Bow windows guide

Bow windows are a classic and characterful architectural addition. Their curved window panes differentiate from classic bay windows, but this can mean extra considerations when it comes time to replace this type of window.

Material, detailing, number of panes and supplier should all be considered when investing in a new bay window. Plus, thanks to their complex design, a good fitter should be thoroughly vetted as to ensure a good quality finish.

A type of bay window, a bow window projects outwardly from the main walls of a property and creates a curved alcove within the room from which it extends. Bow windows offer a distinct architectural feature to a property, adding character to the interior and exterior of a building and allowing for panoramic views from inside the property.

Typically, bow windows comprise four to six windows positioned at soft angles to create a curved shape, which differentiates it from a canted bay window, which has sides angled at 45 degrees for a more box-like shape. However, the configuration of bow windows can vary with different architectural design options, such as additional window panes that enable a smoother curve. Bow windows can enhance the natural light entering a room and create more space inside the home. This extra space can serve various purposes, including storage or window seating.

While both bay and bow windows protrude outwardly from the main wall of a property, provide increased space and allow light to enter a room, they can vary in the following ways:

• Sizes: A bay window, which usually comprises three glass panels, can offer wider window sizes, while the curved design and use of multiple smaller panes of glass in a bow window might limit the maximum window width.
• Number of window panels: Bow windows typically use four to six window sashes, but this number can be even higher. However, a bay window design is normally restricted to three to four window sashes.
• Window shape: The shape of bay and bow windows differ, with bay windows creating a more angular or rectangular projection with a geometric appearance and bow windows creating a more rounded appearance with a continuous curved-shaped projection.
• Amount of interior space gained: The amount of usable interior space differs between bay and bow windows. Bay windows create a more usable interior space due to their distinct angles. In contrast, bow windows typically provide a shallower curved interior space, which can create a cosy feel for breakfast nooks or window seats.

There are many different styles of bow windows, and the most popular styles are listed below:

• Traditional
• Victorian
• Contemporary
• Arched

Each of the above bow window styles has attractive designs for different architectural styles. 

A traditional bow window tends to have between four and six equally sized window sashes arranged in an even curve to create an arc-shaped design, allowing plenty of natural light to enter a room.

Typically seen in properties from the Victorian era, a Victorian bow window tends to have larger glass sashes. It typically features decorative elements such as intricate detailing, woodwork or mouldings, creating a more extraordinary appearance.

A contemporary bow window can achieve a more streamlined and modern appearance. It has a simpler style with narrower frames, making it perfect for more-modern architecture.

An arched bow window features a curved top to the sashes, and this elegant addition makes it more suited for traditional properties, typically from the Victorian and Edwardian eras.

The variety of bow window styles can cater to different aesthetic requirements, making them suitable for both modern and traditional properties.

Desired durability, budget, maintenance requirements and aesthetics should all be considered when deciding on the most appropriate bow window frame material. Below, we include some essential information about the most widely used bow window frame options and key points for each.

The most widely used window materials for a bow window include:

• Unplasticised polyvinyl chloride (uPVC)
• Wood
• Aluminium
• Composite

We’ve included a summary of features and benefits for each of these commonly used bow window frame materials below:

uPVC window frames, made from a durable plastic, tend to be the most cost-effective choice for bow windows. They offer a wide range of colour, opening and hardware options and are renowned for their durability, longevity and low maintenance requirements.

In keeping with the traditional appearance of bow windows, wooden window frames can offer a charming aesthetic, enhancing the character and appearance of both traditional and modern property styles. Wooden frames offer great versatility in design and style, allowing for options to complement any home. Some homes, such as listed buildings and those in conservation areas, might be required to use timber frames for replacement windows. However, it is generally best to restore original frames, if possible, in order to retain the heritage of older properties. 

A popular choice for homeowners looking for durability and architectural style from their bow windows, aluminium window frames allow for slim window profiles and the option to powder coat in virtually any colour. Aluminium windows, while carrying a higher upfront cost, are renowned for their durability and resistance to rust and rot, making them a low-maintenance and longer-lasting option.

Manufactured from wood, vinyl and fibreglass, composite window frames appear like wooden frames but are often less expensive and more durable.

Budget, desired aesthetics and design requirements are key factors when choosing the most appropriate material for bow windows. Each material has pros and cons, and it’s advisable to pick a bow window frame material based on individual requirements.

Several glass options are available for bow windows, with the most popular options listed below:

• Double-glazed glass
• Triple-glazed glass
• Decorative glass
• Tinted glass
• Low-emissivity (low-E) glass

Here’s a summary of features and benefits for each of these commonly used bow window glazing options:

Double-glazed windows, consisting of two panes separated by an air-sealed space, is a popular and cost-effective choice for bow windows. Double glazing reduces exterior noise and helps maintain a stable indoor temperature by reducing heat transfer from a property, making it more energy efficient than single-glazed glass.

