Zyle Fenster
Reynaers Ultra Slim SL38
A slimline aluminium window system for projects where narrow sightlines, natural light and strong thermal performance are equally important. SL38 offers three external profile styles and supports double or triple glazing.
Slim proportions for contemporary and heritage-led design
With a minimum visible frame-and-vent width of 67 mm, SlimLine 38 creates generous glass areas and restrained framing. Its proportions also make it a considered replacement for older steel windows where improved comfort and weather performance are required without losing the original visual rhythm.
Thermally broken and independently tested
Polyamide thermal breaks, drained glazing and EPDM gaskets support dependable performance across changing UK weather. Triple glazing can achieve indicative Uw values from 1.1 W/m²K, while acoustic performance can reach Rw 44 dB depending on the glass specification.
Features and performance
- Ultra-slim thermally broken aluminium profiles
- Three external profile styles
- Suitable for contemporary work and steel-window replacement
- Double- and triple-glazing options
- Secured by Design accreditation
- Dual-colour and anodised finishes
Technical specifications
Colours and finishes
Colours and finishes
One colour, or two.
The aluminium profiles are polyester powder coated or anodised, in a full range of finishes. Dual colour construction lets the inside differ from the outside.
Outside
- Material
- Aluminium
- Finish
- Polyester powder coat, or anodised
Inside
- Material
- Aluminium
- Colour
- The outside colour, or a different one with dual colour
Choose by RAL reference
Powder coating comes in a full range of colours. Browse the RAL Classic range and add the colours you have in mind.
Your selection
Colours on screen are a guide only, and pearl and metallic finishes cannot be shown. Add your choices to your project enquiry and we will go through them with you.
Add to project enquirySource: Zyle Fenster’s specification and FAQs for this system.
Gallery
FAQs
Common questions, answered.
The essentials on the Reynaers Ultra Slim SL38: what it is, how it performs, the options, and where it fits best.
Still have a question?
Our team can talk you through the detail for your project.
Why is SL38 described as ultra slim?
Its minimum visible combined frame-and-vent width is 67 mm, providing unusually narrow sightlines for a thermally broken aluminium system.
Can SL38 replace existing steel windows?
Yes. Its restrained profiles make it suitable for steel-window replacement where better insulation, weather resistance and acoustic comfort are required.
What U-values are available?
Indicative Uw values start from 1.4 W/m²K with double glazing and 1.1 W/m²K with triple glazing, subject to the final configuration.
Is the system available in dual colour?
Yes. Different internal and external powder-coated or anodised finishes can be specified.
Is Secured by Design available?
Yes, when the system is specified in a configuration meeting the relevant Secured by Design requirements.
Downloads
Drawings and technical data.
3 files for this system, published by Zyle Fenster. Tell us who you are once and everything here opens for the rest of your visit.
Datasheets 2
Specification sheets and technical data
CAD drawings 1
DWG section details for drawing packages
Before you download
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