Permitting is local, not universal
Building codes, zoning rules, and permit requirements are set at the city or county level, not nationally. That means the same project can require different documentation depending on exactly where it's built. We don't guess at this—your jurisdiction's requirements get confirmed as part of your quote, and your plan set is scoped to match. See How the Permit Process Works.
Engineering: when a stamp is required
Some projects need calculations and drawings sealed by a licensed structural engineer—not just drafted, but reviewed and stamped by someone licensed in your state. This is common for second stories, long spans, load-bearing wall removal, and in counties with stricter structural requirements. See When Do You Need a Structural Engineer?
Site plans: the document permitting almost always requires
A site plan shows how your project sits on the lot—property lines, setbacks, and the relationship between the structure and the rest of the site. It's one of the most consistently required documents across jurisdictions. See Site Plans Explained.