Aluminium Windows Opening Types




Windows are essential to any residence or building. The main functions of windows are to let in natural daylight, all whilst providing ventilation and connection to the outdoors. In addition to these main functions, the windows must meet aesthetic, energy efficiency, acoustical and security requirements. So, selecting the right windows is depending on many factors whilst you are building a brand-new home or renovating an older home. Since the opening type can change most of these functions of windows, it is crucial to pick the proper opening type while considering windows in your building project. So, you should consider the type of window opening that fits your requirement the best.

There are a variety of different opening types for windows. The opening type of a window specifies how the window opens. 

Windows can be classified according to its opening functions: 

  • Casement window
  • Inward opening side-hung window
  • Inward opening turn&tilt window
  • Inward opening bottom-hung (tilt only) window
  • Outward opening side-hung window
  • Outward opening top-hung window
  • Sliding window
  • Folding window
  • Pivot opening 
  • Fixed window

Casement window

A type of window that is attached to its frame by one or more hinges on either side. The casement opening is the most popular opening type comprising of a traditionally opening framed window. It is economical and widely used with a basic and uncomplicated design and a straightforward opening style. Although casement windows are often referred to as side-hinged windows, the opening casements can be side-hung, bottom-hung or top-hung on hinges attached to the window frame.

Inward opening side-hung window

It is a traditional side-hung (turn) window, and the sash of the window can be attached to the either side of the frame by hinges. By operating the handle, window sash opens inwards like a door.

When it is opened fully, the side-hung window allows maximum ventilation into the area, can be cleaned very easily on both sides.

A side hung window can be designed with visible hinges or concealed hinges.

Inward opening – Turn&tilt window

A tilt-turn window has a dual hinge system and offers two different vent opening styles: tilt opening and turn opening. When the vent is on “tilt” mode,  the top of the vent is slightly opened inwards for more secure ventilation. When the vent is set on “turn” mode, the vent swings open fully (90 degrees) like a side-hinged window.

Depending on combination of the handle positions, tilt turn windows can be designed in two operating styles:

  • Turn-tilt: first turned and then tilted.
  • Tilt-turn: first tilted and then turned.

Tilt mode provides an efficient way for ventilation whilst maintaining the security and the turn mode is used for cleaning, emergency exit or full ventilation. A tilt and turn window has a restricted opening of typically between 10 and 15 degrees.


  • Ideal for properties directly on a street or by a pavement where an outward-opening window would be both a hazard and security risk.
  • This allows for adequate ventilation, making them ideal for offices, businesses, hotels and flats.
  • The safety and cleaning options make this style of window increasingly popular as they are beginning to be incorporated in many newly built flats. 
  • Ideal as a fire escape as window opens fully like a door
  • provides perfect solution for Juliet balconies where ventilation and uninterrupted views are the main priorities

Tilt-turn windows can be design with visible hinges or concealed hinges. Because of dual opening mechanism, aluminium tilt and turn windows are a little more expensive than side-hung windows.

Inward opening – Bottom-hung (tilt only) window

This element is equipped with either a handle or a spring latch. By operating the handle or spring latch, the window sash will move to a tilt position.

Outward opening – Side-hung window

That is the another traditional and popular window type in the UK. It is side hinged and the handle is located at the centre on the window.

Outward opening – Top-hung window

The window sash can only open up to a limited angle and it can be cleaned only from the outside. Because the sash opens outward, it has no sash in the room that disturbing sill ornaments, curtains or blinds.

Horizontal sliding window

It is a type of window constructed sliding panes mounted on a track and open horizontally by sliding. It is an easy opening window and doesn’t need any exterior or interior space for opening. It can be designed at large larges for uninterrupted views and suitable ventilation. It suits most architectural styles and can be used in both residential and commercial buildings.

Like sliding doors, horizontal sliding windows comes with double-track (rail) or triple-track (3-rail) options. Double-track sliding windows allow 2-panels or 4-panels sliding windows and triple-track sliding windows allow 3-panels or 6-panels sliding windows.


  • They can be used any places where you wouldn’t want a window to protrude.
  • Because they open and close without protruding, horizontal sliding windows are ideal solution for hallways and rooms facing walkways.
  • As they are easy-opening, horizontal sliding windows are ideal for using over kitchen countersand sinks, 
  • full height sliding windowscan be used for Juliet balcony applications for uninterrupted views and maximum ventilation.
  • As providing large openings, they are very practical windows for fire escapes. 

Aluminium horizontal sliding windows are usually more expensive than other options and are less thermally efficient when comparing to casement windows.

Folding window

Folding window sashes can be folded open in a specific opening sequence. A folding window system creates the ultimate opening area.  In this system, the glazed elements are folded to the in -or outside of a wall by use of a rail.

Vertical pivot opening 

The pivot sash is secured to the window frame by a pivot mechanism. The mechanism is located vertically at or near the center of the window. Pivot windows allow a wider opening than is common with other window types. The design of a pivot window also allows for larger than standard window sizes.

Horizontal pivot opening

Having one sash only, the horizontal pivoted sash hinged swings open vertically. Typical applications for horizontal pivot windows are large sized openings in commercial or residential buildings where the design calls for an unobstructed view and large window sizes.

Horizontal sliding windows can be used: 

  • Above kitchen sinks and counters for easy opening
  • When you need full height opening (balustrades are used on first and above) 
  • When you need large size opening windows for uninterrupted views. 

Fixed window

As the name suggests, fixed glazed windows are fixed and don’t have any sash. Since they are not openable and don’t provide any ventilation, fixed windows can be used in situations where only light or vision is needed.   


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