay window, a bay window takes up the entire wall. It therefore offers more natural light into the house, and an unobstructed view of the outside.

02. It saves space

As it occupies the entire wall, when open it is completely invisible. The result is a feeling of space and fluidity between your interior and exterior.

03. It’s sleek and stylish

The galandage bay window is aesthetically pleasing, offering an unobstructed view of the outside of the house while creating an almost invisible opening between the inside and outside of the house. Unlike traditional sliding windows, which often have a visible frame around the glass panels, the galandage bay window is designed to be discreet, concealing the glass panels in the wall when open.

What’s more, the bay window can be designed in a variety of materials, such as aluminum or PVC, which can be customized to suit the style of the home.

04. It is secured

Bay windows are designed to be more difficult to break into than traditional sliding windows. In fact, it’s equipped with glass panels held in place by tension springs that create a solid barrier against any break-in attempt.

It is made of tempered or laminated glass, which is more impact-resistant than ordinary glass. Finally, it can be fitted with additional security devices, such as multipoint locks or security bars, to further enhance its security.

05. It’s more insulating

That’s right, a bay window is no less insulating than a traditional bay window. In fact, because of their airtight design, roller shutters are often more insulating than traditional sliding windows.

The bay window is fitted with thermally insulated glazing, designed to reduce heat loss in winter and heat penetration in summer. Thermally insulated glazing consists of two or more panes of glass separated by a layer of air or inert gas, which reduces heat transmission through the window.


  • Cost: sliding patio doors are often more expensive than traditional sliding windows, due to their complex design and more difficult installation.
  • Installation: the installation of a bay window can be more difficult than the installation of a traditional bay window, due to its complex sliding mechanism. Unless you’re a very good do-it-yourselfer, it requires the intervention of a qualified professional to guarantee correct, long-lasting installation.

Glass installation

First of all, this type of window can only be installed as part of a new build or major renovation. Some masonry or carpentry work is required, as a gap must be created in the wall. This space is located between the structural wall and the lining partition.

The professional installation process begins with precise measurements to ensure that the bay window fits perfectly into the wall opening. Next, the technician will remove the old window and prepare the wall opening for installation of the new window.

Once the opening is ready, the bay window can be installed by sliding it into the opening and aligning it with the wall. The glass panels are then attached to the window rails, which are then fastened to the wall.

After installation, the professional will check that the bay window is working properly by sliding it several times to ensure that the sliding mechanism is smooth and silent. Finally, he can install finishing touches, such as baseboards and mouldings, to give the window a clean finish.

Adding shutters to the system

Shutters can be integrated directly into the roller shutter frame, or installed separately. However, it is important to consider the design of the bay window when choosing shutters, as some models may not be compatible with the sliding mechanism of the bay window panels. It is advisable to call in a professional to determine the most appropriate options for your bay window.

The average price of a bay window

Galandage windows are generally more expensive than traditional sliding windows, due to their complex design and more difficult installation. It costs several hundred euros more than a conventional bay.

The average price of a bay window varies from €1,000 to €3,000 or more, depending on the characteristics of the window, the frame material and the type of glazing.


Important criteria to consider when making your choice

  • Glass size: the bay window must be adapted to the size of the wall opening.
  • Material: depending on your budget, the frame material may vary. Aluminum frames are often more expensive but more durable, while PVC frames are more affordable but less durable.
  • Glazing type : thermally insulated glazing offers better thermal insulation, while acoustic glazing offers better acoustic insulation.
  • Price : Since a bay window is more expensive than a traditional glass wall, be sure to set a budget before you start your search to find an option that suits your needs and budget.

The sliding glass door for your veranda or home extension

Installing a bay window in a veranda or house extension offers a number of advantages, including natural light, a view of the outside, improved thermal and acoustic insulation, and a unique aesthetic touch. There are also other ways of enclosing your veranda.


veranda sliding bay window

VERANDAIR helps you make the right choice

Discover all the glass wall options and veranda products and models we offer at VERANDAIR. We offer a multitude of options for the construction of verandas, patio roofs and pergolas, to best suit your budget and taste. We also deliver and install your sliding glass door, which, like all our products, comes with a 15-year warranty. Don’t hesitate to opt for one of our modular solutions!

New VERANDAIR® brochure

Do you have a pergola and want to add a bay window?

Download our brochure and discover our range of sliding glass walls. Find out more about our projects and our tips for choosing the right sliding door!

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