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Purpose made double glazed sashes for replacing original single glazed sashes, giving a double glazed solution without major disruption to the property. Fitted into existing sash box frame.


  • Reduced energy costs.
  • Easy future maintenance.
  • Minimum disruption and redecoration to the property.
  • Perimeter sealing system tested to BS 6375-1 (withstands 71 mph winds).
  • Five year guarantee.

General information

As drawing

As schedule


Supplied sprayed with a high build base coat Teknos 3130 and an anti-stain primer Teknos Antique White, ready for final finishing coat by others


The replacement sashes are manufactured from hardwood

Uniclass 2015 Wood window units (Pr_30_59_98_96)
Specification data
Product Reference

Double Glazed Replacement Sashes


As drawing

As schedule

Glazing -

14 mm double glazed units

4/6/4 units with Argon gas filled cavity.

16 mm double glazed units

4/8/4 units with Argon gas filled cavity.




Glazing bar

Insert requirement, consult manufacturer's literature for more information.

Ventrolla Perimeter Sealing System (VPSS) location




Insert requirement.

Standard product features


The replacement sashes are manufactured from hardwood.


Supplied sprayed with a high build base coat Teknos 3130 and an anti-stain primer Teknos Antique White, ready for final finishing coat by others.


Slim Saint Gobain Planitherm Total+ Glass (outer pane) with dual seal edge technology. The units comply with BS EN 1279 parts 1-6 (however, installing replacement Double Glazed sashes into an existing box/ frame is outside of Building Control).


The sashes are manufactured using traditional carpentry methods, including ‘through solid’ glazing bars, which help to retain the windows authentic feel and look. Another main feature of the slim glazing unit is the reduced sightline of the spacer bar between the two panes of glass.

Ventrolla Sash Removal System (SRS):

To assist with future maintenance and painting, we install our patented Sash Removal System (SRS) that enables both the top and bottom sashes to be removed for redecoration and future maintenance.

Ventrolla Perimeter Sealing System (VPSS):

Includes unique VPSS draught proofing system which has been tested to BS 6375-1, Class 3, and withstand 71 mph winds. The system is fitted by routing grooves into the mid-rail and bottom-rail of the sashes, or within the inner edges of casement windows, to which a pile carrier is fitted and the appropriate size of weatherfin pile installed. New parting beads and staff beads are fitted that also incorporate the weatherfin pile, creating a fully draught-proofed window.

Thermal performance (U-value):

- 14 mm units:

  • Centre pane: 1.5 Wm²K.
  • Total window: 1.8 Wm²K.

- 16 mm units:

  • Centre pane: 1.2 Wm²K.
  • Total window: 1.5 Wm²K.

Product Options


Supplied with hardware, optional finishes and a range of styles are available.

Third party certifications
  • Air permeability: tested to BS EN 12207 Class 3 and BS 6375 (600 Pa), test report 2756 : Weatherfin Pile (Draught proofing) testing
  • Draught Strips (Weatherfin Pile): Tested to BS 7386
  • Hanns Tucker Acoustic Engineers : Sound Insulation: Independently tested by and proven to fall within the 6–10 dB noise reduction range (tested on single glazed sashes)
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