Sash Window Cost: A helpful guide

Windows flush Sash

Have you been planning to upgrade your windows? If you’ve been taking time to make a decision, perhaps your biggest concern is the cost of each window option like sash and casement windows and wondering if they’re worth the investment. Or chances are, you are struggling to choose what’s the most practical and efficient window option for you.

In this article, we’ll help you weigh in the most cost-effective option between the two and give you a helpful insight into the cost of sash windows compared to casement windows and help you understand the pros and cons of each window option. 

UPVC Sash Window Cost

Perhaps, it’s safe to say that the best selling point of uPVC sash windows is its affordability. Sash windows made of uPVC are generally cheaper than those made of wood common in UK homes. Its price ranges from £300 to as much as £950 if it’s a double-glazed sash type, and the bigger it is, the more expensive it becomes. The area, frame colour, glass designs, special glazing, window energy ratings, and finish and furniture can also influence the cost. And when it comes to colour options, woodgrain effect windows are often 10 to 15% more expensive than the standard white types.

If you want to know how prices differ based on different materials and sizes, it will help if you’d check the table below for the comparison.  

Window material (sash) Average cost per window including materials,installation and VAT
uPVC Sash WindowsFrom £700 to £1,100
Wooden WindowsFrom £1,100 to £1,900
100cm x 50cmFrom 1,200 to £1,500

Cost of Replacing Sash Windows

Some local installers often tailor out the costing for your window design, while some large companies have a fixed price per window to replace sash windows or switch from sash to casement windows. 

Some offer a price range in the region of £100 per window, which is a relatively good price whilst considering in a semi-detached home with three bedrooms and nine sash windows it would roughly come to £900, although its understandable to look for the cheapest option, sometimes the cheapest option might mean the cheapest products, and the cost of replacing the window becomes higher if it needs to be done more regularly, that’s why we advise choosing the right material the first time round, with better quality & more durable windows, better suited for harsh weather & temperature drops.

The estimated average cost of double-glazed uPVC sash windows for a full house will vary based on house design, the number of windows and other factors mentioned above, but the typical price range for every property are the following:

  • For a flat, maisonette or terraced home with four to six windows, the price could range from £2,200 to £2,800.  
  •  For a 3-bed semi-detached property with eight to ten windows, the cost could be in the region between £3,000 to £3,800.
  •  And for a 4-bed detached house with thirteen to sixteen windows, the cost could be around £5,200 to £6,000.

Note: These estimated prices can vary from an installer to another, so if you want to know the exact price, which is necessary for creating a budget plan, it would be best to talk to the local installers to confirm the window cost, including the additional expenses for the extra works needed. 

Difference Between uPVC Sash Windows and uPVC Casement Windows

Both sash and casement windows have advantages and downsides. To help you decide between these two window options, let’s make a side-by-side comparison between sash and casement windows based on nine different factors:

Visual Appearance

Sash windows were widely used in UK homes during the 1700s to the early 1900s; that’s why it is more suitable for traditional Georgian and Victorian houses. But it can also work well with modern properties built with period style design. On the other hand, the casement window’s sleek and unobtrusive look makes it suitable for modern homes, even if it existed long before sash windows were created. 

Casement windows are often tall and narrow and open by swinging out vertically, providing excellent airflow. In contrast, sash windows typically have two panels the open by either sliding up or down or from side to side.  


One of the main culprits of draught and energy loss in your home is the windows. Even the tiniest crack in it can either allow heat to escape your room or let cold air enter in from the outside. Most modern sash and casement windows both contain double-glazed glass to improve heat insulation, so the difference between the two lies at the edge of its frame. 

Casements that fit tightly against the frame when closed and locked often provide better insulation than sash windows, and old sash are known for being leaky because woods rot over time. But good thing, sash windows with uPVC frames are now available, and they are far more energy-efficient than woods. If you think that their appearance might not complement with properties which suit wooden fixtures and frame the most, then the good news is there are wood grain effect uPVC sash windows available in the market now. So, you can have a more affordable option without compromising quality.


When a casement window is open from top to bottom, the air can freely flow into the house, but on a sash window, the available airflow will be cut down because it still has a solid glass covering the top half of it even if you’d push it up. 


Window installation often requires a professional’s intervention, especially if you switch from a window style to another. 

Sash windows are often thicker than casements. Therefore, there will be a 1 to a 3-inch gap on the inside if you’re replacing your sash with a casement and covering that gap will require more plastering work and moulding. 

