Timber Sash Windows

Experience the elegance and timeless appeal of timber sash windows, expertly crafted to combine classic design with modern functionality. Whether you're restoring a period property or adding character to a contemporary home, our sash windows are a perfect choice.

Timber Sash Windows Construction On Weights
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What Are Timber Sash Windows?

Timber sash windows use the traditional vertical sliding design, featuring two panels that glide effortlessly within the window frame. They are commonly referred to as:
  • Sliding Sash Windows
  • Hung Sash Windows
  • Box Sash Windows
These windows have been a staple in British architecture, with their classic design enduring for centuries. When properly maintained, they can last over 100 years, making them a sustainable and durable investment.

Key Benefits of Timber Sash Windows

Discover why timber sash windows are the perfect blend of classic charm and modern functionality. From their timeless design and durability to excellent airflow and conservation-friendly features, these windows enhance any home with style and practicality.
Natural Light

The large glazed surface area maximizes natural light, brightening any room.

Durable Design

Crafted exclusively from hardwood, ensuring long-lasting strength.

Weather Resistant

Unlike casement windows, sash windows cannot be blown open or shut.

Excellent Ventilation

Both vertical panels open easily, promoting effective air circulation.

Top-Tier Box Sash Windows Built for Quality and Longevity

At International Windows Group LTD, we exclusively offer top-tier box sash windows renowned for their exceptional quality throughout London. Our products are a perfect mix of great materials and modern technologies, complemented by years of invaluable experience that has earned the trust of numerous clients. We assure clients of long-lasting longevity for their windows by spraying four layers of waterproof paint on our products.

Additionally, our windows are compatible with conservation area by using Victorian style design.

Timber Sash Windows Construction On Springs
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Technical Specifications
& Colour Options

Explore the detailed technical specifications and versatile colour options of our timber sash windows. Each component is meticulously crafted to ensure superior quality, durability, and timeless design, tailored to meet the highest standards of performance and aesthetics.

WOOD

Soft wood: pine, Hard wood: meranti, accoya, oak and other 3 layer glued engineering wood

STRUCTURE

Windows are sled up and down.
Drive supported with lead weight or springs placed in window frame.

PAINT

Scumbles emphasizing wood structure, opaque in full RAL palette 4-layer system for painting with highly dilutable ecological paints, single and double colored joinery

GLAZING

Standard: “24 mm thermofloat” glazing Ug= 1,1 W/m2K Optionally: Triple panel, Safe and anti-burglary window panels, Absorptive and reflective panels, Sound absorption panels, Ornament, satin panels.

OPENING

Standard: Up-down slide

FEATURES

Standard: ferrules of renowned ferrules of renowned companies: Mightons Products. Drive supported with lead weight or springs placed in window frame.

HANDLES

Available standard patterns below

SEALS

Q-lon made by Schlegel

SILICONE

Bilateral silicone covering

GEORGIAN BARS

Mullions bilaterally glued in a color of the window

SPACEBAR

Standard – Aluminum Optional – Plastic-warm frame colors: swhite, black, light brown, dark brown

ADDITIVES

Horns, vents, restricktors,
kolorysash

ACCESSORIES & OPTIONS

Explore a wide range of accessories and options designed to enhance the style and functionality of your windows. Choose from various finishes and designs to perfectly match your needs and preferences.

GOLD

ANTIQUE BRASS

CHROME

SATIN CHROME

SATIN NICKEL

WHITE

BRASS

ANTIQUE BRASS

CHROME

SATIN CHROME

SATIN NICKEL

WHITE

BRASS

ANTIQUE BRASS

CHROME

SATIN CHROME

SATIN NICKEL

WHITE

GOLD

ANTIQUE BRASS

CHROME

SATIN CHROME

SATIN NICKEL

WHITE

Stop restricktors

Timber Sash Windows Crafted for London Homes

At International Windows Group, we design and manufacture high-quality timber sash windows that respect traditional British architecture while meeting modern performance standards. Our sash windows are a popular choice across London, particularly for period properties, conservation areas and homeowners seeking timeless aesthetics combined with contemporary comfort.

Each window is produced in our workshop using carefully selected timber and proven joinery techniques. Whether you are upgrading an existing property or working on a full renovation, our portfolio of completed projects demonstrates the level of detail and craftsmanship we bring to every installation.

Traditional Box Sash Windows with Modern Performance

Our box sash windows follow the classic vertical sliding design, operating on  either traditional weights or modern spring balances. This construction ensures smooth operation, excellent ventilation and long-term reliability.

Unlike many mass-produced alternatives, our timber sash windows are finished with a  four-layer waterproof paint system, significantly improving resistance to weather and extending the lifespan of the timber. When properly maintained, wooden sash windows can last for decades, making them a sustainable long-term investment.

Designed for Period Properties and Conservation Areas

Timber sash windows remain the preferred solution for listed buildings and conservation areas across London. Our designs are compatible with Victorian and Georgian styles, including features such as horns, Georgian bars and traditional proportions.

For homeowners seeking improved thermal performance, we offer double glazed timber sash windows and optional acoustic glazing. These solutions improve energy efficiency while maintaining the original appearance required by local planning authorities. More technical details can be found in our technical drawings.

Materials, Glazing and Finishing Options

We manufacture timber sash windows using a range of high-quality materials, including pine, meranti, oak and engineered laminated timber. All glazing units are carefully selected to balance thermal insulation, security and sound reduction.

Our sash windows can be finished in any RAL colour, with options for dual-colour joinery, decorative glass and premium ironmongery. Full specifications and certifications are available in our certificates section.

Complete Service – From Consultation to Installation

We provide a complete service, starting with consultation and technical advice, followed by  manufacturing and professional installation. Our experienced fitting teams ensure precise installation and a clean finish, helping your new sash windows perform as intended.

If you are comparing different window types, you may also wish to explore our timber casement windows or  UPVC sash window options.

Request a Quote for Timber Sash Windows

If you are considering timber sash windows for your home in London, our team will be happy to advise you on the most suitable solution. You can view examples of our work in  the portfolio or contact us directly via our contact page to request a quotation or arrange a consultation.