Casement vs Sash windows
James Elston

James Elston

Published March 16, 2025

Last Updated on March 17, 2025

Casement vs Sash Windows: Which Style Is Right for Your Home?

When it comes to choosing the right windows for your home, understanding the differences between various window styles is crucial. Among the most popular choices for UK homes are casement and sash windows. 

Each of these window types has its own unique set of advantages, depending on your property’s needs.

In this comprehensive guide, we will explore the key differences between casement vs sash windows, along with expert insights to help you decide which is the best fit for your property.

Casement vs Sash Windows: Key Differences

How do Casement Windows Work?

Casement windows are hinged at the side or top, allowing them to swing outward when opened. The mechanism is typically operated by a handle or a crank. Casement windows open fully, providing maximum ventilation and airflow, especially if they are hinged at the side (side-hung). 

These windows are known for opening to a 90-degree angle, ensuring a wide opening for fresh air.

Pros and Cons of Casement Windows

Pros
  • Excellent ventilation – Full window opening allows for better airflow.
  • Energy-efficient – Provides an airtight seal when closed, reducing heat loss.
  • Enhanced security – Multi-point locking systems offer better protection.
  • Lower maintenance – Fewer moving parts compared to sash windows.
Cons
  • Limited design options – Not as aesthetically diverse as sash windows.
  • Can obstruct outdoor spaces – Windows opening outward may interfere with pathways.
  • Weather exposure – Hinges and seals may require maintenance over time.
  • Not always suitable for period properties – May look out of place in traditional homes.

Casement Window Variations

Casement windows come in several variations, each catering to different needs and preferences:

  • Side-Hung Casements: Hinged at the side, they open outward like a door, providing maximum ventilation.
  • Top and Bottom-Hung Casements: These casements are hinged at the top or bottom, opening like a tilting window, ideal for upper floors or rooms where space is limited.
  • Single and Double Casements: Single casements have one hinged sash, while double casements have two sashes that open outward, offering greater flexibility and ventilation.
  • Flush Casements: These casements sit flush within the frame, providing a sleek, modern look with minimal protrusion from the wall.
  • Fixed Casements/Picture Windows: Fixed casements do not open but offer expansive, uninterrupted views and maximum light.
  • Timber Casement Windows: Traditional and attractive, timber casements offer a natural look but may require more maintenance.
  • UPVC Casement Windows: A more modern, low-maintenance option that provides energy efficiency and security.

How do Sash Windows Work?

Sash windows operate differently, typically sliding vertically (though some are horizontal). The most common type is the double-hung sash window, where both the top and bottom sashes slide up and down. 

Sash windows usually do not open as widely as casements but provide moderate airflow depending on how much the sashes are raised. The sliding mechanism can also be operated via a cord and pulley system in older models or spring balances in modern designs.

Pros and Cons of Sash Windows

Pros
  • Classic aesthetics – Ideal for period properties and listed buildings.
  • Space-saving design – Since they open vertically, they don’t obstruct exterior areas.
  • Increased ventilation control – Allows for top and bottom opening to improve airflow.
  • Adds value to heritage homes – Maintains the authenticity of period buildings.
Cons
  • Higher maintenance – Moving parts require regular upkeep.
  • Can be less energy-efficient – Traditional single-pane designs can cause heat loss.
  • More expensive than casement windows – Higher manufacturing costs due to design complexity.
  • Security concerns – Older sash windows can be easier to force open.

Sash Window Variations

Sash windows also come in a range of styles suited to different property types:

  • Georgian Sash: These windows feature distinct grids in the glass, giving them a classical and elegant appearance.
  • Half Georgian Sash: A variation of the Georgian style with fewer grid bars, offering a simpler, yet refined look.
  • Victorian Sash: Often characterised by large panes of glass, Victorian sash windows were designed to maximise light and ventilation.
  • Edwardian Sash: Featuring broader frames and often larger glass panes, these sash windows bring in more natural light and add a sense of grandeur to a home.
  • Timber Sash Windows: Traditional and charming, timber sash windows are suitable for period properties but may require regular upkeep.
  • Sliding Sash Windows: The classic sliding mechanism allows you to open the window vertically without needing to swing it outwards.
  • Double-Hung Sash Windows: This design allows both top and bottom sashes to move, offering increased ventilation and ease of use.
  • Aluminium Sash Windows: Offering a more modern alternative to timber, aluminium sash windows are low-maintenance and provide superior insulation.

Aesthetic Appeal and Suitability for Property Types

The choice between casement and sash windows is heavily influenced by your property’s architectural style and the overall look you want to achieve. Both window types offer distinct aesthetics that can enhance or detract from a home’s appearance depending on the era and design of the building.

Casement Windows: Sleek and Contemporary

Casement windows are commonly found in modern homes, new builds, and energy-efficient renovations due to their clean, simple lines and practical design. Their outward-opening mechanism and large glass panes give homes a more open and airy feel, maximising natural light.

