U values
from 0.80 W/m2K
Airtightness
Class 4 airtightness with dual compression seals
Material
FSC certified timber
Security
SBD high security option (PAS 24 and Part Q compliant)
Our GBS78 windows are tripled glazed as standard and available as inward or outward opening. GBS78 are suitable for most projects, from replacement right through to deep retrofits and low energy new builds. All of our windows are third party tested for security, air tightness and exposure and all U values are backed up with PHPP ready data and calculation reports. The timber used for our windows is responsibly sourced through FSC® certification.
GBS78 inward opening tilt and turn windows windows are a popular choice as they can be tilted for ventilation or open internally, offering easy cleaning access to both the interior and exterior surfaces.
Inward opening typical maximum sizes: Tilt & turn: 1300 x 2300 mm, Tilt only: 2000 x 950 mm or 1300 x 2300 mm.
For sizes beyond this, please speak to a member of our team.
Our outward opening timber triple glazed windows offer exceptional energy efficiency with a U value of 0.83 W/m2K.
Outward opening windows are available with as top or side hung with typical maximum sizes of: Fixed light: 2500x2500mm, Side hung: 950x1520mm, Top hung: 1300x1650mm.
All of our windows are fully bespoke with any design available
The space between panes is filled with 44mm argon gas.
Available for added safety, ensuring windows open only to a safe, secure limit for children.
Our windows are available in all traditional shapes and sizes, ensuring uniformity throughout your project.
A range of glazing options are available for safety, solar control, privacy and much more.
Options to meet Part Q compliance for accessible windows in new build
With a U value of 0/87 Wm2K
Third-party tested to the highest levels for weather exposure, ensuring durability and long-lasting performance.
Glazing bars with duplex warm edge spacers are available on request.
We promote MVHR when it comes to ventilation, however, if you are unable to accommodate an MVHR system then we can fit conventional trickle vents to your windows. This does affect the thermal performance and airtightness of the window, so please speak to us about ventilation.
Extensions sills protect and maintain windows by directing water away from the window. We have a variety of aluminium extensions sills ranging in size from 25mm to 380mm. We also have profiles available in Acoya timber. All sills can be colour matched to the window.
We offer a range of optional safety features. These include child restrictors to limit the opening of windows. Egress hinges to maximise opening areas of side hung windows for escape. Safety glazing to protect from falling and impact, and lockable handles where required.
Approved Document Q of the Building Regulations for England became mandatory for all new dwellings on 1 October 2016. This means that windows and doors in new dwellings, where Part Q is applicable, will need to be security tested to PAS 24, or equivalent standard.
Please contact us for advice on the best range for your project. Or see our summary and overview of the ranges.
21 Degrees windows & doors are all made from timber. Our ranges are made from FSC® certified Redwood or Oak. Modern timber finishes are now so durable that, for most applications, we recommend them over aluminium cladding or UPVC.
U-Values measure how well heat is transferred by the entire window/ door – the frame, sash and glass – either into or out of the building. The lower the U-Value number, the better the window or door will keep heat inside a building on a cold day.
Download our technical drawings and UKCA declarations regarding our GBS-78 windows & doors.
With FSC® certified timber and low U values, the aluminium clad windows enhance the style and design of your project externally whilst maintaining the warmth and beauty of timber from the inside.
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
See our GBS-78 windows for our clients within our case studies.
All of our products are thoroughly tested and quality assured.
FSC Certified Wood
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.
