Period houses that still feature their original old sash windows will look to improve them at some point. Which is understandable because over time a single-glazed window will not produce the highest levels of energy efficiency.

But improving your old sash windows doesn’t mean you have to replace them with a different style entirely. There are a number of different options available that will allow you to retain the original aesthetic and also improve the energy rating. We go into more detail about what you can do below.

Double glazed or triple glazed

One of the most common ways to improve old sash windows is to replace the existing single glazed panes with either double or triple glazing. Of course, initially it seems as if triple glazing would always be the best choice as it offers more protection, but depending on the property’s architecture, this is not always the case.

Double glazing features two panes of glass, while triple glazing has three. A professional installation company should be able to determine what type of glazing is best for the overall structure of the window and the energy efficiency of the room it is installed in.

However, in general terms, triple glazing does offer high levels of energy efficiency. For example, in a room heated to 21 degrees, the internal surface temperature of double glazed windows is 16 degrees (single glazed is a terribly low 1 degree). The lower the temperature, the more condensation will develop inside of the pane which eventually creates damp and mould.

When triple glazing is also tested in a room heated to 21 degrees, the internal surface temperature of the window is higher than double glazing at 16 degrees.

Are triple glazed windows expensive?

The answer to this question is relative to your budget and what you can afford. Of course, there is a structural difference between double and triple glazed windows which means one costs more than the other. This is because an extra pane of glass is required and there is also an additional chamber to fill with Argon gas.

However, the price difference between the two generally is not too wide. Whether you think it is too expensive will come down to how far your budget is able to stretch. And remember, even if you pay more for triple glazing, the long-term savings on energy bills could actually save you money in the long run.

When to use Argon gas between the glass 

Argon gas plays an essential role in maintaining the energy efficiency of double and triple glazed windows. In order to ensure you can enjoy the full benefits of these types of glazing, Argon gas should always be used.

The reason why it helps to improve insulation is because Argon gas is denser than air. If it is used with a special low-E (low emissivity) glass coating, this helps to bring the temperature closer to that of the window. In turn this removes drafts and air currents that typically occur when different temperatures meet each other.

When you are looking at replacing old sash windows, or considering renovating your home, it is worth giving consideration to Argon gas-filled windows. There are other alternatives available to help improve energy efficiency, but this is commonly thought of as being the most efficient and cost effective long-term.

Replacement double glazed sash windows using an existing frame

If you have single glazed sash windows in your home you may be weighing up the possibility of replacing them with new double glazed alternatives. They tend to be installed in older period properties built before, or shortly after, World War II and may not provide the best levels of energy efficiency in your home.

You may also be thinking about removing the sash windows completely and replacing them with modern, synthetic frames. However, this will not only remove character from the property, but it will also mean the building will lose market value as some of its original features are being removed.

So the question is, can you install double glazing in existing sash window frames? The short answer is yes, but it will also depend on the condition of the original frames. In most cases timber sash window frames can be repaired or refurbished.

A sash window expert – like Repair-A-Sash – can assess the current condition of your sash window frames and offer detailed advice on whether double glazing can be installed in the frame. It is rare that double glazing cannot be installed in existing timber sash windows, but clear advice should be provided as to why this is not possible.

Sash windows services in London  

Over the years Repair-A-Sash have helped countless customers right across London to repair, maintain and modernise their sash windows. As bespoke timber windows and door specialists we are passionate about the work we do and are always prepared to go the extra mile to ensure our customers are satisfied.

We are both FENSA and GGFI-accredited, and part of the Which? Trusted Trader scheme, giving you every assurance our week meets and exceeds your expectations. No matter what condition your sash windows are in, our team of experts are available to help today.