Wooden sash Windows

Timber Species     |     Timber Finishes     |     Glass Options     |     Ironmongery     |     Glazing Bars     |     Security     |     Window Cill Options     |     Cleaning & Maintenance     |     Installation & Fitting     |     FAQs

The timber sash window is a classic window design and features heavily on some of the most distinguished buildings in the UK. Our hardwood sash windows offer that same timeless elegancy with modern performance.

By crafting our windows from the highest quality timber, we can ensure a highly durable finish, perfect for the harsh and wet British climate. Each timber sash window is finished from our range of lacquers and paints to suit the project requirements.

Our hardwood timber frames are highly insulating and, when paired with a double or triple glazed unit these timber frames offer excellent thermal insulation.

Timber sash Windows...

  1. can be designed to match your existing windows
  2. can include double or triple glazing
  3. are perfect for listed buildings or conservation areas
  4. can have a square or arched head as required
balcony doors

Timber Species

Our timber sash windows are available to be designed and manufactured using the following timber options:

Engineered Hardwood

Exotic hardwood species that boast impressive resistance against hard weather, shrinkage, bending and swelling. The surface of the wood is exceptionally elegant and is often chosen for its beauty, it can look outstanding with just a transparent paint.


An exceptional modified timber with Class 1 durability for integral strength and a fine textured surface for optimal coating absorption. The development of this wood has reduced shrinkage by 25% for improved stability and it possesses rot resistant properties for a strong barrier against the elements.


Known for its impressive strength and durability Oak creates long-lasting designs. The much-loved native British tree is renowned among British architecture and can still be seen in many heritage properties that’s survived for hundreds of years.

Read more about our timber selection here

Timber Finishes

Our timber sash windows are made with double glazing as standard. Our double-glazed units are extremely well insulating and include a low e coating and argon gas filling as standard. You will typically achieve a Ug value of 1.1 W/m2K.

For higher levels of thermal performance our timber frames can be designed to take a thicker triple glazed unit.

Additional glass options such as solar control coatings, decorative glass, translucent glass, low iron glass and low maintenance glass are all possible.

Glass Options

Our timber casement windows are manufactures with double glazing as standard. The typical glazing specification is 4mm toughened pane, with a 16mm argon gas filling and a 4mm toughened pane with a low e coating.

These extremely well insulating timber windows can achieve a Ug value of 1.1 W/m²K. For enhance thermal performance, triple glazing can also be specified on these casement windows when required.

There are also additional glass options available such as solar control coatings, decorative glass, translucent glass, low iron glass and low maintenance glass.


The ironmongery is what finishes off the style of a timber window composition and we offer a choice of modern and traditional styles to complete your bespoke timber window. From contemporary handles to heritage shapes, you can achieve a finish that suits your architectural design beautifully.

To see the ironmongery options for your project, arrange an appointment with us at our showroom where you can see the options in person.

Glazing Bars

As with all of our bespoke timber windows, we can integrate a tailored glazing bar design into your window design. We offer three options for your glazing bar design:


Elegantly crafted timber glazing bar with a traditional British Architecture aesthetic


Minimalistic and elegant for a sophisticated look


A completely unique glazing bar design that is manufactured to meet your design requirements

Find out more about our glazing bar designs here


At Belgravia Windows and Doors, we manufacture our timber sash windows with high quality timber using carpentry methods that stand the test of time. The methods that we use ensure that the frames possess impressive integral strength, resulting in high levels of security.

The glazing specification we use within our timber sash windows is manufactured using toughened glass as standard, so combined with our timber frames you’re provided with a timber framed product that offers outstanding beauty and strength.

Due to the bespoke nature of each product, we can provide you with the security ratings for your specific product, simply speak to a member of our team for further information.

Window Cill Options


Using the same timber as your windows, we can create flush cills that are painted to match your casement windows for a cohesive finish.


This is a new advancement in window cill manufacture that creates a sophisticated and high efficient finish to casement window installations.

Find out more about our window cill options here

Cleaning & Maintenance

Each timber sash window from Belgravia Windows and Doors is designed for minimal maintenance over its lifetime. We create hardwood windows that are easy to live with and work with. For cleaning, each of our timber sash windowpanes can be unclipped and tilted inwards for easy access; perfect for upper floor windows or windows with reduced access.

The exact maintenance required for your timber window will depend on the timber species you choose, the finish chosen and the environment it is installed in.

Read our ‘Maintenance of Timber’ page for more information.

Installation & Fitting

All of our hardwood timber windows and doors can be installed by our expert team. They are skilled in the art of installing bespoke timber windows and give each project the expert time and attention it deserves.

Our installation team can take charge of the entire window replacement or installation process, including removal of the existing window, installation of the new window and ‘making good’ on the surrounding finishes when complete.

bespoke wooden windows and doors


Can Belgravia Windows and Doors install the timber sash windows?

Yes. We offer a full design, manufacture and installation package for all of our timber framed glazing products.

How do I place an order?

To place an order, speak to a member of our team who will ensure that all elements of design have been considered and chosen ready for the order to be placed and manufacture to begin.

What is the standard glazing specification?

As standard all our products come double glazed with a Low-E coating. This specification can be enhanced with triple glazing or additional technical glass coatings.

With years of experience in the supply and installation of timber framed windows and doors we can offer a tailored service to each client. Whether you are a homeowner or an architect; our experienced team can help advise on the best solution for your project.