Windows For Listed Buildings – Mortice & Green
All the windows we produce are handcrafted to ensure they are exact reproductions of the windows that they will replace, perfect for conservation areas!
At Mortice & Green, we specialise in the repair, restoration, renovation and replacement of windows for listed buildings throughout London. As a family-run business established in 1994, we have over 30 years of experience working with traditional timber sash windows and wooden casement windows in some of the capital’s most historically significant properties. Our highly skilled restorative joiners understand the unique requirements of listed buildings, ensuring every project respects the original character of the property while delivering long-lasting performance. Whether your windows require sympathetic repairs, full restoration or bespoke hardwood replacements, we provide honest advice, exceptional craftsmanship and outstanding customer care from start to finish.
Expert Restoration and Replacement for Listed Building Windows
Listed buildings require specialist care, and window work must be carried out with great attention to detail to preserve the property’s historic character. At Mortice & Green, we have extensive experience restoring original timber windows that have deteriorated over time due to age, weather exposure or lack of maintenance.
Our skilled team carefully assesses each window before recommending the most appropriate solution. In many cases, original windows can be restored rather than replaced, helping to retain the property’s authenticity while significantly improving functionality. Our restoration services include repairing rotten timber, replacing damaged sash cords, renewing pulley systems, repairing glazing bars, restoring window frames, replacing locks and catches, and carrying out comprehensive sash window refurbishment. We also install discreet draught-proofing systems that dramatically improve insulation while remaining virtually invisible once completed.
Where windows are beyond economical repair, we manufacture bespoke hardwood replacement windows that faithfully replicate the original design. Every replacement is carefully crafted to match the existing proportions, glazing bars, mouldings and architectural details, ensuring the finished result blends seamlessly with the surrounding property. Our bespoke windows are available in both single and slimline double-glazed options where appropriate and are manufactured in our independent workshop using premium-quality hardwoods.
Conservation-Compliant Solutions for Historic Properties
Working on listed buildings often involves additional planning considerations, which is why choosing an experienced specialist is essential. Mortice & Green understands the requirements surrounding listed buildings and conservation areas and provides expert guidance throughout every stage of the project.
Our reproduction timber windows are specifically designed to satisfy conservation requirements by closely matching the original materials, profiles and appearance of historic windows. Where permitted, we can also retrofit slimline double glazing into existing sash windows, significantly improving thermal performance while preserving the building’s original character. This allows homeowners to enjoy improved energy efficiency, reduced heat loss and enhanced comfort without compromising the property’s heritage.
Every project is approached with the philosophy of preserving as much of the original window as possible before recommending replacement. This careful restoration-led approach not only protects the historic integrity of your property but also offers excellent long-term value by extending the lifespan of existing timber windows. Our team is happy to advise on listed building consent requirements where applicable, ensuring every project is completed with care, professionalism and respect for your property’s architectural significance.
Why Choose Mortice & Green for Windows for Listed Buildings?
Mortice & Green has built an outstanding reputation across London by combining traditional craftsmanship with exceptional customer service. Unlike many larger companies, every quotation is carried out by one of the company proprietors, and all work is completed exclusively by our own experienced in-house team. We never subcontract projects, allowing us to maintain complete quality control from the initial survey through to final completion.
Established in 1994, we have over three decades of experience restoring and manufacturing traditional timber windows. Our independent workshop allows us to produce bespoke hardwood sash and casement windows to an exceptionally high standard while remaining competitively priced.
We believe in repairing original windows wherever possible, providing honest recommendations based on what is genuinely required rather than what is most profitable. Every repair is backed by a minimum three-year guarantee, while our bespoke replacement hardwood sash windows are covered by an industry-leading 25-year guarantee, giving homeowners complete peace of mind.
By taking on only enough work to ensure every client receives our full attention, we continue to deliver the high standard of craftsmanship, personal service and customer care that has made Mortice & Green one of London’s most trusted sash window specialists.
Areas We Cover for Windows for Listed Buildings
Mortice & Green provides specialist windows for listed building services throughout North London, South West London, West London, North West London and Central London. We regularly work on listed properties across Kensington, Chelsea, Fulham, Putney, Wimbledon, Hampstead, Islington, Hackney, Notting Hill, Mayfair, Belgravia and many other surrounding areas.
Whether your listed property requires sympathetic repairs, complete restoration or bespoke replacement timber windows, our experienced team can provide a free site survey and expert advice tailored to your property’s specific requirements. If you’re unsure whether we cover your area, simply get in touch and we’ll be happy to help.
If your area is not listed, call us on 020 7118 9191 and we will confirm coverage. We travel across London for the right jobs.
How Much Do Windows for Listed Buildings Cost?
The cost of repairing or replacing windows for listed buildings varies depending on the condition of the existing windows, the level of restoration required and whether bespoke replacement windows are needed.
As a general guide:
- Sash cord replacement: from £120–£250 per window.
- Sash window draught proofing: from £200–£400 per window.
- Complete sash window restoration and refurbishment: from £400–£900 per window.
- Bespoke hardwood replacement windows: Prices vary depending on size, design, glazing specification and conservation requirements.
