NYC DOB requires work permits for virtually all construction activity including alterations, new buildings, demolition, and equipment installation. Two filing tracks: (1) Professional Certification — PE or RA self-certifies code compliance, faster approval (1-2 weeks), spot-audited by DOB. (2) DOB Plan Examination — full DOB review, 4-12 weeks typical, required for certain project types. Required documents: drawings signed/sealed by PE or RA, structural calculations, energy code compliance (NYC Energy Conservation Code), zoning analysis, site safety plan (for buildings over 15 stories or adjacent to occupied buildings). NYC-specific requirements: Special Inspections per BC 1704, Site Safety Manager for major buildings (cost $1,500-3,000/week), Licensed Site Safety Coordinator, after-hours work permits (AHV), sidewalk shed and scaffolding permits, crane permits. Fees: based on cost of work, typically 1-3% of construction value. DOB NOW is the online portal for all filings.