Windows & doors · definition
IRC minimums for an emergency escape opening — clear width, height, area (about 5.7 sq ft), and max sill height — that govern bedroom/basement windows.
Source: Andersen Windows — Window & Door Glossary
Where this term lands on a Columbus budget
The cost pages carry the current local ranges, and the guides explain what moves them. A published range becomes a project number only after someone looks at the site.