In true GBS style, this wasn’t just another installation. It was a careful blend of trust, care, and excellence — values that guide every decision we make and every piece of timber we craft.
Understanding the Challenge: Heritage Meets Modern Safety
The homeowner’s property is Grade II listed, meaning the replacement window had to be a faithful reproduction of the original design, right down to the proportions and traditional flush casement style. But this project had an added layer: the new window also needed to meet Building Regulations Document B (fire regulations) for clear opening width, height, and overall escape square meterage.
The existing window didn’t meet the current fire-escape requirements, but the replacement must comply. The challenge? Achieving the correct egress dimensions without compromising the building’s historic aesthetic.
GBS Joinery’s Solution: Craftsmanship that Respects the Past and Protects the Future
Thanks to decades of experience working on listed and conservation properties, GBS Joinery knew exactly how to navigate the balance between heritage accuracy and safety compliance.


To meet the regulations, we designed and installed:
✔ Double-opening flush casements with no central vertical mullion
This delivered the required opening size while preserving the authentic appearance demanded of the listing.
The homeowner, a serving fire officer, understood the requirements intimately. They were delighted that GBS Joinery could not only meet the modern fire-escape criteria but also fully honour the architectural style of the property.
That’s the standard we hold ourselves to: craftsmanship that protects what matters most – your home, your safety, and your property’s heritage.
The Golden Thread in Action: Trust, Care, Excellence
Throughout the project, the GBS team took great care to:
– Advise clearly and honestly on what was required for both listing compliance and fire safety
1. Planning Permission May Be Required
Conservation areas are protected to preserve historic character. This can include restrictions on:
– Windows
– Doors
– Trees, hedges, gates
– Cladding and external alterations
Some areas also have an Article 4 Directive, removing permitted development rights and increasing what requires formal approval.
2. Responsibility Lies with the Homeowner
Solicitors should tell you when you purchase a home in a conservation area, but the responsibility to comply rests entirely with you.
3. Always Replace Like-for-Like in Timber
Original features were designed by architects of the era. Replacing them with uPVC or timber-look alternatives (with storm casements or fake grain) often destroys the property’s character, and may be rejected by the conservation officer.
4. Seek Expert Advice Before You Commit
Installing the wrong type of window can result in enforcement action, and costly replacements. To avoid this:
– Contact your local conservation officer, or


With over 40 years of excellence crafting traditional timber windows and doors, GBS Joinery is trusted by homeowners, architects, and conservation officers alike.
If you’re considering replacement windows for a listed or conservation property, we’d be delighted to guide you through the process with honesty, care, and exceptional craftsmanship.
We are always pleased to freely provide the best possible information and expert advice to ensure your timber windows and doors protect your home’s past, whilst safeguarding its future. We welcome your call so please do contact us for a no obligation consultation.
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