What Is Glazing?
Glazing is the term used to describe the glass that is fitted into windows and doors. Glazing acts as a barrier between the inside and outside of a building, helping to insulate your home, reduce noise and provide safety.
What Is Single Glazing?
Single glazing refers to a window that has only one pane of glass in its frame. This is quite common in older properties in Edinburgh. Single glazing is known for its poor thermal insulation and allows sound to pass through more easily into your home.
What Is Double Glazing?
Double glazing consists of two panes of glass with a space in between, which is usually filled with air or an inert gas like argon. This design enhances insulation and reduces noise from the outside. Additionally, the effectiveness of double glazing can be further improved by using varying thicknesses of glass.
Can Sash Windows be Double Glazed?
Yes, it is very common for sash and case windows to be double glazed. At Eco Sash and Case, all our new windows are fitted with heritage double glazing, preserving the charm while improving insulation.
If your existing sash frames are in good condition, we can also retrofit double-glazed units into them. This allows you to upgrade your existing window without having to fully replace them. However, please note that not all windows are suitable for this approach. Older frames may be too fragile to handle the extra weight of double glazing, meaning a full replacement would be the better option. If you are interested in finding out more about this service, please get in touch.
Is Double Glazing Allowed in Listed Buildings?
In Edinburgh there is a high volume of properties in listed and conservation areas. Listed building consent is usually required for any changes that affect the character of the property which also includes replacing single-glazed sashes with heritage double glazing.
In many cases, receiving approval for heritage double glazing isn’t an issue, as it improves home efficiency. Planning does require heritage double glazing, which is made with ultra-thin sealed units designed to mimic the look of single glass. While our standard glazing option is 12mm we offer upgrades to 16mm which in most cases is approved by planning but does need to be stated in the application.
How Much Does Double Glazing Improve Energy Efficiency in Sash Windows?
The exact improvement depends on the glass thickness and window condition an but on average single-glazed sash windows often have a U-value of around 4.5–5.0 W/m²K (higher value = worse insulation).
Whereas double glazing can bring that down to 2.5–1.6 W/m²K, cutting heat loss by more than half.
Double glazing helps to lower heating bills in winter, and offers a more comfortable home all year-round. If your window sashes are also draught-proofed, this will make the improvement even more noticeable.
What are the Alternatives to Double Glazing for Sash Windows?
As an alternative to double glazing, we can also offer secondary glazing. Secondary glazing is a discreet internal frame fitted in front of the original sash, leaving the external appearance untouched.
