Insulating Original Timber Sash Windows

With the focus of energy saving in our homes, European ministers constantly trying to find ways to make our homes more energy efficient its reassuring to know that there is help for period and protected home owners here in the UK.

Many period home is the uk are protected from uPVC windows and fascias so there is a need to find alternative ways of making period homes more energy efficient without losing their splendour and charm.


The Victorian Sash Window Company has perfected a process called E-Seal . E-seal is a sensitive process of introducing delicate fibres and pressure seals into the working areas of sliding sash windows which cause heat loss and draughts without changing the appearance of the window. Because the process is sensitive and discrete conservation approval is easy to obtain, in fact many conservation groups welcome this product as an alternative to uPVC.

Micro Slim Sealed Units

Micro Slim Sealed units are a new concept with a 7mm perimeter seal depth and can be glazed into most single glazed period windows. It is now possible to construct double glazed units with very small cavities or space between the glasses and a 7mm perimeter seal depth. Selected insulating inert gas cavity to obtain U-Values to comply with Building Regulations and comparable or better than U-Values obtained by standard units with much wider cavities.

Micro Slim Sealed units are constructed with a 4mm clear outer pane with a selected cavity of 4mm with selected cavity insulating inert gas, argon and krypton which only performs in smaller cavities, and inner pane of 4mm Low Emissivity glass. The emissivity coating is on the inside face into the cavity and reflects the long wave radiation or heat back into the room. The warm edge technology perimeter spacer incorporated, ensures insignificant differential insulation value between edge and centre of glass.

Today it is necessary for double glazed units to comply with Building Regulation in respect of U-Values which are slightly different between Scotland and England. Micro Slim Double Glazed Units can comply with both these regulations as noted.

  • Building Regulations – Required U-Values
  • 4mm Low E/ Cavity, gas/ 3 or 4mm clear float or reproduction crown sheet
  • Micro Slim plus (Low Emissivity)
  • Single Glazing 5.4 U-Value
  • 3.8mm cavity U-Value 1.9

Both products are extremely efficient and can protect and insulate whilst preserving the character and charm of your period home, either as individual services or a combination of the two.

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