Bespoke sash windows

Most heat in a home is lost through the windows and the roof. There are some simple ways to reduce heat loss, such as improving loft insulation and fitting carpets. There are also various things you can do to improve window insulation and reduce the heat lost through your windows, even if you have traditional sash windows in your property. Find out how to insulate sash windows by following the tips and tricks below.

1. Use close fitting curtains

Close fitting, thick, ready made curtains and blinds will help to insulate your home by preventing the warm air inside your home hitting the colder glass of your sash windows and cooling down, as well as reducing draughts. A pelmet above the curtain rail will also improve thermal insulation even further.

2. Install double glazed sash windows

Heat lost through windows can be reduced using double glazing. In fact, if your sash windows are single glazed, then you’ll be losing up to 20% of your home’s heat through them. With double glazing, the gap between the two panes of glass is filled with gas types which are poor conductors of heat, therefore reducing heat loss and improving insulation.

There are specific considerations when it comes to double glazing for sash windows. At Timbawood, we use particularly dense, inert gases in our double glazing, such as argon, krypton or xenon, which conduct the least amount of heat. This means we can offer slimmer glazing units to give a more traditional, elegant look, and even slimline double glazing, from as thin as 11mm, that looks just like single glazing.

3. Consider the glass type

Different types of glass offer different levels of thermal efficiency. Modern double glazing units include a ‘Low E’ (low emissivity) coating, which reflects heat back into the building and offers far better thermal insulation for sash windows than plain uncoated glass.

4. Use warm edge spacer bars

Sash window hardware

The perimeter spacer bar sits between the two panes of glass in double glazing to hold them apart, and contains desiccant to absorb any moisture which may be in the unit. This spacer bar is often made of aluminium – which is highly conductive and loses a lot of heat.

One way to insulate sash windows is to use warm edge spacer bars, as we do with the ‘Super Spacer’, which is made of a pre-desiccated, structural foam, and can increase the internal edge temperature of the glass by up to 65% compared to aluminium spacers.

Using Super Spacer bars can also reduce noise by up to 2 decibels, or 10%, so will keep your home quieter as well as warmer! Find out more about soundproofing sash windows.

5. Draught proof your sash windows

Draught seals provide insulation for sash windows by helping to prevent draughts coming into your property through the perimeter of your windows, and some perform better than others.

Draught proofing your windows using compression seals instead of brush seals will help improve thermal insulation as well as noise insulation. 

All new sash windows will incorporate draught sealing, to seal the 3mm gap that is needed for the window to operate correctly. Without sealing that 3mm gap, it’s equivalent to leaving a 6 inch diameter hole in the glass. This is a bit like cutting a cat flap sized hole in every window, without fitting the cat flap, to let in cold air and noise.

At Timbawood we specialise in bespoke timber windows and doors for period, conservation and listed properties, including sash windows, casement windows, front doors, French doors, fire doors and bifold doors.

To find out more about how to insulate sash windows and the specialist glazing and draught proofing options for our timber windows and doors, speak to one of our specialists who will be happy to give you further advice.