Traditional Sash Windows in London

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Traditional Sash Windows in London

Our traditional sash window services

Traditional timber sash windows will offer elegance and refinement to both the façade and interior of your property. The beautiful aesthetic can reclaim the original period nature of the building and provide an interesting talking point.

The exact origins of the sash window lack evidence and is therefore widely debated. Some historians suggest Holland in the 17th century, and some suggest France can lay claim to their invention. The French theory being rooted in etymology; 'sash' coming from the French chassis, meaning 'frame' in French. Others even argue that the Englishman and polymath, Robert Hooke was responsible.

Whatever their beginnings, traditional sash windows grew in popularity during the Georgian and Victorian periods and was the most common construction method for windows at the turn of the 19th century. This trend was short-lived and with the introduction of hinged windows, around the start of the First World War, and they fell out of favour.

A sash window consists of a number of glass panes in a grid formation and usually opens vertically at the top and the bottom. In essence, it works based on a system of weights and pulleys. A casement, or hinged window, usually consists of one pane and opens outwards. This comparative simplicity made the hinged window cheaper and easier to produce and install, which was crucial during the war-time period in London and why it overtook the sash in popularity.

However, in recent years, with the growing desirability for period homes, the sash window has  gained an iconic status. Not only are traditional wooden sash windows aesthetically pleasing from the inside and out, their installation, or restoration, is now a highly sought after feature by buyers,  which consequently, increases the value of a property.

At houseUP, we have limitless passion for period projects and reinstalling or restoring traditional sash windows is one of our services that brings us the most pleasure. As experts who work with skilled craftsman, we would love the opportunity to return your property to its original distinction and style.

As well as more unique or completely bespoke services, some of our common requests for sash windows are:

  • Box sash windows
  • Bay sash windows
  • Victorian and Georgian sash windows
  • Sash windows with shutters
  • Sash window restoration and repairs
  • Sash window sealing

How much do sash windows cost?

Whether you are planning to install sash windows for the first time, replace existing sashes, repair or refurbish, one of our expert team will pay a site visit in order to make an assessment to better provide you with an accurate quote. All our projects are viewed as bespoke and are therefore, priced on an individual basis.

Some of the factors we will assess are:

  • size of the window; height and width
  • type of window and complexity; box, bay or more uniquely shaped, i.e. arched, or swept head, and the number of panes desired materials; timber, uPVC, aluminium; timber is usually the most expensive and uPVC the least
  • type of finishes; i.e. decorative horns and fasteners
  • glazing; double, single, triple, secondary etc.
  • draught-proofing
  • number of windows requiring replacement throughout the property accessibility

As an average guideline, we can suggest that replacing a simple (in terms of design), average-sized, double-glazed, timber sash window in London will cost approximately £1500.

If your property is already blessed with sash windows, a more affordable option might be either restoration or refurbishment. This could involve stripping back paint, replacing or restoring rotting wood, and replacing sash cords and hardware. If required, installing double-glazing and adding draught-proofing can also be included. Depending on the amount of work necessary, costing begins at approximately £500.

Although the initial outlay involved in window replacement or restoration may seem daunting, it is worth remembering that improved glazing and draught-proofing can improve household energy efficiency and therefore lower energy consumption and associated costs.

Traditional sash windows and modern glazing

Poor insulation in the form of ill-fitting windows, cracked panes of glass, or lack of seals could be responsible for high household energy consumption. Improving the efficiency of your windows through replacing shrunken, or rotten, timber frames; adding draught-proofing; and upgrading your glazing could see a significant reduction in your energy bill.

To ensure your period property has its modern comforts, we provide the following glazing services with our installation if required:

Double-glazed sash windows

Providing the existing sash has a depth of at least 35mm, we can replace the current glass planes with double-glazing. If the sash is not the necessary depth, we might suggest crafting a new sash to fit the original frame. This is not only a way of preserving the history of the property, but more cost-effective than a full replacement, although we can offer this too.

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Triple-glazed sash windows

As well as energy efficiency, triple-glazing offers effective acoustic reduction. However, where a 35mm depth in the original frame is required for double-glazing, 40mm is required for triple.


Secondary glazing sash windows

Where double-glazing is a single window comprising two panes of glass separated by an insulating gas, secondary glazing is additional window installed behind an existing window. As there is no alteration to the building's original design, this makes secondary glazing the ideal, and sometimes only, option for listed buildings or buildings in conservation areas. What's more, secondary glazing offers significant draught reduction and energy efficiency that surpasses double-glazing. It is also an effective acoustic insulator.

It is even possible to layer a combination of glazing, i.e. double-glazing and secondary glazing to achieve dramatic results in noise reduction, draught reduction and energy-efficiency.


Our bespoke sash windows

The design for traditional box sash windows can be as simple or intricate as you can imagine. Typical requests in London tend to be trational Georgian sash windows, which are identified by their “six panes over six panes” and multiple glazing bars; or Victorian sash windows, which are “two panes over two panes”, resulting in a cross of glazing bars.

However, if you are hoping for something truly unique and breathtaking, we are always excited by a challenge and can present to you a range of less familiar window shapes and styles. Your vision may be for a window with more or fewer panes, or a combination of more on top and fewer underneath;  an arched shape, Gothic or Palladian; a bay, a box bay, a circle bay; a design with marginal bars and stained glass panes; the list goes on.

Although arguably the most appealing draw to sash windows are their unparalleled beauty, it's not only about aesthetics. Once you have settled on a design, we can customise other features such as materials, efficiency and security.

At the forefront of our values is sustainability in construction and preserving the environment. It's important to us as a company and a thought leader in our industry to use environmentally-friendly  construction materials and be conscious of energy consumption. With this in mind, and if in alignment with your own values, we will opt for using sustainable timber and ensure the installation of your windows is as energy-efficient as possible.


The next step in sash window installation

Whether you are in need of completely replacing the existing windows in your period property for elegant sashes with thermal reduction and reduced noise pollution, or hope to enhance the charm and appeal of your new build by installing a stunning set of wooden box sash windows, we want to guide you through that journey.

Our property-centred and carefully planned projects use high quality, reliable and durable materials at  competitive prices, ensuring not only a sought-after traditional aesthetic, but peace of mind in that your creation is long-lasting and value-adding. Our confirmed commitment to the best customer service reassures that we are reliable, approachable and provide excellent craftsmanship and care when it comes to sash window installation and restoration.

With no obligation, we would like to hear any questions or concerns you have regarding sash windows, be it pricing, materials options, or length of the project, so that you and your property can experience the most beautiful, environmentally-considerate sash windows in London.

View our work

This family townhouse in Greenwich is still one of our favourite projects after several years.



Coleherne Court is a very challenging place to install new windows, and this renovation is one of our most recent completed projects.

Coleherne Court full high end flat refurbishment living room sofa open space.jpg


Traditional sash windows and a super sleek glass door are two of the features of this roof development in Chiswick.

Chiswick Penthouse Traditional Sash Window.jpg
Gen Pagano author | houseUPGen Pagano

Gen is managing director and chief of digital strategy at houseUP. She has a background in information security and product management in tech startups.

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