Double Glazing

Marvels of modern slim double-glazing

OR £1500 per new window

It’s wonderful thing to have the best of both worlds available to you and your sash or casement windows.
Ventrolla can give you all the marvels of modern slim double glazing, without your windows ever looking anything other than late 17th century splendour. With double glazing you can replace the moving sashes in your existing sash boxes, or have complete new windows made, box frame and all.

Replacing original single glazed sliding sashes or casement sashes with bespoke double-glazed versions means you can get a double-glazed solution without major disruption to the property.


The new replacement sashes are manufactured from the finest timber, the choice of which will depend upon preference and budget. Your Surveyor will be on hand to advice you of the options available.


We use slim double-glazing units, allowing us to manufacture sashes using traditional carpentry methods, including solid ‘through’ glazing bars, instead of ones stuck to the glass, helping to retain the window’s authentic look and feel. If we are fitting brand new double-glazed windows we can recreate the majority of historic and traditional sash window styles.

Replacement Sashes Double glazing specification

Slim 14mm (4/6/4) double glazed units, Planitherm Total+ glass (outer pane) and krypton filled cavity. Centre Pane U-Value of 1.5 Wm²K and Total Window U-Value of 1.8 Wm²K

New Window Double glazing specification

Slim 16mm (4/8/4) double glazed units, Planitherm Total+ glass (outer pane) and krypton filled cavity. Centre Pane U-Value of 1.2 Wm²K and Total Window U-Value of 1.5 Wm²K

Draught proofing

Our draught proofing system, the Ventrolla Perimeter Sealing System (VPSS) is fitted on all new joinery, as standard

Energy efficiencies

Reduced energy costs and up to 30% improvement in energy efficiency thanks to the same draught-proofing, Ventrolla Perimeter Sealing System (VPSS) used on our single pane windows


Complies with Part L of the Building Regulations, although it's worth noting that replacement sashes (not full new windows) is outside of Building Control

PEACE of mind

Enjoy easy future maintenance of your replacement or new double-glazed windows, that not only come with a 5 year guarantee but can also withstand 71 mph winds! All our complete new double-glazed windows come with a FENSA certificate for that extra peace of mind. Visit our ‘contact us’ now page and let us help you make your windows exceptional.