Manufacturers & Installers of premium Bow and Bay Windows for over 30 years

Here at Spire Window Systems, we offer high quality PVCu bow and bay windows at fantastic competitive prices!
Our innovative bay and bow windows from Liniar come in a variety of styles and provide features and benefits that are unmatched in the market today. Liniar’s popular windows have ultra-thin frames which not only improve the field of view, but also the flow of natural light.
Make your house seem bigger and let in the world’s natural beauty when you install a bow or bay window!

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Bow and Bay Windows

Bay Windows
A bay window is a three-part window that bends outward. Picture windows are in the middle, with different window designs on either side. In most cases, the side windows are of the same type. Typically, bay windows are canted (an angled/oblique line or surface that specifically cuts off a corner) at a 45- or 90-degree angle. Windows often allow light to enter from one perspective. There are three directions from which sunshine might enter your home because bay windows have three sides. A big bay window will automatically light up your house. Bay windows can be viewed as an extension of your home. The extra space that the bay window adds from the house adds more space for you to utilise in different ways. 
Bow Windows

A bow window is arc-shaped window and has at least four windows, most of which are casement windows. They offer all of the advantages of bay windows, including extra room, a variety of uses, excellent lighting, a better view, and enhanced property value. Bow windows are a wonderful choice if you want to expand space, improve the view, increase natural lighting, enhance the appearance of your home, or create a space that will be utilized for a particular purpose, such as seating, a room’s accent, or storage.

When you want additional light, to make the space appear larger than a bay window might, and to have variable window pane sizes, bow windows are a better option than bay windows!

Why Choose Spire Window Systems?

Based in Lincolnshire, Spire Windows have been proudly manufacturing and installing high performance home improvement products for over 40 years. Not only are our products high quality, so are our installers. Here at Spire Windows we expect only the best for our customers and as a family owned business, we strive to offer the fantastic customer care. Our amiable and knowledgeable team members will handle every step of the process and perform the work to the highest standards, from design to survey, manufacture to installation.

If you have any queries, please don’t hesitate to contact our friendly team, they are happy to help!


Spire’s quality range of casement windows offer versatility and are the most popular choice available today. When you choose our PVCu casement windows you choose warmth, security and peace of mind. Due to Liniar’s patented double-action bubble gasket and, our high performance double glazing, our windows are draught proof. 


Lower energy bills

Our bow and bay windows come with features that can reduce your heating costs and improve the energy efficiency of your house. Our double-glazed casement windows are reasonably priced and come with A ratings by default.

Safe and secure

All of our windows are manufactured with you in mind. That is why we make all of our windows with the latest security technology.
Sit back and relax knowing that you have invested in your home and your safety.

A warmer home

Everyone likes coming home to a warm house in the winter months. Guarantee cosiness with our energy-efficient double glazed bow and bay windows. Our low emissivity glass minimizes heat loss and condensation by reflecting warmth back into your home with the aid of argon gas and a thermal edge spacer bar.

Bespoke designs

Our bow and bay windows can be customised to fit your home’s style. From colours, configurations, sizes to styles, we have something for you. You can also add features such as leaded glass, decorative sash horns, Georgian or asragal bars!

Money Saving Innovation

Here at Spire Windows we are very proud of the products we manufacture and install. Due to our lead-free, multi chambered profiles and innovative gasket seal thermal dam, our bay and bow frames easily reaches a WER of A+ and a u-value of 1.2 with affordable double glazing.

A world of colour

Not just available in standard white, our bow and bay windows can be customised to suit the feel of your home – as well as its colour scheme!

A world of colour

Trust Spire to manage your home improvement from start to finish


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What is the difference between bow and bay windows?

How many sections each type of window has is the most significant difference between bay windows and bow windows. Another distinction is that bay windows feature a picture window in the middle and two other windows on either side. Each segment of a bow window has the same type of window, and the entire construction is rounded.

What should you do next?

Get a free no obligation quote today with our online quoting tool or get in contact with our friendly team who are happy to help you with any queries you might have. Our team can also provide further information about our popular bow and bay windows! 

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