Decide the mounting plane
An inside mount sits within the jamb or recess and needs enough clear depth. An outside mount covers the opening from the wall or trim. Record the exact surface where the frame or panel will land rather than mixing glass, sash, trim, and rough-opening dimensions.
Measure width and height more than once
Measure width near the top, middle, and bottom. Measure height at the left, center, and right. Record every value exactly, including fractions, and note the smallest and largest measurements. Do not average a tapered opening without an approved fitting rule.
Document depth and obstructions
Measure usable jamb depth at the shallowest point. Photograph handles, locks, cranks, screens, tilt-in sashes, alarm contacts, mullions, protruding sills, trim returns, furniture, faucets, and anything that can block louvers or panels.
Check square and identify each opening
Compare diagonals and use a level where possible. Assign a stable room and opening ID, then pair it with photos taken square-on and from both corners. The ID should remain with the quote, drawing, packaging, and installation notes.
Turn the guide into a complete opening schedule.
Keep every finished width and height, mounting surface, jamb depth, panel arrangement, material, finish, hardware part, photo, and delivery note connected to the same opening ID.
Start the configurationQuestions about this topic
Should I round shutter measurements?
No. Record the actual measurements and fractions. The manufacturer or approved fitting rule—not the person measuring—should decide deductions and final production size.