SL 38 Aluminium Windows and Doors

Reynaers SlimLine 38 windows and doors have been designed to replicate the ‘steel look’ used in many traditional UK homes.

The SL 38 offers the highest levels of performance with excellent levels of security, weather resistance and thermal insulation.

With its slender look, SL 38 is the perfect window and door for modern homes as well as for the renovation of steel-frames, where respecting the original design is of utmost importance.


  • Features
  • Downloads
  • Technical information
  • Opening options
  • Variants
  • Energy Efficiency


In combination with its superior insulation capabilities, the system provides the perfect harmony between durable material, clean design and reliability needed for your home. Renovation of steel-framed windows with modern, slim frame aluminium windows can also enhance the security, noise and energy efficiency of your property.

  • Ultra slim frame
  • Industry leading maximum sizes
  • Double- and triple-glazed options
  • Easy clean egress hinge option
  • Strong and durable
  • Secured by Design accreditation
  • U-value as low as 1.4W/m2K

Style Options

The SL 38 system is available in 3 different minimalistic design variants, Classic, Ferro and Cubic, to perfectly match the requirements of your project. The windows and doors can additionally be provided with double and triple glazing without losing the ultra-slim look.



Min. Visible width frame: inward opening

33.5 mm

Min. Visible width vent: inward opening

23 mm

Min. Visible width frame-vent: inward opening

67 mm

Min. Visible width frame: outward opening

29 mm

Min. Visible width frame-vent: outward opening

80 mm

Min. Visible width T-profile

48 mm

Max. height vent

2800 mm

Max. width vent

1200 mm

Max. weight element

170 kg

Overall system depth frame

99 mm

Overall system depth vent

86 mm

Rebate height

13.5 mm

Min. Glass thickness

16 mm

Max. Glass thickness

55 mm

Min. Glass thickness vent

16 mm

Max. Glass thickness vent

55 mm

Glazing method

Dry glazing with EPDM or neutral silicones

Thermal break

Fibreglass Reinforced Polyamide Strips



  • Air tightness max. test pressure

    4 (600 Pa)

  • Water tightness

    9A (600 Pa)

  • Wind load resistance

    C4 (1600 Pa)

  • Acoustic performance

    45 dB


  • Burglar resistance



  • Thermal insulation

    (Uf)1,9 W/m²K

Opening options

Inward opening

Outward opening



  • Classic

  • Cubic

  • Ferro

Energy Efficiency



  • Thermal insulation

    (Uf)1,9 W/m²K

Visit our Energy Efficiency page for more information

Learn more

Visit our virtual showroom or find a Reynaers at Home Partner near you

You can now visit the Reynaers Showroom any time you like, with our brand new 360° showroom tour featuring our most popular products. We also have a network of dealers throughout the UK that can advise on product choice and installation for any of the Reynaers at Home aluminium systems for your home project.



Reynaers Aluminium provides frames in almost every colour you can imagine. Over 450 different colour options and finish types are available: metallic or anodised, matt or gloss RAL colours, wood look aluminium or even a special low-maintenance and scratch-resistant coatex finish. And what if the colour of your interior does not match that of the façade? Then we offer two colour profiles, coating the inside and outside in different, matching colours.

  • All RAL colours
  • Surface is covered with a top layer
  • Aesthetic value and added protection
  • Matt, glossy, coatex, or metal finish
  • Long-term protection of water and UV
  • Low-maintenance and easy to clean
  • Controlled oxide layer
  • High level of protection with a natural look
  • Preservation original aluminium structure
  • Long-term protection of water and UV
  • Low-maintenance and easy to clean