U value
0.87 W/m2K
Triple glazed
All of our windows are triple glazed as standard
Class 4 air permability
Offering the only Class 4 Air Permeability rating on the market
Part Q compliant
Security upgrades are available
Traditional horn detail
Traditional horn detailing to the top sash as standard. Options to have variation on the horn detail, or to add a horn to the bottom sash.
GBS Sliding Sash is an ideal choice for low-energy projects, whether simply replacing your windows or specifying for a new home.
Our sliding sash window is triple glazed as standard and has been tested to class 4 airtightness, making it a standout choice when balancing high performance with traditional aesthetics and functionality.
With a choice of designs and styles, our sliding sash window brings character and elegance to your project, without compromising on performance.
Offers the only Class 4 Air Permeability rating on the market for traditional sliding sash window
Integrated through the head of the frame, it’s invisible both internally and externally. We recommend MVHR for optimal performance.
Standard on the top sash, with customisable options for horn variations or additional horns on the bottom sash
Can be used alongside our other ranges of windows and doors and painted to match, ensuring consistency throughout your project
Traditional ironmongery is included with a range of finishes
Options to meet Part Q compliance for accessible windows in new build
All of our windows are triple glazed as standard with our Sliding Sash window having a U value of 0/87 Wm2K
Including balance covers as standard to give the most traditional appearance possible
Glazing bars with interstitial warm edge spacers can be added in any configuration
From obscure to transparent, we can offer plenty of choice for window and door glazing. Make your project unique with our various glazing options and glass finishes.
Yes, we can supply colour matched timber extension cills as standard on our sliding sash windows
Yes, we have a range of traditional ironmongery in assorted designs and colours. If you have seen a certain style you like, send us a link and we can check its compatible.
Yes, our sliding sash window has been tested to satisfy Approved document Q of the building regulations and PAS24.
We use the RAL classic range as standard and have a selection of wood stains too. our products can be dual colour. If you require a different colour range, please speak to one of the team.
Yes, with our Patented SashSealer technology we deliver the only Class 4 Air Permeability tested traditional sliding sash window on the market.
Yes, you can choose to have the top and bottom sash as sliding or fixed.
Yes, we use timber glazing bars with interstitial warm edge spacers inside the glass units. This maximises thermal performance whilst giving a traditional aesthetic. The bars can be in any configuration.
Argon-filled triple glazing as standard for comfort and great thermal performance
Dual compression seals ensuring long-term class 4 airtightness
Multipoint locking tested to Secure by Design standard
Download our technical drawings and UKCA declarations for our windows & doors.
All of our products are thoroughly tested and quality assured.
Part Q Compliant
Secured by design
Windows are a big investment, so come and visit our showrooms or catch us at exhibitions around the UK to see our products for yourself.
Tell us about your project, and we'll make sure you get a no-obligation quote from us. Take a step towards a more energy-efficient home today.
We offer a friendly and responsive aftersales service for our windows and door ranges, with a dedicated office and on-the-road aftercare team.
