"No building or structure regulated by this code shall be erected, constructed, enlarged, altered, repaired, moved, improved, removed, converted or demolished unless a separate permit for each building or structure has first been obtained from the Building Official."
This means that almost anything done to a structure, other than cosmetic improvements (painting, carpet, linoleum, floor coverings, wallpaper, etc.) requires a building permit.
Common Projects That Require Building Permits
Replacing water heater
Patio covers and shade structures
Above ground pools over 5,000 gallons
Detached storage or accessory structure exceeding 120 square feet in floor area.
Re-roofing - including overlays which cannot exceed three layers.