Aluminium windows

Modern designs with high quality performance

Over 30 years of specialist door system manufacturing

Sunflex-trained and supported installers located nationwide

Aluminium Doors & Windows

For more than 20 years, SUNFLEX UK has been providing contemporary, high quality aluminium windows. The extensive range of aluminium windows includes made-to-measure options for almost any type of project, from new build to renovation, or replacements for existing units.

The windows are available as top-hung, side-hung casement, tilt-and-turn, folding, fixed frame, gable end glazing, clerestory windows, over-lights, and frameless glass-on-glass corners.

The SUNFLEX UK aluminium window profile consists of a modern contemporary design with square edge profiles to match our aluminium bi-fold and sliding doors. Available in double or triple glazed systems, the windows achieve impressive thermal performance.

With SUNFLEX UK providing the windows, bi-folds and sliders for projects – all of which are made at the same time in the same manufacturing plant – uniformity for your project is ensured.

Made in Britain PAS 24
  • Aesthetic appeal Slim frames, contemporary square edge profiles, and stylish handle design
  • Infinite configurations Every frame is bespoke made to your exact requirements allowing you to customise the design and openings for every window
  • Industry leading performance Superior water tightness from (900Pa – Class 9a*) and air permeability (600Pa – Class 4*) testing performance.
  • Easy to operate Ergonomic handle design, easy clean hinges and secondary locking for background ventilation.
  • Modern look with high quality performance
  • Custom made to exact sizes and designs
  • SUNFLEX UK trained and supported distributors across the UK

  • SAL300 Slim

    Glazing: Double glazed

    Uses: Casement (including top hung or side hung) and fixed frames

    The highly engineered window system provides a modern, slender framed window with stylish square edge profile. Designed from frames with 53mm depths, the SAL300 Slim can be manufactured to the exact requirements of your home, including side and/or top hung sashes if openings are required.

    The slender frames also make the system perfect for large fixed frame picture windows where the goal is to maximise the amount of glass to make the most of the view out into the garden and beyond.

  • SEF

    Glazing: Double or triple glazed

    Uses: Casement (including top hung or side hung), tilt & turn, fixed frames, frameless glass-to-glass corners and inline joints, gable end glazing and angled frames.

    Available double or triple glazed for the ultimate in thermal efficiency, the SEF window is hugely versatile with a wide range of opening options and capable of achieving larger sash sizes.

    The versatility of the system makes it ideal for multiple window styles on the same property or elevation and it is also ideally suited for integration alongside our sliding or bifold doors to create a complete glazing solution.

Opening styles

Side Hung

Opening out from the side, the handle is usually half way up the window. They feature egress hinges to help escape in an emergency and easy clean hinges to slide the window along when open and clean the outer glass.

Top Hung

Opening out from the bottom with a handle along the bottom, this design can provide wider openings than side hung. Restrictor hinges limit how far the window can open with built in subtle finger latch to allow the window to open further.

Tilt & Turn

Ideal for providing a more modern window appearance, with larger openings than conventional open-out windows. The inward opening tilt-and-turn mechanism is ideal for high-level windows allowing them to be easily cleaned from the inside. Alternatively, the handle can be locked to give a tilt-only operation of the window for ventilation.

Fixed Frames

Whether utilised as individual picture window or integrated alongside opening sashes to create a casement window, our fixed frames provide a versatile addition to any window design. To create a seamless design you can even opt for a dummy sash to ensure a consistent design with the opening elements.

SAL300 Slim SEF
Suitable for Newly prepared openings or replacement windows Newly prepared openings or replacement windows
Profile shape Outer: square edge
Inner: square edge
Outer: square edge
Inner: square edge
Window Energy Rating B A
U-Value Double Glazed From from 1.4 W/m²k† from 1.2 W/m²k†
U-Value Triple Glazed From not available from 1.1 W/m²k†
Side Hung Yes Yes
Top Hung Yes Yes
Fixed Frame Yes Yes
Frameless Corner No Yes
Tilt & Turn No Yes
Angled Fixed Frame No Yes
Dummy sashes Yes Yes
BSI Kitemark YES - BS6375 Weather & BS7950 Security YES - BS6375 Weather & BS7950 Security
Water tightness To 300Pa (Class 7a)* To 900Pa (Class 9a)*
Air permeability To 600Pa (Class 4)* To 600Pa (Class 4)*
Frame depths 53mm 65mm or 99mm

* Water tightness and air permeability test performance is dependent upon a number of factors including window size and opening configuration.

† Thermal performance is dependent on glass specification.

Why choose aluminium windows?

Aluminium is the perfect material for manufacturing windows. It is lightweight and yet considerably stronger that other window materials enabling us to create windows with slimmer frames and for larger openings, with narrower frames allowing for larger panes of glasses, maximising the amount of light you let in.

Unlike previous generations of aluminium windows, modern systems are thermally broken which prevents cold-bridging and ensures the systems are capable of advanced thermal performance, with aluminium also offering maintenance-free and recyclable solution, reducing the impact on the environment.

Aluminium Glazed windows

Colour options

We have chosen a selection of the most popular colours for each system to hold in stock. In addition to our standard colours, you can personalise your windows with a choice of more than 200 RAL finishes, and even opt for different colours on the interior and exterior frames of the doors to perfectly match your home.

Aluminium windows - Standard colours

  • Anthracite Grey (RAL 7016) matt finish Anthracite Grey (RAL 7016) matt finish
  • Charcoal Grey Metallic (DB703) textured finish Charcoal Grey Metallic (DB703) textured finish
  • Jet Black (RAL 9005) matt finish Jet Black (RAL 9005) matt finish

Aluminium windows - Popular bespoke colours

  • Slate Grey (RAL 7015) matt finish Slate Grey (RAL 7015) matt finish
  • Grey Aluminium (RAL 9007) semi-gloss finish Grey Aluminium (RAL 9007) semi-gloss finish
  • Traffic White (RAL 9016) matt finish Traffic White (RAL 9016) matt finish
  • Graphite Black (RAL 9011) matt finish Graphite Black (RAL 9011) matt finish
  • Sage Green (RAL 6021) matt finish Sage Green (RAL 6021) matt finish
  • Pearl Mouse Grey (RAL 7048) matt finish Pearl Mouse Grey (RAL 7048) matt finish

Window Handles

  • Side & Top Hung Handles

    Side & Top Hung Handles

    Stylish, slender handle design

  • Tilt & Turn Handles

    Tilt & Turn Handles

    Handle design dependent on size of window

Window Sight Lines

  • SAL300 Slim

    SAL300 Slim

  • SEF Tilt & Turn

    SEF Tilt & Turn

  • SEF Casement

    SEF Casement

Become an accredited distributor

If you are in the glazing trade join our distributor programme today and you’ll receive discounts on select showroom models, the choice of over 40 products for your inventory, and training and technical support directly from SUNFLEX UK.

Find your local distributor