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New hardwood sash boxes

If you wish to reinstate traditional sash windows into your property, whether they are beyond repair or have previously replaced with non-timber or casement windows. We can supply and fit new hardwood sash boxes complete with double glazed sash windows that replicate the originals.
sash window repair

Is this for you?

  • Have your timber sash windows been replaced with UPVC or aluminium casement windows?
  • Do you want to reinstate the original features?
  • Are your timber sash windows and frames beyond repair?
Inside shot of sash window frames being repaired.


  • A double glazed sash will provide improved thermal performance, will retain heat and reduce noise levels.
  • Our new sash windows will replicate the original window keeping the character and architectural identity of your property.
  • By installing a new sash window where they have been previously replaced you are reinstating the original character features to your home, improving both the aesthetic look of the property and its market value.
  • We increase the depth of our sash boxes to allow us to accommodate a thinker double glazed unit, triple glazing or combining acoustic glass to within a double glazed unit.
  • By installing a new sash window, you have the peace of the mind that all of the joinery is new, spray finished, completely draught-proofed and meets current building regulations.
Outside image of Sash window and front door.

How we do it

We carefully remove the original sashes and sash boxes minimising any disruption to the surround décor.  We will dispose of the original windows.

We then fit the new hardwood or Accoya timber sash box complete with timber double glazed sashes which have been manufactured in our dedicated workshop. The sashes are hung on the traditional system of weights, cords and pulleys.

The new sash windows incorporated an integral draught-proofing system.

The new sash boxes are sealed to the exterior brickwork and new internal architrave and window boards are fitted.

Should any of the surrounding plasterwork have been disturbed during the installation then we will patch this up.

Finally a full set of window furniture and locks are fitted.

Once the work has been completed the installation will be registered with FENSA and you will receive a certificate confirming that your new window is compliant with current Building Regulations.

New sash box case studies

We replaced the old UPVC windows and reinstated original timber sashes to replicate the originals in this beautiful Kingston property

Find out about this new sash and double-glazed casement window project in Twickenham by SashWise, the local sash window experts.

We installed 5 x new double glazed sashes into this pretty Victorian home in Kingston upon Thames.

The original sash windows had been removed from this beautiful Victorian cottage in Twickenham. Our client wanted the windows changed back to their original style.

Our other services

Sash window draught proofing

Servicing and draught-proofing

If your sash windows have broken cords or are stiff or jammed shut then this service will restore them to their original smooth working order.

Georgian sash window

Sash window repair and restoration

We completely and sympathetically restore your windows, so they will look like new without losing any of their original features.

Hardwood double glazed sash windows

New hardwood double glazing

If you do not require complete window replacement we can make new double glazed timber sashes to fit your original box sash frames.

Victorian sash window

New hardwood sash boxes

We can supply and fit new hardwood sash boxes complete with double glazed sashes that exactly replicate your original windows.