The Performance-Based Fire Engineering (PBFE) practice of Thornton Tomasetti, a large multidiscipline engineering firm headquartered in New York. Staffed from its NYC headquarters, the team evaluates fire risk with physics-based CFD and finite-element modelling of fire dynamics, smoke propagation, structural response and human evacuation, developing performance-based alternatives to prescriptive fireproofing for complex and mass-timber buildings — modelling that informs, and does not substitute for, the design team’s professional judgement.