Best suited for:

  • Contemporary homes – Their minimalist style complements modern architecture.
  • New builds and extensions – They blend seamlessly with today’s construction trends.
  • Energy-efficient homes – Their airtight seal improves insulation and lowers energy consumption.
  • Bungalows and flats – Casement windows offer ease of use and excellent ventilation.
  • Visual impact: Casement windows create a modern and functional look, often available in uPVC, aluminium, or timber with a variety of colours and finishes.
  • Limitations: While versatile, casement windows can look out of place on period homes unless designed with heritage-style detailing (e.g., timber frames or Georgian bars).

Sash Windows: Classic and Timeless

Sash windows are synonymous with Georgian, Victorian, and Edwardian properties, where their traditional charm and vertical sliding mechanism complement period architecture. Many listed buildings and conservation areas require sash windows to maintain historical accuracy.

Best suited for:

  • Georgian and Victorian homes – Maintains the original character of historic buildings.
  • Edwardian properties – Blends seamlessly with early 20th-century architectural styles.
  • Conservation areas and listed buildings – Often a requirement to preserve historical integrity.
  • Cottages and townhouses – Their space-saving vertical opening makes them ideal for homes with limited outdoor space.
  • Visual impact: Sash windows exude elegance and sophistication, with options in timber, uPVC, or composite materials to mimic traditional designs while offering modern energy efficiency.
  • Limitations: While sash windows are beautiful, they often come with higher costs and maintenance requirements, especially if opting for authentic wooden frames.

Which Window Type Lets in More Light?

Casement Windows

Casement windows offer an unobstructed view when open or closed, allowing for a greater amount of natural light to enter the room. Since the entire window is generally clear of structural elements (such as vertical and horizontal bars), the glass area is maximized.

Sash Windows

Sash windows typically have more frame structure in place due to the sliding mechanism and the double sashes. While sash windows can still allow plenty of light into the room, they may be slightly less effective than casement windows in terms of the total glass area.

Which Window Provides Better Airflow?

Casement Windows

Casement windows excel in ventilation. As they swing wide open, they allow for increased airflow, even on windy days, making them an excellent option for homes that require good ventilation. 

Side-hung casements, in particular, provide excellent control over how much air is allowed inside.

Sash Windows

Sash windows offer ventilation but not as effectively as casement windows. Double-hung sash windows allow airflow from the top and bottom sashes, but the amount of ventilation is somewhat limited compared to the wide opening of a casement window. 

However, they still perform well in moderate weather conditions.

Draught Proofing: Which Window Is More Energy-Efficient?

Casement Windows

Due to their design and full sealing capability, casement windows are typically more energy-efficient. When closed, they seal tightly around the frame, which reduces the chances of draughts entering your home. 

Many modern casement windows are equipped with weatherstripping to enhance their draught-proofing.

Sash Windows

Sash windows, especially older timber models, can be more susceptible to draughts due to the gaps between the sliding sashes. However, modern sash windows, particularly uPVC or aluminium models, are designed to offer better draught-proofing and energy efficiency.

Which Window Style Is Safer?

Casement Windows

Casement windows are typically more secure than sash windows. The locking mechanism on casement windows is often built into the frame, making it harder to tamper with. 

Additionally, the full closure of casement windows creates a tighter seal, providing added security.

Sash Windows

While sash windows can be secure, older models may be more vulnerable to being forced open. Newer sash windows with modern locking mechanisms can be just as secure as casement windows, but their design is often less inherently secure than a casement window.

Which Window Is Easier to Maintain?

Casement Windows

Casement windows are relatively simple in terms of design and maintenance. They are easy to clean as the window can open fully, allowing you to access both sides of the glass from indoors. 

The hardware (handles, cranks, or hinges) may require some maintenance, but these windows are generally low-maintenance overall.

Sash Windows

Sash windows can be more complex due to their sliding mechanisms, pulleys, and cords, especially in traditional timber models. They may require regular maintenance to ensure the sashes move smoothly and the weatherstripping remains intact. 

However, modern designs have simplified the maintenance process.

Casement vs Sash Windows: Cost Comparison

The cost of new windows depends on several factors, including the materials used, glazing options, installation complexity, and ongoing maintenance. Below, we’ll compare the average prices of casement and sash windows to help you make an informed decision.

Casement Windows: More Affordable Option

The cost of casement windows are generally more budget-friendly due to their simpler design and construction. They typically have fewer moving parts, making them easier and cheaper to manufacture and install.

  • Average Cost: Basic uPVC casement windows start from £300–£600 per window, while premium aluminium or timber versions can range from £800–£1,500.
  • Installation Costs: Since casement windows are simpler to fit, labour costs tend to be lower compared to sash windows.
  • Long-Term Savings: Their airtight seal improves energy efficiency, reducing heat loss and potentially lowering energy bills over time.

Are Sash Windows More Expensive than Casement Windows?

