The Complete Guide for Double Glazed Sash Windows Cost—Sash Window Repair Cost Guide

Sash windows reeks of royalty as they look super luxurious and beautiful. But, it is believed that they are super expensive and do not insulate your homes. While it’s true with traditional sash windows, modern sash windows—even wooden ones provide better insulation and a classic look to your home.

In this article, we will break down the complete costs for double glazed sash window installation and discuss when you need to replace or repair them.

Check out our article on the Cost of double glazed windows.

The Average Double Glazed Sash Windows Cost

Note: Since sash windows are mostly made of timber wood, the final cost may surprise you. That’s because the wood may need complete restoration or repair on top of the double glazing. Therefore, it is always recommended to consult at least three businesses before making a final decision.

New double glazed sash windows are the most expensive investment you’ll ever make because of the type of wood and glass used in the windows.

The cost of a new double glazed sash window is around $1000 to $3,000 per square meter in Australia. But if you choose to retrofit your windows instead of full window restoration, the amount will be one-third of the average price of installation.

Check out our article on DIY double glazed windows prices.

Common Sash Window Repair Costs

Here are the common sash window repair costs:

Sill Splicing:  If you want to replace certain portions of your window, you can go for window sill splicing which would cost you around $218 – $320 on average.

Sill Replacement: If you want to replace the window sill, the cost would be around $175 to $300 on average.

Sash Replacement: If your frames are in pristine condition, you may just want to replace the wooden sash. The cost of sash replacement is around $250 to $400.

Sash window restoration: If you don’t want to throw away your windows, you can just replace them with a new design with sash window restoration. This would cost you around $650 to $950.

Factors that Affect Double Glazed Sash Window Cost

The average cost of double glazed sash window depends on the following factors:

Window Profile

The most important factor that determines the final cost of installation is your window profile. There are various materials that differ in cost. For example, uPVC (the cheapest), aluminum, and timber (the most expensive).

If you’re someone who would like to maintain the traditional look of your sash window at reasonable costs, we suggest getting wood grain uPVC sash windows. It costs less, provides more convenience, is easy to maintain, and never needs repainting.


It may sound trivial, but color plays a major role in determining the final cost of double glazed sash windows. The cheapest color for windows is white. However, if you want other colors, be prepared to pay at least 40% more.

Also, if you want a particular finish of the color, for example, a wood grain effect, it would cost you more.

Window Style

If you have older windows and want to restore them, the framing and glass replacement costs will be additional. Also, if you want to add designs or other decorations to your windows, the price will vary accordingly.

Window Size

The size of your sash window directly influences the average cost of installation. The larger the window, the higher the costs.

Number of windows

The number of windows largely influences the price of replacement. If you wish to replace all the windows at a time, some businesses might offer you amazing discounts.

Glass Thickness

The thickness of the glass affects the real cost of installation. You may choose single, double, triple, or frosted glass according to your preference and the prices may vary.

Window Installation

The total price of window installation depends on the number and size of your windows. The more time-consuming the process, the costlier.

The total cost also depends on whether you’re installing new windows or replacing existing ones. The removal of sash windows is expensive and tiring. Therefore, the total price of installation depends on how many replacements are required.

There are various double glazing companies that offer discounts and competitive prices. However, we suggest considering reviews and accreditations before making a final call.

Your Location

Lastly, your location matters. If you’re based in Melbourne the price of windows will be higher due to higher living costs than in Box Hill.

How is a Modern Wooden Sash Window Different from a Traditional Sash Window?

Unlike traditional sash windows, the modern wooden sash is framed with wood of premium quality. It is also properly treated and weatherproofed, precisely beveled, and neatly finished. In short, they give your house a modern treatment while maintaining their old school aesthetics.

Above all, they are soundproof, weatherproof, impervious to heat differentials, and everything else. That’s because they are equipped with twin panes of high-tech glass that are designed to block all external noise while allowing internal noise to pass through.

Additionally, unlike traditional sash windows, in the summer, these modern sash windows keep the heat out and let the cool air in. While in winter, it takes care of all your heating needs.

As far as the cleaning is concerned, you need no ladder to clean your windows inside out. The wooden sash windows can be removed from their frame through a small click lock. This lock also allows you to replace any broken window affordably without harming the wall or any other house property.

Essentially, the problem with older sash windows was the falling sash. Modern sash windows come with coiled springs, block, and tackle balances to ensure smooth operation and exceptional holding. Therefore, in terms of appearance, the modern sash is beautiful with better glass and functionality, and overall aesthetics.

When to consider replacing Double Glazed Sash Windows?

The life expectancy of professionally installed double glazed sash windows is around 20 years, after which, they need to be replaced. However, sometimes, circumstances may call for early replacement.

That’s because weather conditions directly influence the condition of your sash windows. Especially, if you’re living near coastal areas, your sash windows may not last up to 20 years or so.

So, when to consider replacing your sash windows? Here are some telltale signs:

Your sash windows are damaged or broken

If your windows are broken or damaged, you need to replace them ASAP. Because they not only look awful but also put your home’s security at stake.

Also, the energy efficiency of your sash windows is greatly compromised if they are broken.

