How Much Do Sash Windows Cost in London? (2025 Prices)

What might affect the price of my sash windows?

Repair vs Replacement

The cost of sash windows depends on whether it’s a restoration project or a replacement, since the materials, labour, and time involved are different in each scenario. 

Sash window restoration will vary depending on the amount of work needed. If they require extensive repairs or upgrading, from single to double glazing, for example, the cost of restoration is likely to be higher.

The cost of restoration versus replacement depends on the current state of your sash windows, including:

• Whether the wood has shrunk or is rotting.

• If hardware needs to be replaced.

• If painting, glazing and draught proofing are required.

Generally speaking, restoring sash windows is less expensive than replacing them, especially if there’s only minor damage to be repaired. For instance, re-glazing may be more affordable than full window replacements.

Replacing sash windows can be a more expensive choice. However, it may work out more cost effective long-term than repairing your current windows. This is particularly true if your timber sash windows shrink and create a draught — it can be a better long term option to replace than fix. New sash windows will prove to be a worthy investment for your home.

A full restoration job typically takes longer than replacing sash windows too. It involves stripping back decades worth of paint, replacing and restoring old wood, and replacing hardware. If you opt for restoration, your windows will need repainting every five to six years, which is an additional cost to consider.

When replacing sash windows nowadays, many opt for uPVC for their low maintenance benefits. They won’t need repainting every few years, nor are they susceptible to rot & insect infestation and are more weather resistant.

Different materials 

Different materials cost different amounts, so it’s an important factor to consider when buying sash windows. The majority of windows you’ll see in the UK are made of either timber or uPVC. Each one has its pros and cons, but also a different price.

uPVC tends to be the most cost effective material, and timber can be on the higher end. However, not all wood is more expensive than uPVC - it depends highly on the quality of wood. Cheaper wood could mean windows don’t last as long.

At Bespoke Windows, we’re most famous for our uPVC sash windows. It’s affordable, long lasting, and versatile — it’s also highly energy efficient. 

We combine uPVC with a variety of internal painted traditional mouldings, including window boards, architraves, and even staff beads, resulting in a high-performance, low-maintenance window.

It offers an affordable price compared to its wooden counterparts. All whilst rivalling the period look of wood.

Timber is a traditional choice that offers classic aesthetics to a home. It is, however, the more expensive option in most cases, and requires ongoing maintenance.

Economy or Heritage windows

We have two sash window ranges: Economy and Heritage.

The Heritage is most commonly used by our customers as it appears the most similar to traditional wooden sash windows, while providing the modern benefits of uPVC.

Our Economy window is a more affordable alternative, however it lacks the period look most of our customers value.

Size and number of windows

The size and weight of your installation will influence the price of your sash windows. For example, the larger and heavier the window, the bigger and more costly the sash balances and glass are.

As the sash balance needs to be designed to support the weight of the sashes and glass, these naturally need to be bigger, and therefore, the cost can increase.

Larger or custom-sized windows require more materials and craftsmanship, and this can raise the cost of sash windows. This will ultimately depend on the size of windows required for your property - for example, if you’re replacing taller bay windows or a more standard size single sash window.

As you might expect, the more windows you need to replace in your property, the more the job will cost.

Conservation area/listed building

Whether your property is a listed building or in a conservation area will have an impact on  overall costs.

Making any adjustments to these buildings requires our special attention. Often, there may be intricate designs that need to be matched to very specific historical details, and it’s these things that boost the price of sash windows. Regulations also need to be complied with. This can increase the cost due to planning application fees and heritage officer consultations.

In some cases, permits are required, in which replacing or restoring sash windows must have prior consent (this can come with a fee).

Timber is often the material used for sash windows in a listed building. For some listed properties or buildings in conservation areas, the windows may need to be replaced like-for-like with wooden frames to retain the window’s original state.

Installing new sash windows may cost more, especially if a bespoke design is necessary or heritage-approved materials are used.

Type of glazing

Alongside the size, style and materials used, the choice of glazing can also affect the price of sash windows. Certain glass can be heavier or more costly to produce.

• Standard single glazing may cost less, but is typically not chosen nowadays due to its lack of energy efficiency.

• Double glazing is the most common option as standard, which offers energy savings long-term.

• Triple glazing is more expensive than double-glazed sash windows, but can offer additional insulation.

Most UK homes have double glazing as standard. Double glazing sash windows cost £1,200 - £4,000 per window, but this is dependent on the cost factors we’ve mentioned in this guide. 

Furniture

This refers to the fixtures used to open or close sash windows. Your choice of furniture will impact the overall cost, particularly if you opt for more expensive materials, which can add up if you’re replacing multiple windows.

Condition of surrounding frames

If there is extra work to be carried out to install sash windows (e.g. if the windows are in poor condition or in need of repair), the cost might be higher. 

If you choose to get sash windows from Bespoke Windows, a full survey will be carried out to identify the condition of the existing window frame and pinpoint how much work is necessary.

Window access

Aside from the actual sash window, it can cost to access the area of the property where the windows are located. If they aren’t in the easiest location, are high up, or your building has structural damage, we may need additional equipment, such as scaffolding, to correctly and safely install your new windows. As a result, the total cost may increase.

Your unique set of circumstances can make the windows cost more or less than the online quote you may have received.

We can confirm quotes through our free home consultations, with a consultation typically taking less than an hour. You’ll then receive written details about windows and a quote for you to consider.

What are the benefits of sash windows for London properties?

There are many benefits to installing sash windows in a London property, including:

• Offering a traditional look and charm, complementing period properties and contemporary houses.

• Versatility: Sash windows can be installed in Victorian terraces, Georgian townhouses, and even modern builds.

• Boosted property value.

• Low maintenance (uPVC sash windows don’t require repainting).

• Sound insulation (particularly important for London properties).

A significant benefit is the energy efficiency of modern sash windows. London period homes weren’t built with the current noise or traffic pollution in mind.

But through our modern insulation and draught proofing methods, these issues can now be addressed.

Sash windows are now more energy efficient, especially if there are double-glazed sash windows. And this is all while retaining the original visual charm of the windows.

Tips when deciding on a sash window quote

When choosing a company to quote for your sash window replacement, the first consideration should be the company’s customer reviews.

Make sure to read the reviews before selecting a business for your sash windows.

These will give you great insight into previous customer experience and may allow you to ask more specific questions to ensure you’re getting the best service.

Another thing is checking your guarantee. While it’s a legal requirement to guarantee windows for ten years, there are companies that hide caveat clauses in their small print, such as the moving parts only being guaranteed for two years.

Ensure you know exactly what you’re getting when you agree to a company’s services.

It’s also important to choose a company with clear experience and expertise, that way you can ensure your sash windows are created and installed to the highest standard.

We’ve been fitting sash windows for nearly 4 decades now, having built a significant reputation across South London.