The cost of sash windows are typically more expensive due to their intricate design, additional moving parts, and traditional aesthetic appeal. They require expert craftsmanship, especially when made from high-quality timber or when replicating historical designs for conservation areas.

  • Average Cost: uPVC sash windows start from £600–£1,000 per window, while premium timber or heritage-style sash windows can cost £1,500–£3,000+ each.
  • Installation Costs: Due to their weight and complexity, sash windows require skilled installation, which can add to the overall cost.
  • Long-Term Considerations: Wooden sash windows require ongoing maintenance (painting, sealing, and repairs), adding to lifetime expenses. However, modern double-glazed sash windows offer better insulation, potentially reducing heating costs.

Which Type of Window Is Best for Your Home?

  • Casement Windows: Best suited for modern homes or properties that require excellent ventilation and security. They’re ideal for homes with larger openings or those in need of greater airflow.
  • Sash Windows: Perfect for period properties or homes where maintaining a classic aesthetic is important. They offer charm and elegance but may require more maintenance.

If you’re unsure which style suits your property best, don’t hesitate to get in touch with us for expert advice.

Comparing Casement Windows to Other Styles

If you’re considering casement windows but want to explore how they compare to other popular window styles, here’s a breakdown of key differences:

  • Flush windows vs. casement windows – While both offer a sleek appearance, flush windows sit perfectly level with the frame, creating a modern, seamless look, whereas casement windows protrude slightly when closed and offer better ventilation.
  • Casement vs. double-hung windows – Double-hung windows have two operable sashes that slide vertically, making them ideal for traditional homes, while casement windows open outward for better airflow and energy efficiency.
  • French windows vs. casement windows – French windows function similarly to casement windows but have a double-panel design without a central frame, offering an unobstructed view and a classic aesthetic.
  • Casement vs. fixed windows – Fixed windows do not open, making them great for maximising natural light and insulation, whereas casement windows provide both light and ventilation.
  • Casement vs. sliding windows – Sliding windows open horizontally along a track, making them a space-saving option, whereas casement windows swing outward for superior airflow and a tighter seal against drafts.
  • Awning windows vs. casement windows – Awning windows are hinged at the top and open outward, making them ideal for rainy climates, while casement windows, hinged at the side, provide better side breezes and full window openings.
  • Casement vs. tilt and turn windows – Tilt-and-turn windows offer dual functionality, tilting inward for ventilation or swinging open like a door, whereas casement windows only open outward but provide a strong seal for energy efficiency.

Request Your Free Quote for New Casement or Sash Windows

Ready to enhance your home with new casement or sash windows? Request a free, no-obligation quote today! Our expert team is here to help you choose the perfect windows for your property, ensuring style, functionality, and energy efficiency. 

Get in touch now and discover how affordable upgrading your windows can be!

FAQs

Are casement windows better than sash?

It depends on your needs. Casement windows offer superior ventilation, better energy efficiency, and enhanced security due to their multi-point locking system. 

Sash windows, on the other hand, are favoured for their traditional aesthetic, making them ideal for period properties. If you prefer modern performance, casements might be the better option, while sash windows are excellent for maintaining historical charm.

Why do people like casement windows?

People appreciate casement windows for their excellent airflow, ease of operation, and energy efficiency. Their wide-opening design allows for maximum ventilation, and their secure locking mechanism provides added home security. Casements are also available in various styles, including uPVC, timber, and aluminium, offering flexibility in design.

Do sash windows add value?

Yes, sash windows can add value to a property, particularly period homes or heritage properties. They enhance a home’s character and curb appeal while maintaining historical accuracy. 

High-quality timber or uPVC sash windows with modern draught-proofing and double glazing improve insulation and energy efficiency, making them a desirable feature for buyers.

Are casement windows still popular?

Yes! Casement windows remain one of the most popular window styles in the UK. They are versatile, energy-efficient, and available in various materials and designs, from sleek, modern aluminium frames to traditional timber finishes. 

Their practicality and adaptability make them a top choice for both new builds and renovations.

Can someone break into a casement window?

While no window is completely burglar-proof, casement windows are among the most secure due to their multi-point locking system and the fact that the sash locks tightly into the frame. 

High-quality casements with toughened glass, key-operated locks, and internal beading significantly reduce the risk of forced entry.

Are sash windows cold?

Older, traditional sash windows can be draughty if they lack proper insulation or weatherproofing. However, modern sash windows with double glazing, draught-proof seals, and energy-efficient materials provide excellent thermal insulation. 

Upgrading to high-performance sash windows can help retain heat and reduce energy bills.

James Elston

James Elston

Boiler Expert

James Elston is the top boiler replacement and heating expert at Eco Happy. He has over 20 years of experience in the industry, focusing on Gas Safe boiler installations and offering home-heating and energy-saving solutions to homeowners across the UK. From sourcing the most energy-efficient combi boiler to providing specialist heating advice, James ensures that Eco Happy maintains the highest standards and best customer service.

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