If you are not sure about the correctness of the measurements, you can occasionally meet who perform this service

Measuring aluminum windows is a must if you want a new window that pleases you.
In order to order a new window and know its cost, please use the instructions below:

Instructions for measuring a window opening in a home with a quarter.
In houses with openings with a quarter, the window must go 20-30 mm beyond the top and side exterior soffits (Fig. 1, A). Therefore, you should consider this standard when measuring window openings.

Fig. 1. Measuring the width of the window in the opening with a quarter.
Window width (Fig. 1, D) - measured from the outside soffits (Fig. 1, A) and added 40-60 mm for the window to fit into the quarter from 2 sides (or slightly less, if the wall is heavily curved).
After measuring the width between the outside lining (Fig. 1, A) and getting the window width (Fig. 1, D), check that the window width (Fig. 1, D) is not greater than the distance between the abutment points of the inside lining to the frame (Fig. 1, B). Also, the width of the window (Fig. 1, D) must never exceed the width of the internal opening (Fig. 1, C). If these conditions are not met, then something went wrong and you need to repeat everything again more carefully.

Fig.2. Measuring the height of the window in an opening with a quarter.
The height of the window (Fig. 2, H) - is the distance from the base of the window opening to the outer upper slope (Fig. 2, F) minus 10-20 mm (the gap under the foam) and plus 20-30 mm (setting of the window in the upper quarter).
If you install the window will be used under the stand profile, and it is a prerequisite, when installing the window sill and sill, the height of the window (Fig. 1, H) should be further reduced by 30 mm (height of the underlying profile).
To check the correctness of the measurement, check the following dimensions, without the undercut profile window height must be less than the distance from the window sill to the top internal lining (Fig. 2, E) and with the undercut profile window height must not exceed the distance from the bottom edge of the sill to the top internal lining (Fig. 2, E+G).

Instructions for measuring a window opening in a house without a quarter.
To measure the window, take the width and height of the window opening. When measuring the width, you should measure at the top and bottom of the opening and use the smallest value in further calculations. From the obtained width of the opening, you must subtract 20-40 mm (gaps on the foam on 2 sides), this will be the width of your aluminum window. The height of the opening should also be measured from the left and right sides of the opening. From the smallest height subtract 20-40 mm (gaps in the foam on top and bottom), and 30 mm (height under the base profile, if it is needed), the resulting value and will be the height of the window.

If you have any questions with measurements of your windows you can write to us on WhatsApp +31 6 81 55 96 17, as well as use the services of a professional who has extensive experience in installing aluminum windows.