Elegant Double Glazed Sash Windows – Period Charm with Modern Performance
At Cavendish & Cole, we believe you shouldn’t have to choose between the classic beauty of traditional sash windows and the energy efficiency of modern glazing. That’s why we specialise in double glazed sash windows that retain the elegance of original joinery—while delivering real improvements in comfort, insulation, and noise reduction.
Working across Sussex, Kent, and Surrey, we create and install bespoke timber sash windows, fitted with Slimlite double glazing and high-performance seals, tailored to suit both period properties and listed buildings.
The Perfect Balance of Form and Function
Using ultra-thin Slimlite units, our double glazed sash windows maintain the narrow sightlines and slender glazing bars characteristic of Georgian and Victorian sash windows, while offering significant thermal benefits.
Whether you’re upgrading existing single glazing or replacing old sashes entirely, we ensure every detail—from the horn profile to the putty lines—is in keeping with your property’s style and age.
We offer both:
- New double glazed sash windows made to order in our joinery workshop
- Single to double glazed upgrades of your existing sash windows, preserving the original frames wherever possible
Why Choose Slimlite?
Slimlite glass is specifically designed for heritage properties and conservation areas, offering a discreet solution that meets modern expectations without altering the traditional aesthetic.
Benefits include:
- Slim profile suitable for original sash frames
- Enhanced energy efficiency and draught reduction
- Improved acoustic insulation
- Reduced condensation and maintenance
- Available in Low-E, Argon-filled, or warm edge variants
We work closely with homeowners, architects, and conservation officers to ensure every installation meets planning requirements and enhances—not detracts from—your home’s character.
Seamless Upgrades – Without Compromise
If you love your original sash windows but want better insulation, our single to double glazed upgrade service could be the ideal solution. Where possible, we carefully remove the existing single glazing and replace it with Slimlite double glazing, retaining the original timberwork and enhancing the overall energy performance of the window.
- This approach is perfect for:
- Period properties where full window replacement is unnecessary or undesirable
- Listed buildings, subject to local authority consent
- Homeowners looking to reduce heat loss and draughts while preserving historical value
Craftsmanship You Can Trust
Every double glazed sash window we create is made by hand in our Sussex joinery workshop, using premium timbers such as Accoya and durable hardwoods. All our fixtures, fittings, and sash cords are chosen for both performance and authenticity.
From subtle draught-proofing to traditional putty glazing techniques, every element is designed to last—and to look right at home in your property.
Why Homeowners Choose Cavendish & Cole
- Experts in double glazed sash windows for period homes
- Specialists in Slimlite and heritage-approved glazing solutions
- Single to double glazed upgrades to existing sash windows
- Full compliance with listed building and planning permission requirements
- Skilled, in-house installers and joiners
- Trusted across Sussex, Kent, and Surrey
- Warm, reliable service backed by years of experience
Ready to transform your home?
Call us on 01273 282176 or email us here
Get in touch today for a free consultation. Let’s bring your vision to life—beautifully, traditionally, and made to last.
Get In Touch
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Contact Us
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Brighton, East Sussex -
info@cavendishcole.co.uk
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01273 282176
Cavendish & Cole
Additional Services
At Cavendish & Cole Timber Sash Windows & Doors, we specialise in the design, manufacture, and installation of beautiful bespoke sash windows,
Wooden Sash Windows
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Using ultra-thin Slimlite units, our double glazed sash windows maintain the narrow sightlines and slender glazing bars characteristic of Georgian and Victorian sash windows
Double Glazed
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Whether you live in a listed building, conservation area, or a cherished Victorian or Georgian home, our discreet upgrade solutions deliver the warmth and comfort of modern double glazing, without altering the heritage aesthetics that make your home unique.
Single to Double
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Discreet double glazing designed for traditional sash windows When it comes to upgrading sash windows in period or listed properties, finding a glazing solution that delivers energy efficiency without compromising aesthetics can be a challenge.
Slimlite Glazing
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All our glazing is selected for quality, energy efficiency, and visual compatibility with period-style joinery. We work closely with homeowners, architects, and conservation officers
Glazing Options
Read MoreLiving in a bustling town, near a main road, or under a flight path doesn’t mean you have to sacrifice peace and quiet—nor the classic style of your sash windows.
Noise Reductive
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Privacy glazing is a common requirement in bathrooms, cloakrooms, and entryways—but standard modern options often look out of place in traditional homes. That’s why we source a range of authentic obscured and patterned glass styles that work in harmony with Georgian, Victorian, and Edwardian architecture.
Patterened/Obscured
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If you're renovating a period home or looking into sash window repairs or replacements, you’ll quickly come across a number of technical terms — some of which can sound confusing at first.