Planning guide
How to Measure an Entry-Door Opening
Early measurements help the design conversation, while final production dimensions require field verification by the responsible project party. Measure more than one point and document what each dimension is taken between.
Record width, height and diagonals
Measure width at the top, middle and bottom; height at the left, center and right; and both diagonals. Keep all readings instead of reporting only the largest number.
Show wall and floor conditions
Photograph the opening from both sides and record wall thickness, exterior cladding, waterproofing zone, finished floor levels and any step or drainage condition.
Separate rough and final dimensions
Label early information as approximate. Before release, the responsible contractor should confirm the agreed datum, tolerances, frame clearance and the final dimensions recorded on the approved drawing.
Frequently asked questions
Should I measure the old door or the structural opening?
For replacement work, record both when accessible and identify finished surfaces. The drawing review will clarify which dimensions govern the proposed frame.
Can production start from homeowner measurements?
Rough homeowner measurements can start a discussion, but final production dimensions should follow the project’s agreed verification and approval process.
Apply this guide to your opening
Share the information you already have. Unknown items can remain open for review.