To measure your structural opening, firstly ensure there is no pre-existing frame installed. All of our steel doors come with their frame. For the strongest installation, we recommend bolting our steel frames directly into the aperture, whether it be brick, steel or wood.
Take 3 measurements for the width at the top, middle and bottom of the opening and take the smallest measurement. Then, take 3 measurements for the height, at the left side, middle, right side and take that smallest measurements too.
Your structural opening is the smallest width x smallest height.
Watch the explainer video above for further advice.