How to Measure Irregular Structural Openings

When speaking to a door manufacturer, it is important to know your structural opening size to get a quote and receive a door that will fit. Measuring a structural opening can become even more complicated for retrofit projects, where the structural opening maybe be irregular. We are going to break down the step-by-step guide to measuring structural openings – both even and irregular structural openings below.

What is a structural opening?

The structural opening is the gap between the wall, whether it be masonry or timber, for a window, door, or passageway. If there is an existing frame, the structural opening does not start from or over the frame, the structural opening is always from wall to wall.

How to measure a structural opening?

To determine the width, we take three dimensions at the top, middle and bottom of the frame. For the height, measure the height of the left hand and right hand of the frame.

If it is a new-build or new door, there should be no or little variation in the measurements. However, if there is some difference, take the smallest width and smallest height to send to your door manufacturer.

How to measure an irregular structural opening?

To determine the width, we take three dimensions at the top, middle and bottom of the frame. Once you have recorded the three measurements and discover the wall is irregular, take the smallest dimension.

For the height, measure the height of the left hand and right hand of the frame. Again, take the smallest dimension of the two measurements as the structural opening.

Once you have the two smallest dimensions for width and height which you can then give to the door manufacturer as the structural opening who will then provide you your frame size.

How to measure a structural opening where there is an existing wall and frame?

Firstly, it is important to note the structural opening is the gap between the structure, for example the blockwork, and not the gap between the frame or over the frame.

To determine the width, measure the structural opening at the at the top, middle and bottom of the structural opening. Take the smallest of those three dimensions.

Similarly, for the height, measure the height of the left hand and right hand of the frame. Again, take the smallest dimension of the two measurements.

Once you have the smallest width and height measurements, send this to your chosen door manufacturer.

What happens if there is a large variance between the largest and smallest dimension?

This will mean that there will be a gap between the frame and wall at the largest gap in the structural opening. This is why we invented the adjustable architrave system, which gives installers up to 20mm of flexibility between the thickness of frame and the thickness of the wall. The difference in thickness between the wall and frame can be taken out by the adjustability inherent in the architraves.

If required, we can provide a list of approved installers to ensure your doorset is compliant. In addition, we provide training through our Academy to demonstrate the gold-standard approach to installing our doorsets.

If you have any questions or would like to book an Academy training session or find an approved installer, please contact sales@selo.global.