Traditional sash windows made from timber have a striking and unmistakable charm. These used cords, weights and pulleys to help the sashes move, but timber framed windows don’t have the qualities and properties of uPVC. As such, while uPVC sash windows keep the sliding design and aesthetic, they do use different mechanisms. So how do uPVC sash windows work?
What is a uPVC sash window?
A uPVC sash window consists of one or more movable sections, known as sashes, which slide vertically within the window frame. This makes it possible to open and close the window without swinging it inwards or outwards.
There are two different design options available: a single sash that moves, or two sashes that can slide independently. Either option allows you to control how much of the window is open and where the ventilation enters the room, and the best choice will depend on your preference and your requirements.
What are the main parts of a uPVC sash window?
There are a number of different components involved in uPVC sash window design, and they all play a role, working together to allow the window to open, close and remain securely in position. These parts include:
The window frame
One or more sliding sashes
Glass panes
Glazing bars where required
Seals around the opening sections
Locks and other hardware
How does a uPVC sash window open?
uPVC sash windows open by sliding the sashes vertically rather than opening on hinges. This means that in a typical design, you move the lower sash upwards to allow fresh air into the room. Some designs also allow the upper sash to move downwards, giving you greater control over ventilation.
The sashes are supported by a balance system inside the window, which helps make them easier to move and keeps them in position when opened, so that you can open the window to different heights depending on the amount of ventilation you need.
How does the sash mechanism work?
For modern uPVC sash windows, these typically use spring balances or other modern balance systems. These counterbalance the weight of the sash, which means that you can move the window easily.
However, it’s important to note that the exact mechanism can vary depending on the manufacturer and window design.
Can both sections of a sash window open?
Many uPVC sash windows are designed with two independently moving sashes, which allows you to open the lower sash from the bottom and the upper sash from the top. Having both sections open can help improve airflow through the room.
Are uPVC sash windows energy efficient?
Modern uPVC sash windows can provide good levels of thermal insulation, particularly when fitted with energy-efficient double glazing. This is because the uPVC frame helps reduce heat transfer, while the glazing and seals help prevent warm air from escaping through the window. This can help your home feel warmer and more comfortable, particularly during colder months.
However, the overall energy performance will depend on factors such as the window design, glazing, installation and condition of the surrounding property.
Are uPVC sash windows secure?
uPVC sash windows can also provide good levels of security when fitted with suitable locks and hardware. Modern sash windows can include features such as:
Multi-point locking systems
Secure sash fasteners
Strong window frames
Toughened or laminated glass where appropriate
Restrictors for controlled opening
What are the benefits of uPVC sash windows?
uPVC sash windows combine the traditional sliding design of sash windows with the practical benefits of modern uPVC. Some of the main benefits include:
A traditional appearance
Vertical sliding operation
Good ventilation control
Low maintenance requirements
Modern double glazing options
Improved thermal insulation
A range of colours and finishes
Modern security features
uPVC sash windows are a great way to add or keep the traditional look of a sash window while benefiting from modern materials, glazing, security and lower maintenance requirements. With different styles and finishes available, you can choose an option that suits both the character and needs of your property.