Bay windows are one of the most recognisable features on British homes, and York has them by the street-full. But not all bays are the same, and the words used to describe them (square, splayed, box, bow) can leave you scratching your head. This guide explains what a bay window is and walks through the main shapes so you can tell them apart and pick the right one.
What is a bay window?
A bay window is a window that projects outward from the face of a wall, creating a small alcove inside the room. Instead of sitting flat, it steps out beyond the main wall line, usually with a central pane facing forward and angled or curved sections to each side. The result is more light, a wider view, and a bit of extra floor space that homeowners love for a window seat, a reading nook or somewhere to put plants.
Bays are common on Victorian and Edwardian houses, and you will spot plenty of bay windows on the period terraces and semis around York. They also feature on plenty of newer builds, because the extra light and sense of space never really goes out of fashion.
The main bay window shapes
The shape of a bay is decided by how the sections join together and the angles between them. Here are the styles you are most likely to come across.
Square bay (box bay)
A square or box bay projects straight out from the wall with a flat front and two sides at ninety degrees, forming a rectangular box. It gives the most usable internal space because the corners are square, which makes it easy to build in a seat or shelving. Square bays suit both period and modern homes and feel solid and generous.
Splayed bay (angled bay)
A splayed bay has a flat front pane with the two side sections set at an angle, usually around forty-five degrees, so the bay tapers back to the wall. This is probably the classic bay shape you picture on a Victorian terrace. It throws light into the room from three directions and has a softer, more traditional look than a box bay.
Bow window
A bow window is a curved bay made up of several equal panes (often four or five) set at gentle angles so they form a smooth arc rather than sharp corners. Bow windows have an elegant, rounded appearance and suit period properties beautifully. Because the curve is gradual, they often span a wider section of wall than an angled bay.
Oriel bay
An oriel is a bay on an upper floor that does not run down to the ground. It is supported by brackets or corbels beneath rather than sitting on its own foundation. You see these on older and grander buildings, and they add character without needing groundwork below.
Which bay window style suits my home?
There is no single right answer, and a lot comes down to the age and style of your house. A few pointers:
- Period terraces and semis often look best with the shape they were built with, usually a splayed or box bay. Matching the original keeps the frontage looking right.
- Curved and softer frontages suit a bow window, which flows nicely and floods the room with light.
- Modern homes can carry a clean square bay or a large picture-style bay without looking out of place.
The window style inside the bay matters too. Most bays are made up of casement windows that open on hinges, which give good ventilation and a neat look. In a conservation area or on a listed property, there may be rules about what you can change, so it is always worth checking the current guidance with your local authority before ordering.
Frame materials for bay windows
Bay windows are available in the same materials as any other window, and the right choice depends on your home and budget:
- uPVC is the most popular for its warmth, low upkeep and value. Modern uPVC bay windows come in woodgrain finishes and heritage colours that sit well on older homes.
- Timber offers an authentic period look but needs regular painting and care.
- Aluminium gives slim sightlines and a crisp, modern edge, often chosen where you want maximum glass.
How much do bay windows cost?
Bay windows sit above the price of a standard flat window because there is more glass, more framework and often more involved fitting, sometimes including structural support. As a rough guide, a replacement uPVC bay window in the UK typically falls somewhere in the region of a few thousand pounds, with the exact figure depending on size, material, glazing and how much building work is needed. Prices vary a fair bit, so the only way to know for your home is to get it measured. You can get a quote here and we will give you a clear, no-pressure price.
FAQs
What is the difference between a bay and a bow window?
A bay window is usually made of flat sections joined at angles, giving a faceted look, while a bow window uses several equal panes set in a gentle curve to form a smooth arc. Bows tend to look softer and often span a wider stretch of wall.
Do bay windows add value to a house?
They can. Bay windows add light, character and a feeling of space, which many buyers like, particularly on period homes where they suit the style. As with any improvement, quality of fitting and how well it matches the house make the difference.
Can I replace a bay window with the same style?
Yes, in most cases a like-for-like replacement is straightforward. If your home is listed or in a conservation area there may be restrictions, so check the current rules with your local authority first.
Are bay windows more expensive than flat windows?
Generally yes, because there is more glass and framework and the fitting can be more involved. The gap depends on size, material and whether any structural support is needed.
Rounding up
A bay window projects from the wall to give more light and space, and the main shapes, square, splayed, box and bow, each bring their own character. Choosing the one that suits your home and matches its age is what makes it look right. Fancy seeing the styles and finishes in full? Download our latest brochure, or request a free quote and we will come and measure up.