How to measure windows

Accurate measuring of your windows before ordering them is crucial. If you are not an experienced DIY enthusiast, we would strongly advise to ask a professional to assist you.

Basic tips:

It is essential that you measure the inside of the overall opening at the top, the middle and the bottom. Also check the height and record all your findings. This type of measuring is then to be repeated from the outside. Only then can you make an informed judgement on which combination of sizes will allow the window, which comes with its own frame, to fit.     

We would also advise that you take a total of 10mm from the width and height to give some fitting tolerances. It is not uncommon to have to make the Upvc door or window/frame smaller to ensure it can fit. If necessary timber packers can be fitted behind the frame to take up any clearance (they can be easily concealed with facings).

Golden rules:

• Measure three times, order once

• Measure the inside as well as the outside brick opening

• Measure in several places, three times, record all measurements to find the smallest size, remove around 10mm from both height and width to ensure snug installation of windows

See also

Why triple glazing ? How to measure windows ?