Manufactured similarly to double-glazing, triple glazing adds an extra pane of glass and an additional air-sealed space between the second and third panes. It provides greater energy efficiency than double glazing and further reduces the exterior noise entering the home.

Decorative glass is a popular choice for bow windows, especially those requiring enhanced or intricate designs. It allows for popular design styles, such as stained, leaded or patterned glass, to be incorporated into the bow window. 

Tinted glass is a popular choice when the amount of light passing through a bow window needs to be reduced. It helps reduce the strength of ultraviolet (UV) rays entering a room while offering greater privacy.

Low-E glass is very energy efficient, reducing the heat escaping from a window during colder months. This is achieved by adding a thin film layer on the glass that reflects heat back inside the property instead of allowing it to escape through the glass.

The choice of bow window glass will depend on the desired features related to privacy, design, energy efficiency, noise reduction and UV ray reduction. All of these considerations need to be decided upon by the homeowner.

When examining the cost of a bow window, it’s good to consider how the individual specifications will impact the overall window prices. This can include the window size, installation complexity, number of window panes, window frame material, glazing options and any design or hardware upgrades. The cost of a bow window will also vary depending on the window supplier and manufacturer, the property type or the regional location of the property.

For a four-pane bow, double glazed window prices can vary significantly based on the materials used. For example, the average cost of a uPVC four-pane bow window is between £1,500 and £1,800, while the average cost of a composite-framed four-pane bow window is between £1,400 and £3,600. The same variations apply when considering the number of window panes required. The average cost of a bow window with four window panes is between £1,450 and £1,800, while the average six-pane option would be more expensive, costing between £1,900 and £2,400.

The type of property in which bow windows are required will impact the cost, as there will be a variation in the number of bow windows required for different styles and eras. While a detached property may require two to four bow windows (some reaching to the first floor), a semi-detached or terraced property will normally require two bow windows, and a flat typically has one bow window.

Different suppliers will charge varying amounts for supplying and installing bow windows that meet individual requirements. It’s advisable to obtain quotes from several local window companies to find the best value, ensuring that the selected companies are reputable and offer the expected assurances and warranties. There may be a possibility to obtain double glazed windows grants to help reduce the cost of new windows.

There are pros and cons to consider for bow windows, and understanding them is important when choosing this window style.

Some advantages of bow windows include the following:

• More space and natural light in a room
• Improved window views and increased ventilation
• Enhanced character and aesthetic appeal

Due to the unique design of bow windows, which protrude from a room, additional internal space is gained. This larger window area not only increases the amount of natural light, making for a bigger and brighter room, but it also creates panoramic views of the outdoor space. Furthermore, with more openings, a bow window improves ventilation in a room compared to a standard sash window, for example.

Bow windows are typically seen in character-style properties and add aesthetic appeal, with different bow window styles offering modern and traditional appearances.

Some disadvantages of bow windows include:

• The expense involved
• Decreased energy efficiency
• Reduced privacy
• Increased maintenance requirements

Bow windows are typically more expensive than standard windows, due to the increased design complexity, the number of windows and the more skilled and time-consuming installation process required.

Due to a bow window extending beyond the main wall of a property and its size compared to a standard window, it has a greater area from which heat can escape and is also more exposed to windy weather conditions. For these reasons, a bow window tends to be less energy efficient than a standard window style, such as a casement window.

While blinds, curtains and obscured glass can help address privacy concerns related to bow windows, they offer less privacy than flat windows. This is due to the increased window area and the fact the window extends beyond the main wall of the property, which is usually a concern for properties with ground-floor bow windows or those located in urban areas.

Because a bow window extends beyond the main wall of a property, it’s more likely to experience weather-related wear and tear. This often results in more required maintenance on the bow window and its structure.

It’s important to consider your window requirements and weigh the advantages and disadvantages of bow windows when deciding if they’re suitable for your property.

When getting a quote for bow windows, it’s a good idea to look into the reputability of any window fitters you ask for a quote from and understand what warranties and guarantees each supplier offers. Next, consider the cost of supply and installation of a bow window based on the number of windows required, installation complexity and any desired material, glazing and design specifications.

Understanding the manufacturer, fitting guarantees and warranties for each quote you obtain is advised. Guarantees and warranties should offer consumer protection if the window standard or fitting quality falls short of expectations, maximising the lifespan of any new windows.

When getting a quote for bow windows, it’s a good idea first to decide on the number of windows and count how many window panes are in each. It’s also advisable to consider the material you would like your bow windows to be made from and list any preferred glazing, design and hardware options to ensure that the quotes obtained align with your expectations and requirements. The greatest variation in the cost of bow windows tends to be the number of bow windows required. On average, a bow window will cost between £1,100 and £2,300.

While cost is an important factor when choosing a supplier for bow windows, it’s important to remember that specialist installation skills are required for fitting a bow window, and reputable companies will ensure that your new windows are of good quality and installed correctly.

When considering bow windows for your home, we advise you to obtain multiple quotes from reputable local window companies to understand the price variations and get the best deal for new bow windows.