What are Casement Windows?
November 10, 2017
Painting the Windows at Home
How to Paint Sash Windows
September 5, 2018

Window Parts Definitions

Familiarising yourself with all the different parts of a window is probably not a task that ranks high on your priorities’ list. In fact, this may not even be something that you have ever considered worth doing. However, if you are planning to install or replace some of your windows, getting to know the key vocabulary used in the window industry is of a vital importance. Companies that are dealing with the manufacturing, installation and maintenance of windows use a professional glossary when they are discussing projects with their clients. Therefore, if you want to make a wise investment and to be able to effectively communicate your window needs to retailers, manufacturers, handyman pros etc., you must first learn the definitions of the key parts of any window. So, grab a pen and piece of paper and dive into our window parts glossary guide.

Casement window parts

Casement windows are like doors. They are attached to their frame through hinges. Those hinges can either be at the side of the frame, at the bottom or at its top. The most obvious advantage of having casement windows is that they are easy to operate. Plus, you can open them fully and naturally ventilate any room.

  • Frame – All casement windows have a frame. This part keeps everything together and it can also come in various designs and colours. A frame consists of three main parts: a head, a sill and side jambs. The head and the sill are the two horizontal parts that make up the frame. The head is set at its top and the sill – at its bottom. The jambs, on the other hand, are the two vertical parts which you find on each side of the frame.
  • Glazing – This is the piece or pieces of glass which are held by the sash. Older windows tend to be single-glazed but double-glazing windows are the most popular glazing options today.
  • Glazing bars – Some casement windows have glazing bars that create the illusion that the glazing of the windows is made up of smaller pieces of glass.

In terms of hardware, casement windows are very simple as usually, it all comes down to handles and lavers. For example, most such windows have a lock lever which is installed on their jamb. Awning casement windows, on the other hand, also come with a crank handle which you can use to open or close the window.

Alternatives to common window parts terms

The commonly used term in the UK Alternative terms and synonyms
Cill Sill
Bottom rail Lower rail
Top rail Upper rail
Glazing Glass
Crank handle Operator
Finger lifts
Lock lever Lock handle

Windows Handle Detailed

Sash window parts

Even though there are theories claiming that the sash window is of a Dutch origin, it is generally believed that this type of a window was invented in England in the 17th century. It continues to be a popular feature on many Georgian and Victorian homes in the UK which is why we have decided to pay special attention to this type of window. The benefits of opting for this option when choosing windows for you your home or office are numerous. That is especially true if you decide to use high-quality sash windows because they are available in various designs and they offer a good sound reduction, lower condensation rates and higher security and safety levels.

Sash Windows with Glazing Bars

Just like casement windows, sash windows have a frame, glazing and sometimes glazing bars too. However, there are a few other parts which make up this type of window and those include:

  • Sashes – Although the word “sash” comes from French and it originally means “frame,” this part of the window is separate from its frame. Most sash windows consist of two sashes – a top and a bottom sash for hung sash windows and left and right sash for horizontal sash windows. These are the movable parts of this type of window and they also serve as a frame that holds the window’s glass.
  • Meeting rail – Where the two sashes meet.
  • Top & bottom rails – The former is the top part of the top sash and the latter is the bottom part of the bottom sash.

Sash window hardware glossary

If you need to make slight modifications and repairs on your sash windows, you will also need to expand your hardware vocabulary. The handles you can find at the bottom of the window are called sash lifts and they help you to easily set the sashes in the desired position. To lock the sashes, you use a so-called sash lock which is installed on the meeting rails. There are three main mechanisms associated with this type of windows – weighted, balance tubes and spring loaded. The latter is what you will find in modern sash windows and it is hidden behind the building profile of the window for aesthetic purposes.

Now that you know so much about window parts, you can make more informed decisions the next time you need have a window fixed, replaced or installed.