Casement vs Sash Windows: Which is the Best Option for Your Home?
August 26, 2025 | Homeowner | Written by Nicola Harrison
Choosing between casement and sash windows is one of the most important decisions you’ll make when replacing your home’s windows. Both window styles offer distinct advantages, but understanding their differences will help you make an informed decision.
Whether you’re renovating a period home or updating a more contemporary property, selecting the right window style impacts everything from energy efficiency to kerb appeal. Let’s explore the key differences between these popular window types to help you determine the better option for your specific needs.
What is a casement window?
A casement window is a type of window that opens outward on hinges, typically attached to the vertical edge of the window frame. These windows operate with a simple handle, allowing them to swing open like a door.
Casement windows have been popular since medieval times and were popular in the Tudor period, making them a classic choice for many architectural styles.
The design features a single pane of glass or astragal bars can be incorporated to replicate the appearance of multiple individual panes of glass, depending on your preference.
What is a sash window?
A sash window consists of movable panels (called sashes) that slide vertically or horizontally within the window frame. Traditional sash windows feature two sashes that move independently, allowing for flexible ventilation options.
Dating back to the 17th century, sash windows became synonymous with Georgian and Victorian architecture. Modern sash windows maintain this elegant look while incorporating contemporary materials and energy-efficient glazing technologies.
The classic design typically features astragal bars to replicate the look of smaller panes of glass and a distinctive grid pattern associated with period homes. However, modern sash windows can also accommodate larger glass panes for a more contemporary appearance.
Are there different types of casement and sash windows?
Both casement and sliding sash windows have various design variations within their styles to allow you to customise your windows further.
Casement window styles
Flush casement windows: These sit flush with the window frame when closed, creating a clean, streamlined appearance that works well with modern homes and contemporary architecture.
Lipped casement windows: Also called stormproof casement windows, these feature a lip that overlaps the frame, providing better weather protection and a more traditional look that suits period properties.
Sash window styles
Cords and weights: Feature the classic vertical sliding mechanism with counterbalance weights hidden within the frame.
Spiral balance: Incorporate contemporary materials and spring-loaded mechanisms for easier operation while maintaining the traditional aesthetic.
The benefits of casement windows
Superior energy efficiency
Opening casement windows create an excellent seal when closed, as the sash presses against the frame. This tight seal contributes to higher energy efficiency, reducing heat loss and lowering energy bills.
Excellent ventilation
Casement windows can open fully, allowing maximum airflow into your home. This makes them ideal for catching a fresh breeze and providing good ventilation, especially in kitchens and bathrooms.
Unobstructed views
With larger panes of glass and minimal framework, casement windows offer clearer, unobstructed views of your garden or surrounding landscape.
Easy maintenance
The ability to open casement windows fully makes cleaning both sides of the glass from inside your home much easier, reducing maintenance requirements.
Modern appearance
Casement windows suit contemporary homes perfectly, offering clean lines and a modern design that complements various architectural styles.
The benefits of sash windows
Timeless aesthetic appeal
Sash windows provide a unique charm that’s particularly suited to period homes. Their classic look adds character and maintains the authentic appearance of Georgian, Victorian, and Edwardian properties.
Space-saving design
Unlike casement windows, sash windows don’t project outward when opened, making them ideal for properties with limited external space or where windows face walkways.
Flexible ventilation control
Traditional sash windows allow you to control airflow precisely by adjusting the position of both sashes. Opening the bottom of the window slightly and the top creates natural air circulation.
Heritage compatibility
For listed buildings and conservation areas, sash windows often represent the better choice as they maintain the property’s historical integrity while meeting modern performance standards.
Natural light
The vertical design of sash windows maximises natural light, particularly beneficial for rooms with limited window space.
Casement vs sash: energy efficiency comparison
When comparing casement vs sash windows for energy efficiency, casement windows generally offer a slight advantage due to their compression seal design. However, modern sash windows have significantly improved and can achieve comparable performance levels.
At Bereco, both our casement and sash windows exceed the new Part L 2023 building regulations. Our double-glazed timber windows achieve impressive U-values starting from 1.3 W/m²K – which is 7% better than current guidelines.
Choosing the right window style for your property
For period homes
Traditional sash windows typically suit Georgian, Victorian, and Edwardian properties better, maintaining architectural authenticity while providing modern performance.
For contemporary homes
Casement windows often represent the better choice for modern properties, offering clean lines and maximum glass area for contemporary aesthetics.
For mixed architectural styles
Many properties benefit from different window types in different areas. Consider sash windows for street-facing elevations and casement windows for rear extensions or modern additions.
Bereco’s bespoke wooden window customisation
At Bereco, we understand that every home is unique. Our bespoke timber windows can be customised to meet your specific needs, regardless of whether you choose casement or sash windows.
Design options include:
– Bar designs: Traditional glazing bars or contemporary clean lines
– Ironmongery styles: 10 different metal accents to complement any architectural style
– Paint finishes: Thousands of colour options for single or dual-colour combinations
– Stain finishes: Natural wood tones to highlight timber grain
– Mouldings: Various profiles to match your property’s character
– Acoustic options: Sound reduction up to 42dB with our Ambient range
Regardless of style, all our timber windows use sustainably sourced FSC® 100% or 100% PEFC Origin certified softwood or hardwood. Our manufacturing process ensures a 60-year+ lifespan with a 10-year warranty and low maintenance requirements.
Making your decision: key considerations
Property type:
– Period homes: Traditional sash windows often suit better
– Modern properties: Casement windows typically complement contemporary design
– Mixed styles: Consider different window types for different areas
Practical requirements:
– Easy maintenance: Casement windows offer simpler cleaning
– Space constraints: Sash windows don’t project outward
– Maximum ventilation: Casement windows open fully
– Noise reduction: Both styles available with acoustic glazing
Budget considerations:
Material costs vary depending on complexity and customisation requirements. Our team can help you find the perfect balance between performance, aesthetics, and budget.
Get expert advice for your window project
Choosing between casement and sash windows depends on your property type, personal preferences, and specific requirements. Our experienced team at Bereco can help you make the right choice for your home.
We offer a complete service including design consultation, manufacturing, and installation. Our live window visualiser allows you to see how different window styles will look on your property before making your final decision.
Ready to explore your options? Contact us today for a free quote and expert advice on the best window solution for your home. Complete our online contact form, call us on 01709 838188 or email info@bereco.co.uk .