Some glaziers might recommend repairing them, but repairing them will only cause new issues. Therefore, it is advisable to get your damaged or broken windows repaired immediately.

There are draughts

If your home takes a lot of time to warm up, even after turning on the heating, it’s high time to replace your sash windows.

The draughts are mostly caused by windows that are either single glazed or not properly sealed, which requires immediate attention. When this happens, all the heated air immediately escapes outside, increasing your energy costs.

Therefore, it’s important to replace your sash windows to fix the drought issues and lower your energy costs.

You are upgrading your home

Homeowners mostly replace their sash windows when their home is undergoing a major update.

It is an excellent time to get your sash windows replaced because you can match the style and theme of your windows with your home, resulting in a house that is fashionable outside and cozy inside.

There are condensation problems

If you notice condensation on your windows first thing in the morning, it’s time!

Condensation is disgusting. It causes the wood around your windows to decay, causing moisture in the air that may result in mold, which is hazardous to your health. Overall, condensation is the ultimate sign to replace your sash windows because they are not functioning well.

There is sudden noise pollution

When you suddenly face the issue of noise pollution, it’s a surefire indicator that your sash windows are faulty and need to be replaced.

 This problem will be more obvious in busy urban regions and populated neighborhoods.

Benefits of Double Glazed Sash Windows

Noise reduction: The two panes of glass in the double glazed sash windows are pressed up against one another to block out cold air as well as external noise. This is specifically helpful for people living on a busy road or under a flight path.

Increased security: Unlike traditional sash windows, the modern double glazed windows feature stronger locks that are much safer and cannot be forced open under any circumstances.

Reduce pollution: The double glazed units fit perfectly together and restrict pollutants from entering your home just like they stop the movement of heat from inside to outside and insulate your home.

Aesthetics: The design of double glazed sash windows is universally compatible and goes well with most houses. Therefore, it’s the first choice of homeowners. Comparatively, other window types, such as PVC or metal frames look slightly off.

Environmentally friendly: They retain heat considerably longer than conventional windows, requiring less fossil fuel to maintain a comfortable indoor temperature.

Saves energy: You will save a lot of energy and money as there will be low power consumption in your home.

How to Care for Wooden Double Glazed Sash Windows?

Wooden sash windows have been with us forever—in high-end restaurants, homes, offices, and even hospitals. Fortunately, the modern sash windows allow you to add insulation properties alongside their classic style statement, especially during the winters when you need insulation the most.

However, if they are not maintained and kept properly, they won’t function at all, wasting all money and energy.

Therefore, to keep them working properly, regular maintenance and upkeep is required.

Luckily, the maintenance of double glazed sash windows is not a daunting process. Just quick fixes and daily cleaning.

Here are some tips to keep your windows in good shape:

  1. Regularly clean the wood and glass and look out for damage such as paint peeling, decay, or water damage.
  2. Use high-quality wood paint to treat the wood every 3 years to protect against weather damage.
  3. Avoid using lead based paints on your double glazing.
  4. Remove any peels and chips on your windows before painting by using sandpaper.
  5. Once the windows are smoothened up, apply a thin coat first to see if there are any chips remaining. Continue painting a couple of coats to ensure the wood gets maximum protection.
  6. Always paint your windows when the Sun is out and there are zero chances of rain.
  7. Remember to remove sashes from the window frame before painting.
  8. You can paint every 5 years and sooner if you notice any wear and tear.
  9. Look out for leakages in your windows by closing the curtains and keeping an eye out for movement. Also, you can light a match or a lighter and carefully move it around the window’s edges and center to observe if the flame moves.

Final Thoughts

It’s true that the average cost of double glazing sash windows is high, but the advantages it offers overweighs everything. Therefore, you should at least consider getting your sash windows double glazed to enjoy the perks of long-term cost savings on energy bills and maintenance.

Now that you know the total cost of double glazed sash windows is $1000 to $3000 depending on various factors, it’s time to find a reputable business that caters to your needs. Remember to take quotes and compare prices from at least three companies before making a final decision to get the best offer.


How Much Are Sash Windows?

The total price of sash windows depends on various factors, including frame, glass type, number of windows, size of windows, glass thickness, etc. The average cost of double glazed sash windows is around $1000 to $3000 per window.

Can Sash Window be Double Glazed?

Yes, sash windows can be definitely double glazed. In fact, double glazing is a great way to improve your home’s thermal performance and reduce noise pollution. The outstanding benefits of double glazing are a reason why double glazed sash windows are getting popular in Australia.

Are double glazed sash windows more expensive?

As compared to single glazed windows, double glazed sash windows are more expensive because it adds a second pane of glass to a window that creates an insulating air space between the two panes of glass.

Can you double glaze existing sash windows?

Yes, you can double glaze existing sash windows only if the condition of your windows is top-notch. The possible methods to double glaze your existing sash windows are:

  1. Retrofit double glazing
  2. Secondary double glazing
  3. Sash window replacement

Why are sash windows so expensive?

Sash windows are expensive because of the materials used in the manufacturing of these windows and labor costs. Ideally, the materials used in sash windows are hardwoods like oak or mahogany with high-grade premium glass. These materials are more expensive than other window types.

The labor costs of sash windows are also exceptionally high because they are usually handmade by skilled craftsmen.

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