The Ultimate Bay Window Cost Guide for 2023

Written by  Harry Taylor
Last updated: October 18, 2023

Like many home improvement projects, the costs associated with bay window replacement and installation largely depend on the size of the window unit and the materials that are going to be used in the project. Bay windows are certainly on the more expensive side of the window spectrum, owing to their size and the labour it takes to install them. 

Given the shape of a bay window, the cost of an installation also depends on the number of sections you choose to have. Traditionally, bay windows have three openings, however, some bay windows nowadays have up to 5 sections. The more sections the bay window has, the more expensive it will be to install. 

Number of sections needing replacementPrice range
£1000 – £1400
4£1500 – £1800
4£1900 – £2400
Size of the window
4 ft x 3 ft£550 – £1500
6 ft x 3 ft£750 – £2900
8 ft x 3 ft£800 – £3350
10 ft x 3 ft£1250 – £5850
Frame Materials
Aluminum£300 – £1500
Fiberglass£400 – £2350
Vinyl£450 – £2350
Wood£700 – £3200

Should You Restore or Replace Your Bay Window?

In many cases, it is a lot cheaper to restore your bay windows than it is to replace them completely. When built properly, bay windows can last a long time, and will rarely require maintenance sometimes even up to 40 years. If you have frames made from wood, then you can expect a minimum of 30 years out of your bay window before having to worry about repairing them at all. 

You may need to replace the bay window if there are irreparable flaws or damage. Wooden frames often have the tenancy to go through wood rot or pest infestation if left unmaintained. These are some examples of damage or problems that may require you to get your bay window replaced. 

Bay Window Profile

There are several different types of bay windows and each has a slightly different look which can impact the overall appearance of your project. It’s important to know the type of design you want to go for as this can also have an impact on the price of a bay window. 

Box Windows

Box windows are the most common type of bay window, so called because they create the look of a rectangular box that protrudes from the outside of the house. These windows are great for letting loads of light in and creating additional seating space within a living room or bedroom. The price range for box bay windows will set you back anywhere between £1,000 and £2,500. 

Bow Windows 

Bow bay windows have a curved shape given to them by the angular arrangement of the window panes. The design of these bay windows is the more traditional look used in stately homes and is great for maintaining the original features of older properties. Coming in at a slightly higher ballpark price than box bay windows, bow windows can cost between £1,500 to £3,000.

Circle Bay Windows 

Compared to bow bay windows, circle bay windows have a smoother curve design, giving the impression of a semi-circle extending from the main window frame. To create a smooth curve, circle bay windows need to have a lot more window panes in place than other designs. For this reason, circle bay windows can be in the upper price ranges, with the average price for this design coming in at £1,500 to £3,500. 

Oriel Bay Window

An oriel window is a design that protrudes a lot further out than other bay window designs, meaning they provide the best views of the gardens or landscapes visible from the household. Although not as expensive as circle bay windows, they do tend to take some time to be installed because of the size the window is likely to be. The price range for oriel windows is between £1,500 to £2,500.

Bay Window Size and Weight Costs

The size and the weight of the bay window installation have a big impact on the overall cost of the project. Typically, homeowners prefer larger sizes when it comes to bay windows, as this means more natural light is allowed to infiltrate the room. The bigger the bay window the more expensive the project will be as there will be more materials required during construction, and the installation will become more challenging and take more time when the windows are heavier. 

The Cost of Glass in Bay Windows

The type of glass used in the bay window will also influence the cost greatly. Single glazing is usually the cheapest option for the initial installation project, however, going to multiple glazing options will save homeowners money in the long run. Double and triple glazing are better at insulating the house than single-glazed windows, therefore you can save money on heating and energy bills with higher levels of glazing. 

There are also more benefits associated with double or triple-glazing glass such as soundproofing. This is particularly useful if the property is close to a busy road or a school. You can also achieve soundproofing with acoustic glass, which protects occupants from outdoor noise but also insulates noises from the inside of the home. Although the upfront costs associated with multiple glazing layers will be more, there are significantly more benefits and long-term money-saving potential. 

In some classic homes, decorative glass is very popular in bay windows as it keeps in line with the overall aesthetic of the home. Although decorative glass disables you from viewing the outdoors, it’s popular in rooms where some privacy is required. 

