Casement Window vs Sash Window

Comparison Overview

When comparing Casement Window and Sash Window, several key differences become apparent. In terms of cost, Sash Window are approximately 55% more expensive than Casement Window, with average prices of £550 and £850 respectively. This price difference reflects variations in design complexity, materials, and installation requirements. For energy efficiency, Sash Window offer better thermal performance with an efficiency rating of 0.0%, compared to Casement Window's 0.0%. This translates to potential differences in household energy savings. Casement Window provide superior security features, which is an important consideration for homeowners concerned about safety. Casement Window typically have a lifespan of 20-30 years, while Sash Window last approximately 20-25 years. Casement Window are particularly suitable for Most residential homes and Kitchens and bathrooms, while Sash Window excel in Period properties and Victorian and Georgian homes. Maintenance requirements vary between the two styles, with implications for long-term ownership costs and convenience. Your choice between these window types should ultimately depend on your specific needs, including budget constraints, energy efficiency goals, security requirements, aesthetics, and the architectural style of your property.

Casement Window

Casement Window window

A casement window is hinged at the side and opens outward like a door, offering excellent ventilation and unobstructed views.

Sash Window

Sash Window window

A traditional window style consisting of one or more movable panels (sashes) that slide vertically or horizontally in the frame.

Average Price

£550

Casement Window

£850

Sash Window

Energy Efficiency

0.0%

Casement Window

0.0%

Sash Window

Security Rating

High

Casement Window

Medium

Sash Window

Customer Rating

4.7/5

Casement Window

4.5/5

Sash Window

Detailed Comparison

Casement Window
Sash Window
Average Price
£550
£850
Energy Efficiency
0.0%
0.0%
U-Value
1.2 W/m²K
1.4 W/m²K
Energy Rating
A
B
Average Warranty
15.0 years
12.0 years
Reliability Score
0.0/5
0.0/5
Customer Satisfaction
4.7/5
4.5/5
Security Rating
High
Medium
Noise Reduction
Medium
Medium
Ventilation
4.8/5
4.2/5
Maintenance
Medium - hinges and handles require occasional lubrication
Medium-High - sliding channels require regular cleaning and lubrication
Typical Lifespan
20-30 years
20-25 years

Features Comparison

Casement Window
Sash Window
Full opening for maximum ventilation
Easy to clean from inside
Excellent seal when closed
Compatible with all frame materials
Traditional appearance
Sliding mechanism rather than hinged
Available in single or double-hung styles
Good for period properties

Best Suited For

Casement Window Best For:

  • Most residential homes
  • Kitchens and bathrooms
  • Areas requiring good ventilation

Sash Window Best For:

  • Period properties
  • Victorian and Georgian homes
  • Conservation areas
  • Traditional aesthetics

Pros and Cons

Casement Window

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

Sash Window

Advantages:

  • Traditional aesthetic
  • No outward opening space required
  • Good for period properties
  • Available in various configurations

Disadvantages:

  • More complex to manufacture
  • Can be drafty in older designs
  • Typically more expensive than casement
  • Moving parts may require maintenance

Cost Comparison

The table below shows typical costs for Casement Window and Sash Windowin different sizes. Prices include window and installation.

Window SizeCasement WindowSash WindowDifference
Small (600 × 900mm)£385£595Save £210 with Casement Window
Medium (1000 × 1200mm)£550£850Save £300 with Casement Window
Large (1200 × 1500mm)£715£1,105Save £390 with Casement Window
Bay/Bow (Custom Size)£1,375£2,125Save £750 with Casement Window

Additional Cost Considerations

Installation Complexity:

Casement Window windows typically are less complex to install compared to Sash Window windows, affecting labor costs.

Long-term Value:

Consider energy efficiency ratings and durability - Sash Window windows offer better long-term energy savings.

Factors Affecting Price

Window Material Options

  • uPVC: Most affordable option (1x base price)
  • Aluminum: More expensive (1.5-2x base price)
  • Timber: Premium option (2-3x base price)

Other Price Factors

  • Glazing options (double vs triple)
  • Security features and hardware quality
  • Property access and installation difficulty
  • Regional price variations (higher in London/SE)

Energy Efficiency & Performance

Casement Window Windows

Energy Rating:A
U-Value:1.2 W/m²K
Noise Reduction:Medium
Ventilation Rating:4.8/5

Sash Window Windows

Energy Rating:B
U-Value:1.4 W/m²K
Noise Reduction:Medium
Ventilation Rating:4.2/5

Energy Efficiency Comparison Summary

Both window types offer similar energy efficiency ratings, but may have different strengths in terms of noise reduction, ventilation, and other factors.

About U-Values

U-value measures how well a window prevents heat from escaping. Lower numbers are better - a window with a U-value of 1.2 W/m²K loses less heat than one with 1.6 W/m²K.

Building regulations require new windows to have a U-value of 1.6 W/m²K or lower. Windows with values below 1.0 W/m²K offer excellent thermal performance but typically cost more.

Energy Savings Potential

Property TypeCasement Window Annual Savings*Sash Window Annual Savings*
Small (1-2 bedroom flat)£79£76
Medium (3 bedroom house)£126£121
Large (4+ bedroom house)£183£177

*Estimated annual savings when replacing single-glazed windows. Actual savings will vary based on your property's insulation, heating system, and local climate.

Maintenance & Lifespan

Casement Window Windows

Typical Lifespan:20-30 years
Average Warranty:15 years

Maintenance Requirements:

Medium - hinges and handles require occasional lubrication

Sash Window Windows

Typical Lifespan:20-25 years
Average Warranty:12 years

Maintenance Requirements:

Medium-High - sliding channels require regular cleaning and lubrication

Maintenance Comparison

Maintenance TaskCasement WindowSash Window
Cleaning2-4 times per year2-4 times per year
Hardware LubricationAnnuallyAnnually
Seal InspectionEvery 1-2 yearsEvery 1-2 years
Weather StrippingReplace every 5-8 yearsReplace every 5-8 years
Professional ServiceEvery 2-3 yearsEvery 2-3 years

Maintenance Tips

Extending Window Lifespan
  • Clean tracks and hinges regularly
  • Use silicone spray on moving parts annually
  • Check and replace weather stripping as needed
  • Inspect and repair caulking to prevent leaks
Signs Windows Need Replacement
  • Difficult to open or close
  • Visible condensation between glass panes
  • Drafts even when closed
  • Rotting frames or water damage

Security & Safety Features

Casement Window Security Features

Security Rating:High

Common Security Features:

  • Multi-point locking systems
  • Reinforced frames for added strength
  • Laminated or toughened safety glass options
  • Internal beading to prevent glass removal
Enhanced Security Features Available

Sash Window Security Features

Security Rating:Medium

Common Security Features:

  • Multi-point locking systems
  • Reinforced frames for added strength
  • Laminated or toughened safety glass options
  • Internal beading to prevent glass removal

Security Certifications to Look For

Secured by Design (SBD)

Police-backed initiative that certifies products meeting strict security standards.

BSI PAS 24

British Standards Institute certification for enhanced security performance requirements.

Safety Glass Options

Toughened Glass

Heat-treated to make it 4-5 times stronger than regular glass. If broken, it shatters into small, less dangerous pieces rather than sharp shards.

Laminated Glass

Contains a plastic interlayer that holds the glass together if broken. Offers higher security and better sound insulation than standard glass.

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