Windows are an integral part of any building and serve as portals that connect the exterior world with the interior of the structure. They are provided as openings in the walls that allow natural light, fresh air, and views of the outside world. There are different types of windows with various styles, designs, functions, and unique features. Casement windows are one of the widely popular window types that are in use. This blog gives a clear picture of what a casement window is, its types, installation, pros, cons, and more.
Overview of Casement Window
A casement window is a type of window that has been in use since the mediaeval period. These windows have shutters that are hinged to the frame at one side and the windows can be opened and closed like a door. Grooves or rebates are provided on the frame for the functioning of the shutters. The shutter panels in a casement window may be single, double, or multiple. Casement windows are available in UPVC (Unplasticized Polyvinyl Chloride), timber, and aluminium.
Types of Casement Windows
Side Hung
This is one of the most common types of casement windows, where the window is hinged at the side, and the shutter swings outward.
Single Casement
This is a basic type of window that has a single panel hinged on a side and swings outwards.
Double Frame
It is a double-panel window with both the shutters hinged on the sides. They have a central mullion with window handles in the centre. These windows open outwards to have a large opening. This window is also called a French casement window.
Top Hung
This window is hinged at the top and is opened from the bottom. They are opened outwards towards the top. These windows are ideal to prevent rain from entering the building during wet climatic conditions. This window is also called an awning window.
Bottom Hung
This window is hinged at the bottom and is opened from the top. These windows are ideal for apartments and upper floors that require safe opening. This window is also called a hopper window.
Flush Casement
It is a thin frame, where the window sits flush in the frame when closed. This window type gives a contemporary finish with aluminium frames.
Fixed Casement
It is a type of casement window where the opening sash is fixed and cannot be opened. This type of window does not provide ventilation, but only light.
Advantages and Disadvantages of Casement Windows
Advantages
- These windows provide maximum ventilation due to their wide openings.
- These windows are easy to clean and maintain.
- They are highly energy efficient.
- These windows come in various ranges of styles, colours, and materials.
- They are flexible and can be used for every type of building.
- They provide aesthetic beauty to the property.
Disadvantages
- Casement windows are hard to install and require highly skilled labour.
- They are more expensive than most of the other window types.
- Faulty casement windows are insecure, as they are easy to break into.
- The sizes of casement windows are limited and fixed, unless customisation is opted for (which becomes more expensive).
Installation Process for Casement Windows
Prerequisites Before Installing
Before installing casement windows, it is crucial to check:
- The measurements of the place of installation are accurate, which guarantees a proper fit.
- Check for level openings, and straight edges, so that the windows work properly and last longer.
- Check whether the structure is free from air leaks, water pooling, sealing failure, and have the ability to tolerate the window fittings.
- Select the right casement windows that are high quality, have good ratings, and are durable.
Step-by-Step Installation Process
- The places where the windows need to be fixed are cleared from damage and the tolerances are fitted based on the frame size.
- The frames are positioned correctly in the openings and the horizontal and vertical levelling are checked using the levels and the plumb bob. The wedges can be used to position the frame at the point before permanent fixing.
- After fitting the frame in the rough opening, the concealed gaps are sealed using waterproof silicone caulk on the exterior sides.
- After fixing the frames, the sash (shutters) are checked for movements. Any undulations in friction and bindings can be adjusted by using screws.
- After fixing the casement window, the fixing is double-checked for sealings and imperfections to ensure secure functioning.
What are the Different Parts of a Casement Window?
Window Frame
The window frame holds the casement window in place and is made up of a head and a sill that runs horizontally from top to bottom. They are joined with two jambs that run vertically on either side.
Window Sill
Window sills form the bottom of the window frame, which has a sloped or curvy finish to direct the water away from the window.
Casement
Casement is a part of the window that opens and secures the glazings in place.
Mullion
It is a vertical strip that is made of uPVC, timber, or aluminium and separates the sashes (window units).
Transom
It is a horizontal strip that supports the mullion and helps to keep the window units separate.
Lock Handle
It is the window’s lock that helps in opening and closing the window. It is placed on the casement jamb.
Trickle Vent
It is placed on the top of the window and consists of a grill on the outside and a closing vent on the inside.
Georgian Bars
These are vertical and horizontal bars that create the classic look of the glass that divides the windows into small square units.
Astragal Bars
These are fitted on the top of the window both inside and outside in a single piece of glazing.
Casement Windows vs Sliding Windows
| Casement Windows | Sliding Windows |
| Casement windows open completely and allow more unobstructed views and more ventilation. | Sliding windows open halfway, which obstructs the view allowing minimal ventilation and light to pass in. |
| They provide great energy efficiency. It seals the door completely when closed, not allowing external temperatures to affect the internal room temperature. | The slide runners at the top and bottom of the window allow air to pass through. These windows cannot be closed completely which makes them less energy efficient. |
| They require periodical maintenance for the crank, lever, and handle. | They have low maintenance as they have no cranks. Only the sliding channels need period cleaning to ensure smooth movement. |
| They are expensive and require skilled labour for installation. | These are budget-friendly compared to casement windows. |
| Need external opening, which could obstruct sidewalks. | The sliders don’t require external space for opening the window. |
Conclusion
Casement windows are one of the most popular and widely used windows in construction. They provide a combination of aesthetic looks, maximised ventilation, energy efficiency, and security. Although they are expensive and require highly skilled labour for installation, they justify it by providing numerous benefits.