The Heritage Glazing Authority

We invented ultra-thin double glazing for listed buildings.

Complete Conservation Service

From planning applications to final installation, we're with you.

Unmatched Certification Standards

One of only two UK companies holding full BS EN 1279 Parts 1-6 certification.

Authentic Slim Sightlines

Preserve architectural integrity with 6mm sightlines – the slimmest available.

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Heritage Expertise

Heritage Without Compromise

Navigating the complexities of planning and conservation is a challenge we relish. Whether you are retrofitting existing frames or require full heritage replacements, we provide the authority and the products to satisfy the most demanding conservation officers. We protect the past while perfecting the thermal future.

The SlimLite™ Distinction:

  • Elite Certification: One of only two UK companies holding BS EN1279 parts 2 and 3 for heritage units.
  • The Architect’s Choice: We are the industry benchmark for reliability and technical specification.
  • End-to-End Authority: From planning and manufacturing to master-led installation and aftercare.

Authenticity in Every Detail

We believe heritage glazing is a discipline of its own. Our ultra-slim units are engineered to vanish into original features, providing modern warmth while remaining invisible to the untrained eye.

  • The slimmest sightlines approved for sensitive conservation

  • High-calibre performance for traditional timber frames

  • Unrivalled aesthetics with zero heat loss

Visit Us

Visit Our Showroom in Keighley, Bradford

If you’d like to see what our heritage glazing actually looks and feels like, our showroom in Keighley, Bradford is the perfect place to start. You’ll find examples of sash windows, doors, and our latest vacuum glazing on display – and we’ll soon have the only dedicated vacuum glazing showcase in the North.

Whether you’re restoring a period home or weighing up options for a listed property, popping in gives you a real sense of what’s possible. Our team is always happy to chat, answer questions, and talk through your plans so you can make confident decisions.

Contact Us
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About us

Our Story and the SlimLite Legacy

SlimLite™ was born from a calling to solve the “impossible” problem of insulating listed buildings. Twelve years ago, we dedicated ourselves to this niche, and two years ago, we revived the SlimLite™ brand – the original name in heritage glazing. We have taken that founding legacy and injected it with modern engineering to create the market leader you see today.

Manufacturing

Built with Care, Backed by Certification

Every SlimLite™ unit is crafted in-house. We don’t outsource quality. We hold the full suite of BS EN1279 accreditations – parts 1 through 6 – a feat most competitors simply cannot match. This is the “gold standard” of manufacturing. From our Krypton-filled units to the revolutionary LandVac, every product is a masterclass in durability and thermal excellence.

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Request Your Technical Quote

Contact our knowledgeable team today to discuss specifications, performance requirements, and obtain competitive pricing for your project.

"Great service along with a quality product, also the best advice on the different types of the slimlite range."

Martin

via Trustpilot

"Great high quality product, does exactly what it is supposed to i.e. significant improvement in thermal insulation and noise reduction. I had an issue with the order which was immediately resolved. Would thoroughly recommend."

Duncan

via Trustpilot

"Experts in their field, a well run family business. Pleasure to deal with. Good communicators and they produce a quality product."

James Sunderland

via Trustpilot