Slimline Double Glazing for Timber & Sash Windows
Upgrade period windows with discreet slim double glazed units — without replacing original frames
- Ideal for heritage properties
- Improved comfort
- Specialist sealed unit replacement
Love Your Period Windows — But Not the Heat Loss?
Older timber and sash windows often suffer from:
- Poor insulation
- Cold draughts
- Condensation
- Single glazing
- High heat loss
Many homeowners are told the only solution is full window replacement.
But replacing original timber frames can:
- Reduce property character
- Affect conservation approval
- Be expensive
- Be unnecessary
- Slimline double glazing offers a smarter solution.
What Is Slimline Double Glazing?
Slimline double glazed units are specially manufactured with reduced cavity thickness.
They are designed to:
- Fit into existing timber rebates
- Maintain traditional sightlines
- Preserve period aesthetics
- Improve thermal performance
This allows you to upgrade from single glazing to double glazing while retaining your original
frames.
Can You Retrofit Double Glazing Into Timber Windows?
In many cases — yes.
If your timber frames are:
If your timber frames are:
- Structurally sound
- Not rotten
- Deep enough to accommodate slim units
We can replace the existing glass with slimline double glazed units.
We assess:
We assess:
- Frame condition
- Rebate depth
- Structural integrity
If suitable, we upgrade the glass only.
We Install Cat Flaps In:
Improved thermal insulation
Reduced condensation
Lower heat loss
Maintain original appearance
Suitable for period homes
This is particularly popular for:
Victorian properties
Edwardian homes
Traditional terraces
Properties in conservation areas
Preserve Character. Improve Comfort.
Before – Standard sealed unit
After – New sealed unit with integrated cat flap
Replacing the glass ensures a clean, secure and professional finish.
Suitable for Heritage Properties
Slimline double glazing is often more acceptable for:
- Conservation areas
- Listed building discussions
- Period property renovations
We recommend checking with your local authority where required.
We provide professional advice based on your property.
How Much Does Slimline Double Glazing Replacement Cost?
Costs depend on:
- Window size
- Glass specification
- Slim unit thickness
- Safety requirements
Slimline units are typically more expensive than standard sealed units due to specialist
manufacturing.
However, upgrading the glass is often far more affordable than replacing the entire window.
For a personalised quote:
However, upgrading the glass is often far more affordable than replacing the entire window.
For a personalised quote:
Slimline Double Glazing Across Leicestershire & The Midlands
RUK Glazing is based in Leicestershire and covers:
- Leicester
- Wigston
- Oadby
- Loughborough
- Hinckley
- Market Harborough
And surrounding Midlands areas.