Where a box sash window has been converted to a different style we can reactivate this to a fully functioning double glazed sash window.


Over the years many box sash windows have undergone various conversions such as fitting upvc, aluminium, louvre, pivot or casement window sub-frames. Fortunatley the original box frame is often left intact and we can undo the conversion to reactivate them into a fully functioning double glazed sliding sash window.

After removing the existing window conversion we fit a balance system including new pullies, cords & weights. We undertake repairs and install our authentic replica wooden sashes into your existing timber frames, paint finished and double glazed with energy efficient (low E) glass.

All of our draught seals are designed to be as unobtrusive as possible, being machined into the timber components to become an "invisible" part of the window.  The original heritage appearance of the property is restored with all the benefits of modern windows

If the original box frame has been removed then a complete window replacement will be required. 


Georgian sash window.

Georgian Double Glazed sashes.
Reactivating a box sash window to its original vertical sliding design.


Our Sash Reactivation Service includes:

  • Survey of the existing frames
  • Removal of the unwanted conversion
  • New Weight System installed
  • Our standard Restoration & Draught Seal service.

  • Bespoke replica timber sashes
  • Balancing the weighting mechanism, to ensure ease of operation.
  • Large selection of double glazed units.
  • A choice of paint finishes.
  • A wide range of ironmongery in a choice of finishes.

Double Glazed Replica Victorian Sash.



sash window castellated double glazed sash.


Authentic Wooden Replicas


We carefully reproduce a copy of the original sashes using any photos you might have or referencing a neighbouring property. By increasing the rebate depth we accommodate a sealed double glazed unit.

Glazing bars can be either bonded with duplex bars or individual Slimlite sealed units.

Offered in a wide range of timbers inc. Meranti,Oak,Sapele, Douglas Fir, Accoya™.


Large selection of Double Glazed Units (DGU) :

  • 5 - 16 mm spacer bars depending on the sash thickness.
  • Slimlite DGU or duplex bars

  • Acoustic DGU configuration
  • 'Low E' energy efficient glass
  • Etched or patterned glass.
  • Safety Glass
  • Argon filled for better energy efficiency
Double glazing for heritage windows.


UK - FENSA, Document L & The Building Regulations?