Dining Room Feature Window

Replacement Timber Casement Windows

Our replacement timber casement windows are handcrafted to suit both period and contemporary homes across London and Southern England. Manufactured from Accoya timber and available with high-performance double glazing, our bespoke casement windows are designed to combine traditional craftsmanship with modern energy efficiency, security and durability.

Whether you are replacing ageing timber windows, renovating a period property or upgrading your home’s thermal performance, our made-to-measure casement windows offer an attractive, long-lasting solution.

What is a Casement Window?

A casement window is a window that is hinged on the side, top or bottom of the frame and opens either outwards or inwards. Unlike a sash window, which opens by sliding vertically or horizontally, a casement window operates on hinges, allowing the entire window to swing open. Casement windows are one of the most popular window styles in the UK due to their versatility, excellent ventilation and suitability for both traditional and modern properties.

If you are unsure whether a sash window or casement window is right for your home, our team can advise on the best solution based on your property’s style, age and planning requirements.

Traditional Cotswolds Casement Windows
Bespoke wooden casement windows

Flush vs Stormproof Casement Windows

When selecting replacement timber casement windows, one of the most important decisions is whether to choose a flush casement or stormproof casement design.

Flush Casement Windows
A flush casement window sits completely flush within the outer frame when closed. This creates a clean, understated appearance that is particularly popular in period properties, cottages and heritage homes. Benefits include a traditional appearance, authentic period detailing, and smooth, elegant lines. Flush casements are also ideal for conservation areas and listed buildings.

Stormproof Casement Windows
A stormproof casement window features an opening that overlaps the outer frame when closed. This design offers enhanced weather protection and has become increasingly popular in modern and twentieth-century homes. Benefits include excellent weather resistance, enhanced protection against draughts and strong thermal performance. Stormproof casements are suitable for both traditional and contemporary properties.

Choosing between flush and stormproof casement windows often comes down to the age and style of the property, as well as personal preference.

Styles for Period Homes

Our replacement timber casement windows can be tailored to complement a wide variety of architectural styles.

Georgian Casement Windows
Designed with elegant proportions and traditional glazing patterns, Georgian-style casement windows help maintain the character of eighteenth and early nineteenth-century properties.

Victorian Casement Windows
Victorian properties often feature more decorative detailing and larger panes of glass. Our bespoke designs can replicate original profiles and period features.

Edwardian Casement Windows
Edwardian homes combine traditional craftsmanship with larger window openings and increased natural light. Our replacement windows can be customised to suit these distinctive characteristics.

For homes located within conservation areas, we can advise on appropriate designs that respect the character of the surrounding architecture.

London timber windows
Buckinghamshire Casement Windows

Glazing and Materials

All our replacement timber casement windows are manufactured using Accoya, our preferred timber due to its exceptional durability, stability and long service life. Accoya offers outstanding dimensional stability, a 50-year anti-rot guarantee, lower maintenance requirements and multiple sustainability credentials.

Our casement windows are available with high-performance double glazing to help reduce heat loss, improve comfort and enhance acoustic performance. A range of glazing options is available, including obscured glass, acoustic glass and specialist glazing solutions where required.

Quality, Security and Standards

We manufacture and install replacement timber casement windows to meet high standards of quality, security and performance.
EN 1279
BS EN 1279 is the British standard that governs the manufacture and performance of insulating glass units. In simple terms, it helps ensure that double-glazed units achieve reliable thermal performance and long-term durability.
PAS 24
PAS 24 is a recognised security standard used to test a window’s resistance to forced entry. Casement windows manufactured to PAS 24 standards have undergone independent security testing and offer enhanced protection for your home.
Approved Document Q
Approved Document Q is part of the Building Regulations and sets minimum security requirements for new-build properties and certain renovation projects. Windows designed to meet Document Q requirements have been tested against recognised security standards.
FENSA
As a FENSA-registered company, we ensure replacement windows comply with current Building Regulations and are installed to recognised industry standards.
FSC-Certified Timber
We are committed to responsible sourcing and use FSC-certified timber wherever possible, helping to support sustainable forest management.
Listed Buildings and Conservation Areas
For listed buildings and properties within conservation areas, replacement windows often need to be carefully designed to preserve the character of the building. Our experienced team can advise on appropriate designs and planning considerations.

Energy Efficiency

Modern replacement timber casement windows can deliver significant improvements in thermal performance compared with older single-glazed windows.

Our double-glazed timber windows are available with energy-efficient glazing options and can achieve low U-values, helping to reduce heat loss and improve comfort throughout the year. Benefits include lower heating costs, improved thermal insulation, reduced draughts, greater comfort, and reduced environmental impact.

For homeowners replacing ageing windows, improved energy efficiency is often one of the most significant benefits.

Traditional Cotswolds Casement Windows

Our process

Every project begins with a detailed survey carried out by our experienced team.

1

SurveY

We assess your existing windows, discuss your requirements and recommend the most suitable solution for your property.

2

Manufacture

Your windows are handcrafted to order in our Berkshire workshop using premium-quality materials and traditional joinery techniques.

3

Installation

Our skilled installers carefully fit your new windows, ensuring a high-quality finish and minimal disruption to your home.

Areas we cover

The Sash Window Workshop has been manufacturing and installing bespoke timber windows and doors for over 30 years. We cover London and Southern England, travelling as far north as Northampton, as far east as Colchester, as far west as Bristol and as far south as Bournemouth. If you are unsure whether we cover your area, please contact our team.

Beautiful Casement Windows

Frequently Asked Questions

What's the difference between a flush and a stormproof casement window?
A flush casement sits level within the outer frame when closed, creating a traditional appearance. A stormproof casement overlaps the frame, providing additional weather protection and a slightly more prominent profile.
How is a casement window different from a sash window?
A casement window is hinged and opens inwards or outwards, while a sash window opens by sliding vertically or horizontally within the frame.
Are timber casement windows secure?
Yes. Our timber casement windows can be manufactured to meet PAS 24 security standards and Approved Document Q requirements, providing enhanced protection against forced entry.
Can casement windows be fitted in a conservation area?
In many cases, yes. However, specifications may need to be carefully tailored to meet local planning requirements and preserve the character of the area.
How energy efficient are timber casement windows?

If you are considering replacement timber casement windows for your home, our specialists can help. Contact us today to arrange a free, no-obligation survey and discover how our bespoke timber casement windows can enhance the appearance, comfort and energy efficiency of your property.

Contact us

4 Kiln Lane, Bracknell, Berkshire, RG12 1NA
01344 868 668
info@sashwindow.com

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