What Are the Standard Window Sizes

What Are the Standard Window Sizes in the UK?

Windows come in a wide variety of sizes depending on the different styles of the frame. When considering replacing your windows you need to get the right measurements from your existing windows so that you can compare. If you have unusual sizes, you will need a manufacturer that can produce bespoke made-to-measure frames.

A standard house window size

Most manufacturers do offer standard window sizes in the UK, although some houses may have bespoke sizes or shapes. If you are replacing your windows, it’s essential to get the right measurements for the windows before you can start to look at the window sizes.

As measurements need to be perfect, it is always better for an installer to measure for you to get the right window size. An the end of this article, we explain how to measure your windows.

The Standard House Window Sizes in the UK

Standard sizes vary between different styles of windows, so please refer to the tables below.

Standard uPVC Window Sizes

The most popular material for windows in the UK, uPVC windows offer a versatile frame and a variety of size options.

Average uPVC window height:

Inches (in)Millimetre (mm)
59 in1500 mm
53.1 in1350 mm
47.2 in1200 mm
41.3 in1050 mm
23.6 in600 mm
17.7 in450 mm

Average uPVC window width:

Inches (in)Millimetre (mm)
69.7 in1770 mm
47.2 in1200 mm
36 in915 mm
24.8 in630 mm
19.2 in488 mm

Standard Casement Window Sizes

Casement windows are the most popular style of window in the UK and they are the most versatile window, available in many different configurations. So, the industry doesn’t specify a standard size.

Despite this, many manufacturers do offer a range of sizes for casement windows.

The most common standard sizes for single casement windows:

Inches (in)Millimetre (mm)
25 x 35 in635 x 890 mm
29 x 74 in736 x 1194 mm
29 x 59 in736 x 1498 mm

Everest Windows Are All Made To Measure

All our windows are custom fit to any size.

Tilt & Turn Window Sizes

Tilt and turn windows are a practical window solution for any blocks of flats and other locations that are above a storey in height.

When considering the size of a tilt and turn window, you are limited by the height to width ratio. Once the opening section becomes wider than the height, that is how wide you can go. Otherwise, you'll be placing too much strain on the hinges or there might not be enough room to open them internally.

Single Tilt and Turn Window
  • Minimum size of 600mm (23.6in) by 500mm (19.7in)
  • Maximum size of 1900mm (74.8in) by 1300mm (51.2in)

Double Tilt and Turn Window Sizes
  • Minimum size of 600mm(23.6in) by 1200mm (47.2in)
  • Maximum size of 1700mm (66.9in) by 2400mm (94.5in)

Triple Tilt and Turn Window Sizes (2 Outer Opening Panes)
  • Minimum size of 600mm (23.6in) by 1600mm (62.3in)
  • Maximum size of 1900mm (74.8in) by 3000mm (118.1in)

Standard Sash Window Sizes

Sliding sash windows are a classic style of window, most often found on period properties.

Most period sash windows were built during the Victorian and Edwardian periods. At that time, the standard width for sash windows was approximately 1.2 m (4 feet). So most period sash windows fit this size.

Sash window standard widths:

Inches (in)Millimetre (mm)
36 in914 mm
48 in1219 mm
60 in1524 mm
72 in1829 mm
84 in2134 mm

Sash window standard heights:

Inches (in)Millimetre (mm)
24 in609 mm
36 in914 mm
48 in1219 mm
60 in1524 mm

Sash window sizes can vary widely, especially for any windows built before and during the Georgian era. If your property has a non-standard size window, you will require bespoke size frames to be made. At Everest, we do offer made-to-measure sash windows.

Standard Bay Window Sizes

Bay windows are an excellent way to create a stylish focal point at the front of your property whilst flooding a room with light. Because they protrude out from the wall, they can also provide additional space for seating or storage.

Bay Window Standard Width
  • Minimum size 3 foot 6 inches (101.6cm)
  • Maximum10 foot 6 inches (320cm)
Bay Window Standard Height
  • Minimum 3 foot (91.44cm)
  • Maximum 6 foot 6 inches tall (198.12cm)

The Size of Windows in Different Rooms

Generally, rooms in the home will have windows of different sizes because the light and ventilation requirements are not the same in every room. Plus, you might have smaller windows in a bathroom, for example, to maintain privacy levels.

Bathroom windows

Your bathroom windows will most likely be the smallest windows in the house. The standard size for them will depend on which type of window they are (casement, sliding sash, etc.).

Living Room Windows

Living rooms tend to have the largest windows in the home. The lounge is one of the most frequently used rooms and often the focal point of the property, it's important for the windows to look good and allow in plenty of light. Sliding sash, bay and casement windows are commonly used for living rooms.

Kitchen Windows

The height of windows in a kitchen will differ depending on where they are located. For example, windows located above the sink are calculated by considering the height of your kitchen cabinets and the thickness of the countertop. Any windows that are fitted above a backsplash will need to consider the height of the backsplash.

Bedroom Windows

In the past 20 years, larger bedroom windows have increased in popularity.

Standard bedroom window sizes:

Inches (in)Millimetre (mm)
24 x 36 in610 x 914 mm
24 x 46 in610 x 1168 mm
28 x 54 in711 x 1371mm
28 x 66 in711 x 1676 mm
28 x 70 in711 x 1778 mm
34 x 46 in863 x 1168 mm
34 x 62 in863 x 1574 mm

How to Measure Windows

Always measure your windows from the outside. Use a good metal tape measure and hold it taut and make sure it’s vertical or horizontal point to point across the frame or window aperture.

Take three measurements, one in the middle and two towards the edges. Use the smallest measurement. Repeat this for the height and width.

Also, measure your windows from corner to corner to make sure they are square.

Check your measurements several times. You do not want to get these wrong.

A window needs some tolerance when it’s fitted so manufacturers will deduct between 5-10mm from measurements to make an allowance.

Read our full article: How to measure a window...

Everest Window Styles

Casement Windows →

  • Highly thermally efficient
  • An array of colour options
  • Smooth or woodgrain
  • Highly secure

Tilt & Turn Windows →

  • Opens in for easy cleaning
  • Tilts for secure ventilation
  • An array of colour options
  • Smooth or woodgrain

Bay Windows →

  • A sense of space and light
  • Panoramic views
  • Four different configurations
  • uPVC, timber or aluminium

Sash Windows →

  • Replica traditional design
  • Smooth running mechanisms
  • Smooth or woodgrain
  • Traditional sash furniture

Tell Us Your Vision and We'll Provide the Solution

At Everest, we make improving your home simple. From the initial design visit to installation, we take care of it all, from start to finish.