Casement Window Cost
A casement window is hinged at the side and opens outward like a door, offering excellent ventilation and unobstructed views.
Average Price Range
Energy Rating
Security Rating
Typical Lifespan
Casement windows represent one of the most versatile and efficient window designs available in the UK market. Hinged at the side like a door, these windows open outward, offering unobstructed views and excellent ventilation capabilities. Their design creates a tight seal when closed, making them exceptionally energy-efficient compared to other window styles. This seal not only prevents drafts but also enhances security, as the hook-shaped casement locks embed deeply into the frame. Originally popularized during the Tudor period in Britain, casement windows have evolved significantly while maintaining their fundamental appeal. Modern versions feature advanced locking mechanisms, friction hinges that hold the window in any desired position, and multi-point locking systems for enhanced security. The versatility of casement windows makes them suitable for virtually any room in your home. They can be installed individually, in pairs (French casement style), or as part of a larger window configuration. The outward opening design makes them ideal for areas where interior space is limited, such as above kitchen sinks or countertops. Available in various materials including uPVC, aluminum, timber, and composite, casement windows can complement any architectural style from traditional to contemporary. Their clean lines work well in modern settings, while period designs with leaded glass or Georgian bars suit heritage properties. Energy-efficient double and triple glazing options further enhance their performance, making them an excellent investment for reducing heating costs and environmental impact.
Advantages
- Excellent ventilation
- Good security when closed
- Energy efficient with tight seal
- Easy to operate
- Unobstructed views
Disadvantages
- Can be caught by wind when open
- Limited size options for very large openings
- Opening mechanism may deteriorate over time
Best Suited For
Most residential homes
Kitchens and bathrooms
Areas requiring good ventilation
Casement Window Replacement Costs
The table below shows average replacement costs for Casement Window windows of different sizes, including supply and installation. Prices may vary based on specification, glazing options, and your location.
Window Size | Supply Only | Installation | Total Cost | Time to Install |
---|---|---|---|---|
Small (600 × 900mm) | £375 | £150 - £250 | £575 | 2-3 hours |
Medium (1000 × 1200mm) | £650 | £200 - £300 | £900 | 3-4 hours |
Large (1200 × 1500mm) | £1,000 | £250 - £350 | £1,300 | 4-5 hours |
Extra Large (1800 × 2100mm) | £1,425 | £300 - £450 | £1,800 | 5-6 hours |
Cost Factors
Factors that increase cost:
- Triple glazing (+15-25%)
- Acoustic glass for noise reduction (+10-20%)
- Enhanced security features (+5-15%)
- Custom finishes or colors (+5-10%)
Ways to save on cost:
- Multiple window replacement discount (10-15%)
- Standard sizing rather than custom dimensions
- Off-peak installation (winter months)
- Comparing quotes from multiple installers
Cost Comparison by Material
Different materials affect both the initial cost and long-term value of your Casement Window windows. Below we compare typical costs and benefits:
Material | Price Range | Energy Efficiency | Lifespan | Maintenance |
---|---|---|---|---|
uPVC | £520 - £650 | Good (A-C) | 20-25 years | Low |
Aluminum | £780 - £975 | Good (B-C) | 30-40 years | Low |
Timber | £910 - £1170 | Good (B-C) | 30+ years | Medium-High |
Composite | £1040 - £1300 | Excellent (A+) | 30-40 years | Low |
Long-Term Value Considerations
While uPVC is typically the most affordable option for Casement Window windows, materials like timber and composite may offer better long-term value when considering lifespan, property value enhancement, and energy savings.
Initial Investment
uPVC offers the lowest upfront cost, while composite materials represent the highest initial investment.
Energy Savings
Composite and modern timber windows often provide the best thermal performance, resulting in higher energy savings.
Property Value
Timber and composite windows typically add more to property value, especially in period properties.
Key Features
Full opening for maximum ventilation
Easy to clean from inside
Excellent seal when closed
Compatible with all frame materials
Opening Mechanisms

Side-Hinged
Window opens outward from a side hinge like a door.
Advantages
- Provides full opening
- Good for emergency exits
- Simple mechanism
Disadvantages
- Requires space outside for opening
- Can be caught by wind

Top-Hinged
Window opens outward from a top hinge.
Advantages
- Allows ventilation during light rain
- Secure opening option
- Less affected by wind
Disadvantages
- Limited opening angle
- Not suitable for emergency exit
Maintenance
Maintenance Requirements
Medium - hinges and handles require occasional lubrication
Typical Lifespan: 20-30 years
Casement Window Variations

Top-Hung Casement
Hinged at the top instead of the side, opening from the bottom.

French Casement
Double casement windows that open from the center with no central mullion.
Material Options
Excellent Compatibility
uPVC
Excellent Compatibility
Most common combination - affordable and practical
Aluminum
Excellent Compatibility
Creates a modern look with slim sightlines
Timber
Excellent Compatibility
Traditional look, often used in period properties
Composite
Excellent Compatibility
Premium option offering best of both worlds
Installation Guide
Installing Casement Window typically involves measuring the window opening, removing existing windows, preparing the opening, and installing the new window frame. Professional installation is recommended to ensure proper fitting, sealing, and functionality.
Installation Process
- Measuring - Accurate measurement of the window opening
- Removal - Careful removal of existing windows
- Preparation - Clean and prepare the window opening
- Installation - Position and secure the new window frame
- Sealing - Apply proper sealing to ensure weatherproofing
- Finishing - Complete internal and external finishing work
- Testing - Check operation and make adjustments
Professional Installation
Professional installation ensures proper fitting and sealing
Installers have the right tools and equipment for the job
Installation typically takes 1-2 days depending on the number of windows
Professional installation often includes warranty and after-service