Every listed building is unique, which is why we provide free, no-obligation quotations based on a detailed inspection of your windows. Our honest approach ensures you only pay for the work that is genuinely needed, with expert advice on the most suitable solution for preserving the character, appearance and performance of your property. Call 020 7118 9191 to arrange a visit.
Historic windows were available in a wide range of styles. But the higher the skill of the craftsman, the better chance of survival these old windows have. This is why listed homes are of value as their window panes are made of rare material.
Historic windows are always better to be repaired rather than replaced whenever possible.
A complete replacement should be a last resort, especially if the repair is not within the skills of a specialist wooden window company.
If you live in a conservation area or your home is listed, as per Article 4 Direction, you have restrictions in making significant changes to your windows, in some cases you may need to first seek planning permission.
Any alterations or repairs to the exterior part of your listed property will require the necessary consents.
Some types of windows such as factory made non bespoke windows will not match the historic elements of your home and are best avoided.
In fact, they may end up spoiling the overall appearance of the house or worst still you could be forced into doing the whole job over causing a huge cost to the home owner.
An alternative would be to replace the windows with the closest matching designs that will complement the property.
It may even be possible to fit integral double glazing, subject to the same detailed design as your old panes.
To seek the right consents for replacing your sash panes, look for a specialist company such as Mortice & Green that are approved and recognized by many conservation trusts and have many contacts within most of London’s local council authorities.
The client should apply for consent regarding building regulations but we will of course deal with the technical side of the application for you with your consent, we will then discuss the matter with a council conservation officer to help you to obtain the building consent.
Any listed building consents should be obtained prior to work starting. In the event that permission is not granted and your contractors still carry out the work, you may become liable to pay a fine.
After all, doing any home improvement project without building regulation is actually a civil or even could be a criminal offense. It is, therefore, advisable to get all the necessary consent and approvals before making any alterations to your historic home.
Most established and credible window companies know the importance of consents so they should work with you accordingly. If your existing windows are original but beyond repair, double glazing would be the best alternative. The biggest benefits of double glazing include noise insulation and draught proofing and of course the vital thermal barrier.
The materials of double glazing reduce heat loss and save you money on your energy bills.
To sum up, you will need to apply for consent if the window you are replacing will be a new design, even if it is only the frames that are going to be replaced. The council officer will still need to determine whether the new frames match the overall appearance of the property. Also, if you are changing the type of glazing you have, i. E. From single glazing to double glazing, you will require consent.
In addition, repainting the existing frames with a different color, or if you are replacing the original glass, you will require consent from your local authorities. This is especially true if your home is fortunate to have original crown or leaded glass. All in all, whatever the extent of your window replacement project is, always discuss the exact requirements with a reputable window replacement company.
If you require any further assistance please feel free to call us on 020 7118 9191 we are always happy to provide free advice and can even provide you with a free full report and window survey if you wish.
The report will then empower you to make an informed decision on what you should do with your windows, we are not sales people so will always provide you with honest straight forward options and leave you to decide what is best with our knowledgeable guidance, knowledge is power as they say!
Frequently Asked Questions
What restrictions apply to sash windows in London conservation areas?
In London conservation areas, any external alterations to windows - including replacement with different materials or styles - typically require planning consent from the local authority. Like-for-like repair of existing windows using the same materials does not usually require consent. Replacement with sympathetically designed hardwood reproductions may be permitted where the design matches the original, but this depends on the specific conservation area and local planning authority policy. Mortice & Green advises on the specific requirements for your property as part of every free survey.
Can I replace sash windows on a listed building in London?
Replacing windows on a listed building requires listed building consent from the local planning authority, regardless of what material or style is proposed. In practice, most listed building officers prefer retention and repair of original windows over replacement. Where replacement is unavoidable - due to severe structural failure - a bespoke hardwood reproduction matching the original in every detail is typically the only option that will receive consent. Mortice & Green has experience working with listed building officers and can advise on the consent process.
Will conservation officers accept double glazed sash windows on a listed building?
Conservation officers vary in their approach, but the most commonly accepted solution for listed buildings requiring improved thermal performance is in-situ double glazing of the existing frames - retaining the original windows and fitting slimline double glazed units within the existing sashes. Replacement with new double glazed windows - even bespoke hardwood reproductions - is more rarely approved for listed buildings. Mortice & Green can advise on the specific approach most likely to gain consent for your property.
What documentation does Mortice & Green provide for conservation area and listed building applications?
We can provide detailed specifications, measured drawings, and material descriptions of the proposed windows suitable for inclusion in a planning or listed building consent application. Where required, we can also provide sample sections of the timber moulding profiles to demonstrate matching to the originals. We advise on the documentation required by the specific local planning authority for your area.
How do you ensure replacement windows match the originals on a period property?
Mortice & Green takes detailed measurements and profiles of the existing windows before manufacturing any replacements. We use traditional hand and machine joinery techniques to reproduce the exact moulding profiles, glazing bar dimensions, and sash proportions of the originals. All replacement windows are manufactured in hardwood - typically oak - to match the density and appearance of the original timber. We have been producing period-accurate reproduction sash windows since 1994.