Therma Sash 

Thermally insulated sash windows

With Therma Sash, it is possible to achieve much lower u-values in sash windows and still keep the moulding profiles and glazing bars in keeping with the period of the house.

Recent improvements in technology mean we can make sashes with glazing bars as thin as 20mm, and double glaze them using Therma Sash units, and so dramatically reduce the u-value of the sash, and keep the appearance original.

It is also possible, in some cases, to install Therma Sash units into existing sashes.  A sash that is single glazed, would typically have a u-value of 5 or more.

Using Therma Sash units, it is possible to achieve u-values as low as 1.9, depending on the gas used. When this is combined with our draught proofing system, it dramatically reduces heat loss and increases comfort and usability of the sash windows, and therefore reduce energy bills