The sizes of replacement designs will be dependent on what type of house you own, the period it was built and its overall style.
If you hire the expertise of a qualified window installer, they’ll see that the right window sizes are fitted, determined after they’ve thoroughly measured your home’s openings.
Before that time comes, we thought it helpful to advise you of the most common window sizes in the UK so that you get a rough estimate of what window sizes will be required.
UPVC Windows
The appeal of UPVC windows is largely due to their affordability and undemanding upkeep. Here’s a list of their average sizes:
- Heights: 600mm, 1050mm, 1200mm, 1350mm, 1500mm
- Widths: 488mm, 630mm, 915mm, 1200mm, 1770mm

Casement Windows
A hugely popular style because of their versatility. The typical casement sizes are:
- 635 x 890mm
- 736 x 1194mm
- 736 x 1498mm

Tilt & Turn Windows
With an opening function that removes troublesome cleaning, tilt and turn windows are generally sized as such:
- Single: 600 x 500mm (min), 1900 x 1300mm (max)
- Double: 600 x 1200mm (min), 1700 x 2400mm (max)
- Triple: 600 x 1600mm (min), 1900 x 3000mm (max)

Window Guidance For Rooms
Bathroom – Windows fitted into bathroom areas normally include frosted or obscure glazing and are smaller than average.
Living Room – For maximum light gain in living rooms, windows tend to be larger than elsewhere.
Kitchen – Kitchen windows are generally placed higher up and have a shorter length, often situated above a sink.
Bedroom – Windows for bedrooms are so mixed, ranging from wide openings to condensed designs.

Materials & How They Shape Sizes
Sizes are impacted by the window material chosen. Three materials account for most window sales:
UPVC: Obey standard sizes in most instances, while also being economical and simple to fit.
Timber: Tailored timber windows are often employed at listed and traditional homes.
Aluminium: Modern aluminium frames put glass before profile to exaggerate views.

Mitchell Glass organises window measuring for all its customers so that when it comes to the day of fitting your replacement openings, everything runs smoothly.
Got eyes on having new windows this summer? Better get them booked in now to avoid disappointment – click here without delay.
LOOKING TO REPLACE YOUR WINDOWS?
We have a fantastic range to choose from so whether it’s a modern style or traditional timber effect windows – we are confident that we will have windows to improve any home to give it the finished look with elegance.
LOOKING TO REPLACE YOUR WINDOWS?
We have a fantastic range to choose from so whether it’s a modern style or traditional timber effect windows – we are confident that we will have windows to improve any home to give it the finished look with elegance.
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Want to speak with an Advisor? Give us a call on 0800 220 415
Our friendly team will be pleased to help with any questions you may have.