If a project includes cutting or modifying framing, moving or removing walls, changing roof lines, upgrading an electrical panel, relocating plumbing, or adjusting window and door sizes, permits are almost always required. These activities affect structural integrity, life safety, or core building systems, which places them squarely under local code oversight. Another clear indicator is when a manufacturer’s installation instructions mention code compliance, inspections, or specific dimensional requirements. Egress windows are a common example, as they must meet minimum opening sizes and sill heights defined by building codes to ensure safe escape during emergencies. Mechanical equipment, decks, and major remodels often carry similar requirements. When there is uncertainty, it is safest to assume a permit applies and verify with the local building department before work begins. Confirming early helps avoid delays, fines, failed inspections, or costly rework later in the project.