Replacement Double Glazed Sash Windows

At Mortice & Green, we specialise in manufacturing and installing replacement double glazed sash windows for period properties throughout London. As a family-run business established in 1994, we have over 30 years of experience producing bespoke hardwood sash windows that combine traditional craftsmanship with modern energy efficiency. Every window is manufactured in our independent workshop using premium-quality oak and hardwood, carefully designed to replicate the original appearance of your existing windows while providing all the benefits of modern double glazing. Whether your property requires complete window replacement or bespoke reproduction windows for a listed building or conservation area, our experienced in-house team delivers exceptional workmanship and outstanding customer care from start to finish.

Beautiful Hardwood Sash Windows Designed to Last

Original timber sash windows add character and elegance to any property, but after decades of exposure to the elements, some windows reach a stage where repair is no longer the most practical solution. When this happens, our bespoke replacement double glazed sash windows provide the ideal alternative.

Each window is individually manufactured to match the exact proportions, glazing bars, mouldings and architectural details of your original windows. This ensures your new windows retain the traditional appearance of your property while offering the durability and performance expected from a modern installation.

Unlike mass-produced alternatives, our replacement sash windows are handcrafted using high-quality hardwoods, providing exceptional strength, longevity and resistance to the British climate. Every installation is carried out by our experienced restorative joiners, ensuring a flawless finish and smooth operation for many years to come.

All of our replacement sash windows are backed by an industry-leading 25-year guarantee, giving you complete confidence in the quality of your investment.

Modern Performance with Traditional Character

Our replacement double glazed sash windows are designed to improve the comfort and efficiency of your home without compromising its period appearance.

Modern double glazing significantly reduces heat loss, helping to improve energy efficiency and lower heating costs throughout the year. It also helps minimise external noise, making your home quieter and more comfortable, particularly in busy areas of London.

Where appropriate, we manufacture bespoke reproduction sash windows suitable for conservation areas and listed buildings, carefully matching the original design while meeting conservation requirements wherever possible. Our team has extensive experience working with conservation officers and understands the importance of preserving the architectural character of historic properties.

Whether you require traditional single glazing or slimline double glazing, every project is tailored to suit your property’s individual requirements, ensuring the finished result complements the original building perfectly.

Why Choose Mortice & Green for Replacement Double Glazed Sash Windows?

Since 1994, Mortice & Green has built a reputation as one of London’s leading sash window specialists by combining traditional joinery techniques with exceptional customer service.

Unlike many larger companies, all quotations are carried out by one of the company proprietors, and every installation is completed by our own highly skilled in-house team. We never subcontract our work, allowing us to maintain complete quality control throughout every stage of the project.

Our independent workshop enables us to manufacture bespoke hardwood sash windows specifically for each property, ensuring every detail matches the original design as closely as possible. We believe in providing honest advice and will always recommend repairing existing windows where appropriate before suggesting full replacement.

With over three decades of experience, premium-quality materials, expert craftsmanship and an industry-leading 25-year guarantee on all replacement sash windows, Mortice & Green continues to be the trusted choice for homeowners across London.

Areas We Cover for Replacement Double Glazed Sash Windows

We manufacture and install replacement double glazed sash windows across London for homeowners, landlords and owners of period and heritage properties.

Our team regularly carries out installations in:

• Kensington
• Chelsea
• Fulham
• Putney
• Wimbledon
• Hampstead
• Islington
• Hackney
• Notting Hill
• Mayfair
• Belgravia

We also serve customers throughout:

• North London
• South West London
• West London
• North West London
• Central London

If your property is located elsewhere within Greater London, our team will be happy to discuss your project and confirm availability. We provide free, no-obligation site surveys and expert advice to help you choose the most suitable replacement sash windows for your home.

How Much Do Replacement Double Glazed Sash Windows Cost?

The cost of replacement double glazed sash windows depends on several factors, including the size of the windows, the style of the property, the glazing specification and whether bespoke reproduction details are required.

Every window is individually manufactured to suit your property, so prices vary depending on the complexity of the project. Factors that can influence the cost include:

• Window size and configuration.
• Hardwood or oak construction.
• Slimline or standard double glazing.
• Conservation or listed building requirements.
• Decorative mouldings and bespoke joinery details.
• Number of windows being replaced.

At Mortice & Green, we provide free, no-obligation quotations following a detailed survey of your existing windows. Our experienced team will advise whether replacement is the most suitable option or whether restoration may offer a more cost-effective solution. With honest recommendations, exceptional craftsmanship and windows built to last for decades, you can be confident you’re making a worthwhile investment in your property.