Ease of Use

Most modern sash windows are fairly easy to open and close, thanks to its spring-loaded balance system. But the casement’s crank mechanism is often easier to operate. Shorter people also won’t struggle to reach it, unlike with sash windows. 


Both casement and sash windows are easy to maintain because when a casement is fully open, it would be a breeze cleaning both sides from the inside and sash windows can also be tilted for quick cleaning access. 


Intruders can’t open the casement windows without breaking the glass. Therefore it provides better security. On the other hand, some sash windows can be pried open using a crowbar. But if both of them are equipped with a multi-point locking system like those casement and sash windows offered in P & J, you can experience optimum security level from both options. 


The location where you would use your window would also matter in choosing between the two. A casement is ideal when there is no obstruction outside the window, but a sash one is more practical if the window opening is next to patios or porches. It can also be a better choice if the house is close to the one next to it because it will not block the walkway between them. 


Although it is possible to add a screen to a casement window from the inside, it can interfere with the look from the inside of the property. In contrast, a sash window can be covered with exterior screens, thus providing a better look from the inside. 

Recap of the Pros and Cons of uPVC Sash and Casement Windows
Advantages of Sash WindowsSuitable for traditional home designsFlat profile suitable next to walkways or patiosCan be cleaned outsideUnobtrusive screenLow maintenanceMore affordableEnergy-efficientAdvantages of Casement WindowsMore energy-efficientSuitable for modern designExcellent airflow when openedMore secureEasier to openEasier to clean from inside
Downsides of Sash WindowsHave less airflow when openedPlanning permission is sometimes necessaryMore costlyDisadvantages of Casement WindowsNot suitable next walkways and patiosDifficult to add screens

Casement Windows Cost

Double-glazed casement windows are often more budget-friendly than double-glazed sash windows. The average price for a casement window can be anything from £300 up to £400, but some installers offer as much as £1,300 in a single window. This cost boils down to the same factors that influence the price of sash type. 

These are the average cost of double-glazed casement windows based on the property type and number of windows that need replacement or a new one. 

  • For a Flat, Maisonette or Terraced property with 4 to 6 windows: £1,200 – £2,4000.
  • For a 3-bed semi-detached home with 8 to 10 windows: £2,400 – £4,000.
  • For a 4-bed detached house with 13 to 16 windows: £3,900 – £6,400.

Other Modern Window Options

Aside from casement and sash windows, several other window options are worth considering if you’re planning to replace the old windows in your home or trying to fit one in your modern house. Some of them are the following:

1. Bay windows – The protruding design of bay windows can help by capturing the extra light and breeze.  

2. Awning – This window option lets you enjoy both the natural light and the breeze while keeping your privacy because it’s often positioned high on the wall. 

3. Louvered – This manually-operated window type can control how much air or light is allowed to pass through. But they’re typically for smaller spaces since draughts and issues can arise. 

4. Sliding – This window type comes with aluminium frames, and they’re available in single, double and multi-operating panels. They’re often the safest choice for decks and walkways. 

5. Bi-fold – This option is more suitable for indoor-outdoor living because it can merge one area into another.

6. Skylight – It’s ideal for introducing natural light to your home. It comes in different variations to suit different roof pitches, elevations and needs. 

7. Picture – This fixed window type is simple but versatile and lets the light in but not the elements. 

8. Geometric – They come in different arches, radius and linear shapes that subtly add visual character to any home. 

UPVC Colour Window Options

UPVC windows aren’t just available in white. There’s a wide range of exquisite uPVC window colours and natural wood grain finishes you’ll love, such as white, cream and black woodgrain. You can also opt for the appealing grey cedar patterns, natural oak, golden oak or rosewood if you want hardwood finish that highlights natural woodgrain’s beauty but with less maintenance. If you prefer contemporary colours for your modern home, then olive-grey, light grey, Chartwell green, anthracite, brown and the likes are the one for you. No matter your home’s theme, there’s always a coloured uPVC window that will look great with your property. 

If you’re looking for cheaper alternatives to window installation or replacement there are ways of doing so on a budget, however, you may need to invest a considerable amount on your windows, upgrading to a double-glazed sash window can save you around £115 a year on your energy bills; thus, it can be worth the investment and will ensure a long lifespan of your new windows and help with the long-term money saving.

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