A guide to casement windows

Casement windows blend style, security, and functionality seamlessly, making them popular among homeowners. 

The most frequently installed type of window, casement windows have side, top, or bottom set hinges and swing outwards, providing full ventilation. They are available in a wide range of designs, sizes, and colours and cost an average of £500, making casement windows one of the cheapest options when installing double glazing.

Our window experts explain everything you need to know about casement windows – from new windows’ cost to the best style for your home, making your decision easy.  

Casements operate through a hinge mechanism attaching the window to the side, top, or bottom of the frame and can open outward to the left or right, or inward, depending on the design. 

They are operated by a small latch/fastener handle or crank handle located opposite the hinges, which also serves as the locking mechanism, ensuring the window remains securely shut or firmly held in position when open.

Casement windows’ ability to provide excellent ventilation, unobstructed views, enhanced security features, and energy efficiency contribute to their widespread appeal.

Most manufacturers produce several types of casement windows.

Single casement

Single casement windows consist of one large pane of glass hinged on one side, allowing them to swing open either inward or outward. They are simple, elegant, and versatile, fitting well into both traditional and contemporary architectural designs.

Double, or French, casement

Double casement windows, also known as French casement windows, have two sashes that open outward from the centre without a mullion in the middle, offering a full, unobstructed view. These windows are often chosen for their romantic, classical appearance and wide opening, facilitating ventilation and serving as an emergency exit route.

Push-out casement

Push-out casement windows are distinguished by their simple handles, allowing for manual opening. Unlike other casement types that rely on a crank mechanism, the push-out variant provides a more streamlined look that’s favoured in designs aiming for a minimalist finish.

Swing-in casement

Swing-in casement windows are designed to open inward, which can be particularly useful when exterior obstacles prevent a window from opening outward. This design also facilitates easier cleaning of the window from the inside.

With their diverse styles and mechanisms, casement windows offer something for every home, blending seamlessly with any architectural design while providing functionality, security, and energy efficiency. Their ability to adapt to different architectural styles and functional requirements makes them a popular choice in a wide range of residential settings.

The cost of casement windows can vary widely based on several factors, including size, material, and glazing type. 

Generally, casement windows are considered to offer good value for their cost, especially when factoring in their energy efficiency, which can lead to long-term savings on heating and cooling expenses. 

Size

The size of the casement window significantly affects its price. Larger windows require more materials for both the frame and the glass, and the increased weight necessitates more robust hardware to operate the window smoothly. Therefore, as the window size increases, so does the cost. 

Material

The frame material is crucial in determining the cost of casement windows, with uPVC, aluminium and timber being the most common. 

uPVC is often the most cost-effective option, offering good insulation and low maintenance, while wood typically carries the highest price tag. Although admired for its thermal properties, aesthetic qualities, and longevity, wood windows require regular maintenance. 

Aluminium casement windows are known for their durability and slim frames, but they can be less energy-efficient unless equipped with a thermal break – a gap of at least one cm between the double glazing panes. 

Glazing type

The type of glazing also impacts the price of casement windows. Double glazing, consisting of two panes of glass with an air or gas fill in between, is most commonly seen in new windows. They provide better insulation, energy efficiency, and substantial savings over time compared with the single glazed units they might replace. 

Triple glazed windows, offering even better energy performance and noise reduction, are between 10 and 20% more expensive but can be justified in extremely cold climates or if your energy bills are particularly high.

Maintaining casement windows ensures their longevity, smooth operation, and energy efficiency. The routine maintenance required can vary depending on the material of the window frame.

• uPVC: uPVC frames are very low maintenance, requiring only occasional cleaning with soapy water to keep them looking their best. Check the seals regularly to ensure they remain tight and efficient.
• Aluminium: Aluminium frames are also low maintenance but should be cleaned periodically to maintain their finish. Check for signs of corrosion, particularly in coastal areas where salt air can be more abrasive.
• Wood: Wooden windows require more upkeep due to their vulnerability to moisture and temperature changes. Regular painting or staining is necessary to prevent warping, rotting, or other water damage. Inspect for signs of wear and treat any discovered issues promptly to prevent deterioration.

For all materials, it’s crucial to lubricate the hinges and moving parts annually to ensure smooth operation and to inspect the hardware for any signs of wear or damage.

Common problems 

Casement windows can face several common issues, with repair costs varying based on the severity.

Difficulty opening or closing

If you’re experiencing difficulty opening or closing your windows, problems can often be resolved by adjusting or replacing the hinges or the crank mechanism. Costs for new hinges or a crank mechanism can range from £10 to £50, with labour adding to the price if a professional is required.

Faulty seals

Replacing or repairing failed double glazing seals can help eliminate draughts and condensation. Seal replacements might cost between £50 and £100, plus labour. However, in some cases, the window unit may need to be replaced entirely, costing an average price of £500.

Rot or corrosion

For wooden frames, repairs can cost anywhere from £100 for simple DIY tasks, such as sanding or repainting to over £1000 for extensive damage requiring professional restoration. 

Aluminium frames might need repainting or anodising, which could cost several hundred pounds depending on the extent of corrosion and the size of the window.

Hardware replacement

Replacing worn or broken handles, or locks can typically cost between £20 and £100 for the parts, with additional costs for labour if you’re not doing the work yourself.

Timely maintenance can prevent many of these issues from becoming serious, saving money in the long run. For significant repairs or replacements, it’s advisable to get multiple quotes from professionals to ensure competitive pricing.