ALUK Optio Flush Casements

Flush Aluminium Windows

  • Modern Flush Casement Design
  • Slim 45mm sash
  • Polyamide Thermal Break Technology
  • Energy Rated 'B'

ALUK 58BW flush aluminium windows

Achieve minimal sightlines and maximum weather resistance with 58bd flush aluminium window

The 58BW flush window combines minimal sightlines and maximum weather resistance with all the best features of the tried and trusted 58BW range: advanced performance, versatility and security.

Flush slimline aluminium windows

A flawless, flush finish and slim sightlines make this the perfect choice for contemporary new build and refurbishment projects.

With a choice of slim sashes and a range of window configuration options, the 58BW Flush can be used to achieve a sleek, minimal aesthetic to suit any project.

Aluk 58BW Flush Casement Profile

Flush innovation

  • Advanced weather performance – features like the double rebate, and friction stays on side-hung windows offer protection against bad weather conditions
  • Slimmer sightlines – 45mm ultra-slim sash suits a range of property styles
  • Flexible design choice – the flush shadow line can be complemented with a choice of flat, putty line or stepped edge vent styles to suit the property
  • Safe and secure – tested to PAS 24 and certified under the Secured by Design scheme
  • Energy Rating – Energy Rated B

Performance and accreditations

  • U-Value (Double Glazing) (Ug: 1.0 W/m2K) 1.5 W/m²K
  • Window Energy Rating (WER) B-C
  • Air Permeability Class 4 (600 Pa)
  • Water Tightness Class 9a (600 Pa)
  • Wind Resistance Class E2400 (2400 Pa)
  • Acoustic Performance Rw (C;Ctr) 42 (-1;-5) dB
  • Security PAS 24 & SBD
  • Profile Depth 70mm
  • Glazing Options Internal Bead
  • Glazing Thickness 24mm – 35mm
Aluk 58BW Flush Casement Diagram

Two frame heights

43 Mm Frame Depth
53 Mm Frame Depth

Upgrades/Options (Extended lead time)

Sashes – Puttyline sash, Stepped sash and Externally beaded sash

PAS 24 / Doc Q

‘A’ Rated

Handles – A range of cranked handles

Colour Range

For fast delivery



RAL 9910hg

Anthracite Grey

Anthracite Grey

RAL 7016m

Anthracite Grey White

Anthracite Grey / White

*Open out only

Available in any RAL colour

Available in a range of Single and Dual RAL Colour finishes


White Cranked Handle



Contact us on 01536 271940 or fill out our Online Enquiries Form