Flush Sash Casement Windows

Flush sash casement windows from Warwick North West’s Innolux range are uniquely flush both internally and externally to deliver end user’s with a wildly impressive looking window that performs great also.

Mechanically jointed to completely eliminate the diagonal weld that can sometimes plague modern window designs, flush sash windows are perfect for properties that care about attention to detail.

Completely smooth finish wrapped in an energy efficient system

Delivering the look of a traditional casement window whilst achieving the new A++ Window Energy Rating with a U-value of 0.7 W/m2K, flush sash windows perform just as great as they look. The modus profile we use for our flush sash windows utilise the first dual material extrusion technology and delivers better heat retention at an affordable price for both trade and consumers.

All of our Innolux flush sash windows are available in double and triple glazed, but are always glazed internally as standard. They serve as a great style for consumers who wish to replace their original timber windows, instantly adding a classic look. Each profile is precision engineered to the highest quality making it perfect for premium projects, conservation areas and self-builds.

  • Internally and externally flush for smooth aesthetic
  • Mechanically jointed to remove corner weld appearance
  • Six chambered profile for increased thermal capability (U values 1.1 – 0.7)
  • A++ Rated for sustainability, engineered from 50% post-consumer recycled PVCu
  • Wide range of colours to choose from including woodgrain foils
  • Manufactured in a range of style sizes including fixed, top hung, bottom hung and side hung


Innolux flush sash windows are specifically designed to rival the clean aesthetics of rival timber systems, utilising high performance PVCu to better retain heat and be more affordable as a result. Providing end users with a traditional profile that can be perfectly matched to any scheme or décor but heritage homes specifically.


Aside from classic white, Innolux slim sash casement windows are available in the following colours: Anteak, Rosewood, Irish Oak, Cream and White Ash. Each colour is effective at delivering a woodgrain aesthetic, being near-indistinguishable from genuine timber.


Warwick North West manufactures quality PVCu casement windows, which are designed to offer increased strength and security. Windows use ERA handles and Nico hinges, as well as ERA espagnolette and Nico shootbolt locking, protecting a property and giving the consumer complete peace of mind.


Innolux flush sash windows are manufactured using double glazed sealed units, with Planitherm Total Plus glass, Thermobar warm edge spacers, and Argon gas. This allows our casement windows to achieve an ‘A++’ WER rating and U-values as low as 0.7 W/m2K, exceeding the Passivhaus standard.