Another popular glass type is self-cleaning glass. This type of glass is also on the more pricey side given that it’s coated to prevent dirt from settling on the panes. Although self-cleaning glass does not remove the need to clean completely, it will save you from having to clean the windows as regularly. 

The Types of Materials Used in Bay Window Installation

Bay window prices are also dependent on the types of materials used to make them. Window frames are usually made out of wood, uPVC, or Aluminium. uPVC is the lowest-cost material and also the most durable as it does not require a lot of maintenance when it’s installed. This makes it the ideal material for environments with extreme weather conditions.

Wooden frames are ideal for maintaining the aesthetic of a traditionally-styled home and are popular among people who want to customise their window frame’s colour. Also low maintenance in the right conditions, wooden frames are more expensive than uPVC but sit in the middle when it comes to price ranges. 

Wooden frames are more prone to damage in bad weather and may require you to replace the windows or have them restored more regularly. On the other hand, aluminium is one of the most durable materials for bay window frames. It’s also a relatively new trend on the market and is popular among those who want to give their homes a more modern look. 

Colour Customising

When you choose to customise the colour of the bay window frame, you will have to take the cost of the paint into consideration. Having customised colour will also require slightly more maintenance than raw material, as you will have to make sure the colour stays in line with the aesthetic you’re going for. You will therefore have to budget for the initial paint job but also regular touch-ups.

When choosing which paint to buy, make sure you choose a product that is suitable for outdoors and provides a bit of protection to the wooden frame. Before choosing your frame material, remember that wood is much easier to customise than aluminium or uPVC. 

Important Factors to Consider When Getting a Bay Window Installed

Before you decide to move forward with a bay window installation project, it’s important to know the factors which influence the cost of the undertaking. As a general rule, the heavier and the bigger the bay window is, the more expensive the product and the installation costs will be. 

Homeowners should also take into consideration the age of the building in which they’re planning on installing bay windows in. If the project is an expansion or restoration, a thorough survey should be conducted to ensure the site can handle the project. 

Additionally, bay window installation or restoration projects depend heavily on the level of customisation already in place or that needs to be installed. Custom-made bay windows will be more expensive with design factors like glass types, frame materials and size metrics being at the key determining factors of bay window costing. 

What else influences the prices of Bay windows?

Other factors mainly surround the installation site and external factors other than the bay window itself. When installing a bay window, there can be a lot of waste generated from the project. For this reason, you may be required to hire a skip for the duration of the installation. Skip hire on a weekly basis can cost between £90.00 and £340.00 dispensing on the size and the length of the hire period.

The location of the installation project is another vital factor to consider before going ahead with a bay window installation project. Usually, the more remote the installation or restoration site is, the more expensive the project becomes. This is because fuel and potential accommodation costs for the installers will become a cost factor in the overall project.


Should I replace old bay windows?

Replacing an old bay window may be the only option, depending on the level of damage the original window has. If there is a problem such as wood rot in a wooden frame or severe glass damage, the window may need replacing. However, if there is a small crack in the glass or minor damage elsewhere on the window, restoration or repair will be a lot cheaper. 

Do bay windows add value?

Bay windows are highly desirable features in households. They expand the view from the room onto the garden or surrounding landscape and provide additional seating within the home. They, therefore, increase the property’s market value. 

Are bay windows more expensive?

Bay windows are more expensive than other types of windows owing to their size and the time it takes to install. They require multiple window panes and often some intrinsic design work prior to installation, also adding to the cost of the project. 

Are bay windows more expensive than casement?

Given the average size of bay windows and the external architectural work associated with installing them, bay windows are more expensive than casement windows. The maximum proce you’ll pay for a standard casement window installation is around the £1000 mark, whereas bay windows can cost significantly more, coming in at around £5500 for customised projects. 

Are bay windows easy to replace?

If you can avoid replacing an entire bay window it would be more economically beneficial. Installing a brand new bay window is challenging especially if the new installation has different size and weight metrics than the initial installation. 

Why are bay windows so expensive?

They are a lot bigger and require more labour to install than other window types, which is why there are often higher costs associated with them. 

Are wooden Bay windows worth it?

Wooden bay windows are great for keeping in line with the traditional aesthetic of older homes. They are, however, significantly more prone to damage and longer term problems than other materials. If you have the means to maintain wooden framed bay windows, they can become a stunning long term feature. 

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