Skip to content

Traditional Elegance In The Modern Home

What is a sash window?

A sash window is made of two movable panels, or “sashes”, that form a frame to hold panes of glass. Cotton cords with a nylon core run over the pulley wheels to connect the lead weights to the sash. By far the most common these days are double glazed timber sash windows. Popular in many areas of London, traditional wooden sash windows are often a mandated replacement. Before you make any decisions on your sash window replacements, contact your local council and make sure you’re doing everything above board. If you need to supply technical drawings, just let us know and we will be able to provide them.

When should I bite the bullet and buy new sash windows?

Over time, most wooden sash windows have suffered from periods of neglect. If any wood becomes exposed to the elements for example, timber sash windows can become a chore to use and maintain rather than being a great addition to your home. Repairs can help, but it’s also possible to fit brand new sash windows in the best tradition of the originals. When your windows become difficult to use, they should be changed. If you notice that the window is heavy, or shudders in the frame then it might be time to give us a call. Take a look at our sash window replacement page for more information.

Our Design Philosophy

Design details that were common in single glazed period windows are very important to us; that’s why we’ve made sure that the design features carried over into our double glazed timber sash windows. We pay careful attention to the narrow profiles, the elegant glazing bars, ovolo detailing, and the sash horns. Our dedication to the conservation of London’s original aesthetics means that your double glazed wooden sash windows will be like-for-like. In other words, you will enjoy the modern benefits of double glazing, without ruining the appearance of your period property. We make our windows with one double glazed unit to increase heat efficiency and reduce cost at the same time. We can also produce integral glazing (all the different units will be separate) if you have that need.

What's Included In Our Service?

For full box replacements (when we replace the entire box), we offer basic and comprehensive fit. For Sash replacements we can provide a comprehensive fit only.

Comprehensive Sash Replacement

Replacement timber double glazed sashes installed in renovated box frames (includes painting & draught sealing). For a full rundown please check the sash replacement service page.

Comprehensive Full Box Replacement (New Double Glazed Sashes In New Engineered Timber Box Frames)

Replacement timber double glazed sashes & replacement box frames (includes painting & draught sealing). For a full rundown please check the full box replacement page.

Basic Full Box Replacement (New Double Glazed Sashes In New Engineered Timber Box Frames)

The old boxes are removed and replaced but that’s about it. This is a great option if it’s part of larger refurbishment job in your property.

  • New box frames & double glazed sashes
  • All woodwork factory finished with Teknos micro-porous paints
  • Full draught sealing
  • New lead weights
  • New hardware & security fittings
  • Wedge the window in place and fill the gaps with expanding foam
  • Cut back the wedges & foam
  • Touch up installation marks only
  • Insurance backed guarantee & FENSA certificate

Unless specifically agreed, the following services will not be provided on a basic fit:

  • Sand and cement pointing or temporary silicone seal
  • Rubbish removal. Rubbish will be left at an agreed location on site.
  • Additional hand painting.
  • Architraves, Bullnose / Window boards.

Additional Options

All our products are bespoke, so additional options for sash windows include, but are not limited to:

Paint Options:

  • Any RAL colour.
  • Two-tone paint – separately match both your internal and external colour schemes.
  • Any paint colour or brand you choose, or colour matching to those colours. Certain brands are more difficult to paint with and so may increase the price.

Design Options:

  • Your choice of hardware colour.
  • Your choice of glazing bars. Glazing bars are the strips of timber on the surface of the glass.
  • Curved tops or square tops.
  • Your choice of unique timber moulding.

Other Options:

The History Of Sash Windows

As a staple of London’s architecture throughout the Georgian Period (1714-1837), the Victorian Period (1837-1901) and the Edwardian Period (1901-1910), the traditional sash window can still be found on almost every street in the city.

The varying designs available are indicative of the glass manufacturing techniques used during these periods, and the architectural fashions of the day. Sash window designs steadily evolved as the glass manufacturing techniques became less and less restrictive, and as a result, you can rather accurately date your home based upon the style of the original timber sash windows!

Georgian Period: 1714 – 1837
Window manufacture during this period relied on Crown Glass, a manufacturing technique that was only capable of reliably producing small individual panes. As a result, this period is famous for a high number of panes within a window, and popular designs were ‘6 over 6’ or ‘8 over 8’ styles. Most Georgian Period wooden sash windows were incredibly symmetrical – both in terms of division of the individual sash, and the uniformity between top and bottom sash.
Victorian Period: 1837 – 1901
Sheet Glass manufacturing became more efficient in the 1830s, which overcame many of the limitations that had previously been caused by Crown Glass. This newly refined manufacturing process led to the production of far larger individual panes than was previously possible, or practicable, which led to a significant reduction in the number of panes needed within a window. As larger individual panes became more readily available, the popularity of ‘maximum glass’ designs skyrocketed, and this period saw the popularity of ‘1 over 1’ and ‘2 over 2’ designs.
Edwardian Period: 1901 – 1910
Glass manufacturing techniques did not dramatically change between Victorian Period and the Edwardian Period, however, the designs did not remain static, and window manufacturers began to experiment with far more ornate styles. There was often a staggering disproportion between the simplicity of the bottom sash and the complexity of the top sash. Bottom sashes tended to remain as plain ‘1 over 1’ or ‘2 over 2’ styles, whilst the top sashes began to implement beautiful curves and decorative ‘lights’.


Enjoy being warm and comfortable!

call us: 020 3302 2060 or email: [email protected]

Instant quote
window replacement in nw5 camden

What did we do?

We’ve completed the comprehensive fitting of 2 double glazed sash windows for this customer.

What did the customer think?

“Excellent job, very happy with the new windows. Communication very straightforward with the office and the team turned up on time, kept us informed as the job progressed and cleaned up thoroughly at the end of each day.”

window replacement in nw5 camden

What did we do?

We’ve completed the comprehensive fitting of a 8 double glazed sash boxes for this customer.

What did the customer think?

“Good standard of workmanship throughout and I love the new windows”

window replacement in E3 Bow

What did we do?

We’ve been contracted twice by this customer, and in total we have completed a comprehensive fit of 4 double glazed casement windows for this customer.

What did the customer think?

“Excellent work with a tricky installation and a great finish. The fitters were clean, tidy and very professional.”

window replacement in E3 Bow

What did we do?

We’ve been contracted twice by this customer, and in total we’ve completed the fully comprehensive installation 12 sash boxes, 2 French doors and 1 front door

What did the customer think?

Our windows are fantastic, exactly what we wanted. Everybody that we dealt with was excellent -professional, kind and helpful.
Core sash windows did a great service and I would definitely recommend them.