How to Measure for Replacement Windows (and What the Numbers Have to Clear)
Measuring for replacement windows is three measurements, not one, and the number that matters most is not the one you write on the order. It is what is left after the new frame and sash take their share — the opening a person could climb out of. This page shows both, and what each one has to clear before an inspector signs it off. 5.7 sq ft minimum clear opening for escape, IRC R310 $22,073 ten vinyl windows, national benchmark $26,781 ten wood windows, national benchmark 1.19× highest region over lowest Figures from the International Residential Code; the Cost vs. Value Report. The three measurements, and why you take three of each A replacement window is ordered to a number you cannot take back once the glass is cut, so this part is worth doing slowly. Measure the width in three places: across the top of the opening, across the middle, and across the bottom. Measure the height in three places too, at the left jamb, up the center, and at the right jamb. Then measu...