Call us: 01634 567500
large door sizes
Slimmer than uPVC
low level threshold
Low Threshold Option
safe and strong
Strong and Secure


For smaller door apertures, our Alitherm double doors flood your room with daylight thanks to the thin aluminium profiles maximising the glass sizes. Slim, secure, reliable and attractive double doors for your dining room or bedroom. Or why not talk to us about enlarging an existing window opening and adding a set of doors instead? Better than a window and more functional too. 

One of the best selling UK brands of aluminium French doors, available with or without side panels. Stylish, practical and reliable back doors for your home also suitable inside the home without a threshold for a modern room divider option. 

Choose from modern square frames or a more traditional appearance.  We also offer matching single doors and windows. Even better is the extensive range of low maintenance powder coated finishes and even a durable woodgrain coating.

Technology & Design

The Alitherm double doors with slimline aluminium frames are insulated with deep thermal breaks. The entire door set is, therefore, energy-efficient with low U-value safety glass as standard. You benefit from reduced energy bills and doors meeting current Building Regulations in new extensions. 

Colour choices go beyond regular powder-coated finishes.  The Sensations and Alchemy colour range offers distinctive and beautiful tactile finishes, rougher to the touch and in different colour palettes. 

Light and strong aluminium combine with a strong corner construction creating a strong product compared to pvcu.  Thinner than other aluminium doors to maximise the light into your home and provide excellent access out to your patio or garden.  These doors also come with a choice of either a handle on the one door or both doors. 

Open alitherm double doors

Product Details

Choose from doors opening in or out, with the master door on the left or the right and with a choice of midribs and horizontal glazing bars.  You can also combine these doors with side or top framing and windows, therefore creating beautiful entrance screens, room dividers or a new front porch. 

  • Comes with a contemporary or traditional look to match with your home. 
  • Available with 28mm or 32mm triple glazed units for security, privacy, acoustics or shade.
  • Reliable and secure multi-point locks with high security cylinders. 
  • Internal glazing beads provide additional security preventing removal of the glass from outside. 
  • Customise your doors with vertical or horizontal bars or adding coloured solid panels. 
  • Sophisticated seals and gaskets provide excellent weather performance.

Alitherm double doors in a new apartment


Personalise your new aluminium door with the choice of a contemporary look using a square frame, flat door sash and square detail on the inside.  The traditional option comes with a profiled frame, flat door sash and bevelled appearance inside, replicating the ovolo style of a traditional door. 

Then choose your Alitherm double doors design. All doors come with opening in or out options, hinged on the left or the right.  You can have a door with a midrail, glazed top and bottom or with a solid aluminium panel. Or add vertical bars to the top pane for a more traditional look. Or why not set the midrail  low for a contemporary door with more glass to add light?  You also get to choose between a standard weathered step-over threshold or a low threshold, perfect for pushchairs or wheelchair users. As well as functionality, the low threshold creates a flush look and has a minimal step-over.

Choose from straight or swan-style handles in seven different colours.  We offer white, black, grey, graphite, chrome, satin silver and gold. The come with matching or contrasting colour hinges too. 

Finally you get over 200 different colours to choose from including special textured surfaces and even woodgrain aluminium. Every colour comes with the same low-maintenance properties and needing an occasional clean. 

modern conservatory with Alitherm double doors at the front

Security & Performance

Every one of our Alitherm double doors comes made with your security and safety in mind. As standard we provide toughened glass units to the latest British Standards. Our doors also come with:

  • U Value as low as 1.6Wm2K when triple glazed . 
  • Maximum door sizes up to 2.4m high. 
  • Extruded to Kitemark and other relevant British standards. 
  • Weather tested to the latest performance standards. 
  • Meets PAS24 security standards when specified accordingly. 

Origin OS-44 sliding door in a family home

Product Features


The hardware in your Alitherm residential doors is designed for maximum strength, longevity and security. The doors have a mechanical hand-assembled construction using robust cleats and brackets in the door and frame corners.

All doors have adjustable hinges and lock keeps, making installation easier while providing a fully adjusted functioning door. The multi-point locking system uses a dual lock mechanism with handles on both sides of the door. Aluminium profiles with secure door hinges, deliver added strength and security with everyday reliability. Your new doors come security beaded on the inside.

If you choose a low threshold, this meets Document M building legislation for accessibility.


With toughened safety glass as standard, your doors are safe, secure and protected. Or you can upgrade to higher security glazing, and obscure glazing for porch doors.

As standard, we provide energy-saving sealed units with a soft-coat low-emissivity coating, warm edge spacer bars and argon gas fill. 


Your doors come with a durable powder-coated finish, applied by the systems company to strict quality control procedures. Durable, low-maintenance and easy to keep clean while keeping your doors looking like new.

Alchemy colours offer gold, bronze, silver, steel and black metallic and anodised finishes for your new doors. Cotswold colours offer a range of Heritage colours. Sensations is a cutting edge collection of powder-coated colours in a metallic tactile surface finish with incredible durability and a unique finish to your new doors.

colours available with Dutemänn FD85 Bifolding Doors

Energy Efficiency

Building U-Values measure the overall insulation of your home and the same applies to your doors. The lower the value, the better the performance of your new Alitherm doors.

Current Building Regulations call for U-Values of 1.8W/(m2K) when replacing existing doors or 2.0W/(m2K) for new building projects. Our glass comes with a centre pane U-Value designed to work with the insulated frames and exceed the requirements of current Building Regulations. Therefore you rest-assured your new aluminium doors perform all year round and help lower your heating bills.

Dutemänn FD85 Bifolding Doors

Some of the images on our website are indicative images illustrating how products may look. Please contact us for full product details and specifications.

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