Sash Windows
Cost for your windows & doors
Get started today and complete our form to request your free quote
uPVC Sash Windows - Double Glazed Sash Windows
Mechanically Jointed uPVC Sash Windows from The UK’s No1
Aluminium Sash Windows - Get a Quote Today!
Timber Sash Windows Best Prices From the UK’s No. 1
ECOslide Vertical Sliding Sash Windows | Victorian Sliders
Sash Windows
Supply only | Supply & Fit
At Windows Doors Ltd, , we design, supply and install bespoke sash windows across the UK. You can choose from uPVC, timber or thermally broken aluminium sash windows to match your property’s style and performance goals. Every sliding sash window is made to measure, tested for energy efficiency, and available with PAS 24 security options and conservation-friendly detailing.
Watch The Video Overview Of Our Sash Windows
At Windows Doors Ltd, , we design, supply and install bespoke sash windows across the UK. You can choose from uPVC, timber or thermally broken aluminium sash windows to match your property’s style and performance goals. Every sliding sash window is made to measure, tested for energy efficiency, and available with PAS 24 security options and conservation-friendly detailing.
What Are Sash Windows
At Windows Doors Ltd, , we design, supply and install bespoke sash windows across the UK. You can choose from uPVC, timber or thermally broken aluminium sash windows to match your property’s style and performance goals. Every sliding sash window is made to measure, tested for energy efficiency, and available with PAS 24 security options and conservation-friendly detailing.
Why Choose Sash Windows With Us?
- Authentic detailing with modern performance
- Authentic detailing with modern performance
- Secure hardware options, including child safety restrictors
- Authentic detailing with modern performance
- Authentic detailing with modern performance
Materials of Double Glazed Sash Windows
uPVC
Our Windows Doors Ltd are engineered for thermal insulation and low maintenance.
They feature multi-chambered frames, warm-edge double glazing, and tilt-in sashes for easy cleaning.
With A+ BFRC energy ratings, multi-point locks, and dual-colour or woodgrain finishes, they’re ideal for modern homes that want classic style with zero upkeep.
Timber
Our timber sash windows also interchangeably called “box sash windows” are built from engineered hardwood or softwood for long-lasting strength and heritage accuracy.
Each frame is factory finished with microporous paint coatings that allows the wood to breathe, reducing maintenance and preventing cracking.
Choose from nine standard colours or over 200 RAL options to match your property’s original character.
These windows are often specified for listed buildings and conservation areas where authenticity is essential, yet they still achieve A or B BFRC ratings.
Aluminium
Our Windows Doors Ltd are engineered for thermal insulation and low maintenance.
They feature multi-chambered frames, warm-edge double glazing, and tilt-in sashes for easy cleaning.
With A+ BFRC energy ratings, multi-point locks, and dual-colour or woodgrain finishes, they’re ideal for modern homes that want classic style with zero upkeep.
Performance That You Can Feel
U-Value
Superior thermal insulation
U-Value
Superior thermal insulation
Air Resistance
Minimal air leakage
All our sash windows are independently rated by the British Fenestration Rating Council (BFRC), the UK’s
trusted authority for window energy performance.
Typical ratings include A+ for uPVC, A or B for timber, and B for aluminium models. These ratings are
based on U-values, solar gain, and air leakage resistance.
Every product meets Building Regulations Part L and contributes to a warmer, more efficient home.
Double Glazing as Standard
All sash windows supplied by Colin’s Sash Windows are double glazed as standard. Each unit includes sealed glass panels with warm-edge spacers for improved thermal and acoustic performance. This combination helps achieve modern U-values while maintaining the traditional character of vertical sliders.
We do not retrofit double glazing into existing single glazed timber sashes, as doing so can compromise frame integrity and building regulation compliance. Instead, we provide a specialist Secondary Glazing system for homeowners who wish to retain their original single glazed windows but still improve insulation and noise control.
Our secondary glazing is a discreet internal frame fitted behind the existing window, reducing heat loss and outside noise without altering the building’s exterior, a popular option for listed buildings and conservation areas.